L2: Response to Global Change Flashcards
What is biodiversity?
The variety of animals, plant and organisms in an environment
What are essential biodiversity variables (EBVs)?
variables that are monitored to assess biodiversity
1. Genetic composition
2. Species populations
3. Species traits
4. Ecosystem function
5. Community composition
6. Ecosystem structure
What are some challenges associated with biodiversity observations?
- Country biased - better data in more developed countries
- Taxonomic bias - more likely to detect or have better data of vertebrates, less data on insects
- Costly- requires a lot of techniques and variables that makes it costly, meaning there are many gaps
- Time series - requires funding and can be difficult as variables are changing
- Sampling bias - sampling using of presence and not absence. Sometimes sampling effort is known and not random
What are some drivers of biodiversity change?
Land use
- decrease in forest cover 2.3million km squared between 2002 and 2012
Climate change
- 19 of the hottest 20years have been in this century
Fishing
- 33% of fisheries are unsustainable
What are the two main types of models?
Static - represents ecosystem at a single point in time
Dynamic - represents ecosystem and associated changes over time
What are the components of a biodiversity model? What are some challenges?
- Data
- Predictors
- Model patterns and functions
- Predictors
Challenge
- No control as a pristine undisturbed state
- Assumes that interactions and changes are the same throughout time (in reality tipping points could be reached)
- requires biological processes such as metabolism and behaviour
What data is used for species distribution modelling?
- Occurrence records e.g. historical appearances
- Environmental variables e.g climatic suitability
- Co-occurring pests and pathogens to analyse the environmental suitability of new areas and potential for spread
= Can help generate probability of appearance
What are the uses and challenges associated with static-pattern based models?
Uses
- Predict where species will be distributed
- Plan conservation plans by identifying areas at risk
Challenges
- Unable to identify a causal relationship
- Global change is multidimensional
Why are processes important to include within a model?
- Captures biological processes
- Generates better more accurate predictions
- Identify gaps and generate predictions e.g. weather patterns
- Useful for conservation and management
Describe and give an example of a trait-based approach to modelling
Madingley model
- Uses functional traits of organisms to group them, as many species aren’t well described
Groups based on age, energy consumption (diet) etc
What is a cohort based approach to modelling?
Look at traits within a population along with the abundance
What is the Madingley model?
Ecological model designed to simulate the dynamics of an ecosystem
- Uses individual based modelling (IBM) and ecological processes that link cohorts together
e.g. Metabolism cohort that is dependent on temperature
Predation that is dependent on model size and body mass of predators
What are the planetary boundaries?
Safe limits for human pressures on 9 critical processes that help maintain Earth’s state
- Passing these limits means surpassing tipping points that can have irreversible effects
Some changes are buffered overtime e.g. extinction rates
How do people depend on nature?
- Plants release O2
- Plants absorb up to 30% of anthropogenic CO2, limiting global warming
- Further 25% is absorbed by the sea and by calcareous organisms
- Pollination
- Plants and animals provide resources such as food
e.g. fisheries, logging, cattle farming and agriculture
How can biodiversity have a positive effect on ecosystem functions?
Greater variety so greater number of services provided
- Important for nutrient recycling
- increase in diversity leads to increased biomass
- increased pollination success
Selection effects - more species leads to greater competition, selecting for well performing organisms
Complementarity- more likely to have species complementing each other
What evidence is there for the role of higher trophic levels in the Earth system?
C content was found to be affected by the number of mammals
- likely due to their role in feeding and transfer of carbon between different stores
Size selection - historically animals used to be bigger, however, with the changing climate larger animals are at greater risk of extinction
What are the predictions for the future of biodiversity? How accurate are these predictions?
- Decrease in biodiversity due to a combination of land use change and climate change
- Increase in extinction rates and risk, particularly due to habitat loss and climate change
- Homogenisation of communities due to migration of species
Accuracy
- feedback mechanisms are hard to take into account, but likely present and may generate a positive feedback loop
- data quality only shows previous temperatures and land uses, highs that have not really been reached before so hard to predict
- variation of effects on biodiversity is great between different ecosystem types
What is the relevance of fire?
Economic cost - can cause billions of dollars of damage
Agriculture burning - important for land clearing, common method in India for rice fields
Habitat loss - destruction of well developed forest, but also important for resetting and there are trees that are adapted to fires
Biogeochemical reset- nutrient recycling (depending on thermal transformation threshold of certain elements) can increase nutrient availability in soil, but no too frequently
What are the different type of fires?
Surface - burning of shrub and low lying vegetation
Crown - burning of the forest crown (upper canopy). Greater devastation though less common
Ground - burning of material/soil in the ground, hard to control and track
Ladder fuels that help link up to the crown
What types of environments are well adapted to fires and which aren’t?
Savannah’s well adapted
- grasslands that commonly see fire, trees adapted to resprout after fires
Some forests
- Pine and Sequoia rely on fires for underbush clearing and trees are well adapted to regenerate or have a thick bark
Tropical forest NOT well adapted
- not adapted to periodic fire, commonly too humid for fire to spread
Woodlands NOT well adapted
- not commonly exposed to fires so not well adapted
What are the regulators of fire?
- Amount of fuel
- Type of fuel
- Environmental conditions (hot and dry)
- Vapour Pressure Deficit
(difference in the amount of water in the air and how much water the air can hold)
What global changes can increase the risk of and severity of fires?
- Mesophication - shade tolerant trees replace fire resistant trees. Increases risk of a big fire
- Fire-suppression - reduces frequency of fires but increases risk that a big fire will occur and cause greater damage as trees are also less likely to be adapted. Also leads to more fuel accumulating
- Climate change altering weather patterns can increase the amount of lightning strikes, which can start fires
What are novel disturbances?
Change in the intensity and frequency of disturbances as a result of anthropogenic action. To more extreme boundaries and away from historical baselines
What are the three different forms that novel disturbances can take?
- Intensification of the disturbance - larger, longer fires
- Addition of another disturbance - more drought and loss of soil moisture
- Interactions between disturbances (+ve or -ve)
- burning can lead to less fuel and less extreme fires, in addition to reducing competition for water and so increasing soil moisture content
What are baselines how are they derived?
They are normal rate of occurrence
Generated from historical data and predictions of a baseline dependent on contributing factors
e.g. precipitation and temperatures associated with certain patterns and intensity of fires
Experimentally confirmed
- mimicking of past environments and periods of drought can be done to analyse the effect on the populations and changes in fuel abundance or fire risk
How can fires be associated with both positive and negative density dependence?
Positive density dependence - number and severity of fires increase with increasing population size. Due to more fuel, greater competition for water and drier conditions
Negative density dependence - number and severity of fires decreases with increasing with population size. More trees causing more shading and limiting grass growth which is important for fuel
How does density dependence effect changes in biomass over time in response to dife?
Positive density dependence
- severity of fires decline, but so does biomass. because the they are dependent on each other
Negative density dependence
- severity can increase while biomass declines at a faster rate. Rate of recovery isn’t enough to prevent severity, few trees left standing that are still able to burn
Describe the interaction between disease and burning
Certain diseases in trees can increase the fuel load by generating dead standing trees
- disease spread follows positive density dependence which promotes more fires
Regular plot burning - important for removing fuel and reducing tree density to limit spread and amount of fuel
Lack of plot burning can lead to increase in tree density and biomass but increased risk of a large crown fire and a rapid reduction
How can aridity effect the fire severity?
Low aridity - wet and promotes forest growth so lots of fuel but unfavourable conditions for a fire. More cover promotes retention of water and so negative density dependence
High aridity - potentially associated with minimal vegetation and fuel; however, perfect conditions. Forms part of positive density dependence
How is fire associated with global warming? Include some spatial effects
Increase in aridity as a result of warming correlates with increased the occurrence of fires in Western USA
Higher latitudes are more effected as they undergo greater change in albedo due to melting of ice and are less adapted to fires
- Also more likely to experience ground fires and burning of permafrost
(generating a positive feedback loop by releasing more carbon in addition to promoting more microbial activity for decomposition)
How can forest type be altered as a result of novel disturbances and their effects on fires?
Hotter and more frequent fires promote deciduous forests, over conifer forests
- Deciduous trees support higher frequency fires as they shed leaves
Change towards trees that regenerate better after a fire and are more resistant to fires
- plants that are more efficient at capitalising from the nutrients and the environment (e.g. change in light) following a fire are more likely to excel
How can the effects of changing heat and drought differ across the globe?
In analyses of photosynthesis
Heat was found to be a greater driver for change at higher latitudes
Drought was found to be more impactful for areas at lower latitudes
What is resilience? How has climate change altered the resilience of ecosystems?
Resilience is the ability of a system to resist changes
Climate change has caused the thresholds for resilience to change, making it more likely that a system will not be resilient and change as a result of disturbances
What is DOC?
Dissolved Organic Carbon
- free C pool that is easily accessible
What anthropogenic effects can have an effect on DOC?
- Deforestation
- Agriculture
- tillage and rotation can prevent C from being returned to the soil - Urbanisation
- changes soil composition and movement of water and carbon within - Climate change
- changes in the soil moisture and water availability
How is soils formed? (5)
- Time
- Climate - temp and energy regulation
- Parent material - nutrients and ease of breakdown
- Topography - basins and water table
- Biota - breakdown
What are the 4 different horizons in the soil?
O = lead litter
A = leaf litter
B = subsoil
C = parent material
How can anthropogenic factors alter the formation of soil?
Agricultural practices
- disruption of microbial communities, so less decomposition of
Pollution
- contamination with chemicals, altering the structure and nutrient cycling also harming plant health
Deforestation
- reduction in roots holding soil together, can lead to leaching of soil nutrients and soil erosion
What factors effect the quantity and quality of soil?
Quantity - dependent on the net productivity from plants
- Commonly, increased root mass is associated with increased DOC
Quality - depends on litter quality and how easy it is to break down. Also relying on the presence of microbes for effective decomposition
What is recalcitrant and labile litter?
Recalcitrant - hard to break down e.g. lignin
Labile litter - easier to break down e.g. cellulose, hemicellulose
What are some climate mitigation strategies to improve soil quality while maintaining crop yield? (6)
- Changes in agriculture
- growth of legumes to increase N content in soil
- growth of plants with deep roots to increase DOC
- reduce burning of crop land to allow for decomposition and recycling of nutrients - Reducing deforestation
- hard as there is an economic need, but important to maintain DOC levels - Cover cropping
- Crop rotations to prevent soil erosion and boost soil nutrients for cash crops - Increase in atmCO2
- to promote photosynthesis and plant growth NOT EFFECTIVE in increasing soil C content - Biochar
- for carbon sequestration, made from heating up organic matter - Afforestation
- has to be right to have an effect on biodiversity, grasslands found to store more carbon than woody forests
What is the carbon budget?
carbon is not added or removed from the system, instead the movement between different stores can change
What changes in carbon dioxide have there been?
1.45 fold increase since pre-industrial period, now reaching 422ppm
Milankovitch cycles generate fluctuations, but this rate of change has not been seen before
Evidence - ice cores, direct measurements
What are the book-keeping models and dynamic global vegetation models?
Bookkeeping
- actual observations from satellites, doesn’t make predictions
Dynamic Global Vegetation models
- model that simulates interaction between vegetation and the climate, generating predictions
Describe the changes in methane
2.4 fold increase since the preindustrial period
Due to cattle farming (greater release from burps than farts) and paddy fields
Describe the changes in nitrous oxide
1.24 fold increase
Due to agriculture use, mainly ammonium nitrate fertiliser use
Describe the spatial distribution of contributors to climate change
Uneven - greater contribution by HICs such as N.America, Europe. Lowest contributors include Asia and Africa
Vulnerability - commonly LICs that are the lowest contributors
What are the predictions of the future effects of climate change?
- More extreme weather
- Increase by 3 degrees will lead to loss of species
- Increase in 3 degrees has detrimental effects on food production (fisheries and maize yield)
What are some methods of climate mitigation?
- Carbon capture and sequestration
- Renewable resources of energy
- Net-zero land use change
- Max 1.5 degree increase
- Alter cow feed to decrease methane release
- Reduce fertiliser usage
- Restoration of peatland
What are some problems associated with climate change mitigation?
Large finance gap
- great investment is needed to implement the strategies
Feasibility
- of changing peoples minds and diets are difficult
What is the role of GAMs?
General Additive Models
- Capture nonlinear relationships and interactions without requiring specific information on form etc.
- Models how populations change in response to multiple environmental factors e.g. seasonal changes in populations due to breeding cycles, food availability and climatic events
How has temperature affected populations?
BENEFIT - populations that are limited by cold, resulting in increased survival rate. Higher latitudes benefit more at least for most terrestrial organisms, however, fish show a negative correlation
NEGATIVE - populations that live in already hot areas e.g. near the equator which have already adapted to work at their maximal rate
Migration changes
- changes in temperature may alter where bird populations migrate to
How has water availability affected populations?
Plants - higher temp, more drought = water stress and death. Increase in rainfall can lead to flooding and anoxic conditions, also negative
Birds - Change in vegetation structure and location for nesting, drought = bad. Migratory birds relying on water bodies for rest and refuel, drying out of lakes can have a detrimental impact .
- Drought has a negative effect on breeding success
LINK - birds can act as pollinators and seed dispersal for plants, habitat alterations linked to water availability
How has changes in sea temperature affected populations?
Ice melt - increased access to food for penguins to feed their young, can increase survival rate. Although ice/ habitat area decreases
Spatial re-allocation - movement of marine animals in response to changing temperatures. Plankton (base of food web) may move to cooler and then provide less prey for larger marine organisms and consequently birds
= NEGATIVE correlation between increase sea temperature and population size
Why might the effects of climate change on bird populations differ?
Altricial - helpless chick more affected by biotic changes
Precocial - independent chick, doesn’t receive parental compensation so more affected by biotic factors and hypothermia
- Increase in bird mass with increasing number of frost days (smaller surface are to volume ratio to minimise heat loss)
How has climate change altered biotic factors that influence bird populations?
- Decrease in cane fly due to drying of peat resulting in larvae death
- Correlation between food abundance and population size, negative correlation between temperature and prey abundance
- Mismatch between peak food availability and breeding cycles, needing to feed offspring
- Change in vegetation cover can increase predation risk, e.g. changing in timing so that leaf loss exposes nests and renders chicks more vulnerable
What are some examples of climate change changing the timings of biological processes/
- Change in peak food availability
- Early flowering can result in change in peak population size as they may not coincide - Reliance on ephemeral sources
- e.g. of water can alter and mismatch with population dynamics - Disease spread
- spread may be more prevalent at certain temperatures of the year
e.g. avian malaria may spread from lowlands to uplands due to the shift in species distribution
How might density dependence dispersion be affected by climatic suitability?
As climate suitability decreases the density decreases
- e.g. moving away from ideal temperature and climate will result in a decrease in the population size
Normal distribution with greatest population size found in the centre of range where the conditions are most ideal
Describe the changes in species range that have been observed
Bird populations
Moving away from equator at 16km per decade
Moving ‘upwards elevation’ at 12.2m per decade
- lag behind likely due to greater differences in the environment at different elevations
What are the expected changes to diversity (of birds) as a result of climate change?
Increase in biodiversity due to warming at higher latitudes
Migration of birds northwards, increasing the number of species
Homogenisation - loss of uniqueness and increasing similarity between different habitats
Describe the diversity of birds in general
Greater diversity in mountainous areas due to fragmentation of habitats and niches that are formed
Lower diversity in savannahs due to lack of vegetation and generally lower diversity
Describe bioclimate modelling
Models interactions between the climate and populations
1. Matches the current distribution of populations with environmental factors such as temperature, water availability and soil quality
2. Models changes in these environmental factors (much easier than looking at biotic)
3. Using climatic suitability assumptions, can then predict changes in the population
= Have suggested that many populations in Europe will move northwards as a result of warming
How is species vulnerability assessed?
Factors to look at
- exposure to climate change e.g. sign temp changes, precipitation changes
- sensitivity
- adaptive capacity
- geographic range
= If these are significantly threatened by climate change then the species could be assessed as being vulnerable
+ requires modelling of the expected changes as well as data collection
(Bryophytes and mosses have been found to be particularly sensitive to climate change)
What are cropping systems?
Patterns of crops that are grown in a field, in addition to the management techniques used
Compare industrial agriculture and agoecological farming
Industrial agriculture - monoculture, highly mechanised, singular outputs and high external inputs
Agroecological farming - diverse crops, local adapted varieties used, minimal external outputs
What is organic agriculture?
Agricultural system that sustains soil health and the ecosystem
Using varieties that are locally adapted and without external inputs such as pesticides
What are the 5 pillars for regenerative agriculture?
- Diversity
- Livestock integration
- Protect soil surface
- Minimise soil disturbance
- Maintain living roots
What are some indicators for soil quality?
- Chemical - nutrient, pH
2 Biological - fungi and bacteria - Physical properties - porosity
What are different tillage techniques and how do they effect the soil?
4 types: shallow/deep tillage, strip tillage, direct drilling (no tillage)
- disrupt soil microbe communities
- can increase porosity
- greater release of CO2 and methane from microbial activity and soi store
- cost and greenhouse emission of machinery for tilling
What are cover crops and what are the different types?
Crops that are planted to prevent soil degradation and increase yield of cash crops
1. Catch crop
- oilseed radish preventing nitrate leaching by 75-97%
2. Green manure
- positive effect on C sequestration, legumes increasing N content
3. Biofumigant
- Striga species that are weeds, application of SL to promote suicidal germination, or growth of plants with reduced SL synthesis
4. Companion crop/ Intercropping
- can promote AMF colonisation and increase N content in soil by growing with legumes e.g. Desmodium
What are the benefits of crop rotation? What is an example of this?
Helpful for controlling pathogen spread, and prevent weed growth
Including legumes in one of the rotations can help increase N content, average yield increase of 20%
N. China plains (Yang et al., 2024)
- double cropping within one year, using a total of 8 species (including legumes)
- Improvement in GHG emissions and soil health
- Found an increase in yield
What is ISSM?
Integrate Soil and Water Management
Concept in agronomy that focuses sustainable management of the soil of water
- Including effective irrigation methods
- Ensuring biodiversity
- Cover crop to maintain soil health
What is the importance of maintaining diversity within crop species and in general?
Variety is important for wheat- certain cultivars and protein content have to be specific
- important for developing disease resistance and analysing new traits
- reducing reliance on one sole crop that could be wiped out by a disease
20 of species make up 90% of the food eaten
What are the different ways in which pathogen spread in crops can be mitigated?
Dilution - reducing the number susceptible individuals
Physical barrier
Premunition - activation of immunity (SAR)
Compensation - maintain yield using another variety
What are some alternatives to meat for protein?
Plants
- Lentils, Soya, beans and peas
Insect based protein
Precision fermentation e.g. quorn
Cell-culture meat
What are challenges with changing the main source of protein towards plant-based protein?
- Beans and peas have low yield in respect to area, compared wheat
- Changing people’s diet
Chickpea - salinity, drought stress, weeds and competition
Describe the properties of Teff
Cereal that has high nutritional content and is gluten free, commonly grown in Ethiopia
- Adapted to water logging and drought conditions
- Seeds that are formed are very small, sowing is seeds is by random dispersal
- Prone to lodging, due to long stems and short root. However the stem is important for straw and social uses
What is a method for increasing diversity of crops grown while maintaining yield?
Data-driven decentralised breeding
- Increase the variety of crops grown in an area but making informed decisions using information about climate
What is crop perennialization? What are the positives and an example
Aim to transform annual crops to perennial varieties, living for multiple yields without the need for replanting
- Doesn’t require tilling and disruption of microbial communities
- Lower labour costs
- Lower fertiliser use
Perennial rice (Orzya longistaminata)
- maintains yield over 4 seasons
Why is N fertiliser important for crop growth and yield?
In most environments N is a limiting factor for growth
- N is required for amino acids, proteins and growth of the plant
- Crucial for chlorophyll and photosynthesis
- Commonly lost by leaching as nitrate doesn’t sorb to soil particles well
Describe the global distribution of N fertiliser production and use
China top producer and consumer
via the Harber-Bosch process
- Significant increase in use in India and USA
- No significant increase in Africa
= shows correlation with increasing yield in these areas
What is nitrification and denitrification?
Nitrification conversion of ammonium to nitrate
Denitrification conversion of nitrate to nitrogen
- Influences emission of N2O into the atmosphere
What are the negatives of N fertiliser application?
- Atmospheric N2O increase
- River fluxes
- greater leaching into rivers promoting the growth of algae and eutrophication, reducing O2 in the rivers - Increased tree mortality
- N toxicity, found that N deposition in terrestrial ecosystems affected tree survival. 3 species showed increased survivorship and were also AMF colonised, while 8 species showed decrease, and they were species that were EMF colonised.
- EMF facilitates uptake of organic N, increased N fertiliser is from inorganic N, resulting in nutrient imbalances that can alter the microbial community and result in reduced EMF benefit
How is NUE calculated? How can it be improved?
N uptake efficiency x N utilisation efficiency = yield of grain per unit N available
- Around 40% of the N fertiliser applied is actually taken up by cereals
- reaching N optimum, max concentration of N that generates the highest yield
Improvement
- enhanced by increasing uptake efficiency
- Transcriptional upregulation (overexpression of NGR5 leads to increased tiller number)
- Increase N assimilation by rhizobia
How can responsiveness to Nitrogen be visualised?
Looking at response to yield in different N conditions
- No effect will be 1:1 (middle), while positive effect above the line
What is a haplotype?
Set of closely linked genetic markers that are commonly inherited together
How have fertilisers been used in places such as India and China?
India
- Government subsidises the cost of fertilisers so commonly over-used
- Improvement by using colour charts to look at the need for N by the crop
China
- choice of fertiliser matters, ammonium nitrate releases the most GHG
- Proper management for fertiliser use leads to increased yield and income
How does increased access to a forest affect biodiversity?
Looking at 3km radius from a road or navegable river found that 50% of the Amazon rainforest is accessible
- lower number of animals near roads
- increased risk of roadkill
- fragmentation
Describe the types of organisms commonly in wildlife trade
Animals closer to extinction are more likely to be traded
- 25% of at risk vertebrates and 50% of at risk birds
Larger animals are more likely to be traded
Plants used for timber or decoration
What areas are the main exporters and importers of wildlife for trade?
Exporters
- Africa, S.America and S.E Asia
Importers
- China, N.America and Europe
What are the reasons behind hunting? (6)
- Subsistence farming (hunting for food or local trade)
- Cultural traditions
e.g. feathers and bones - Medicinal purposes
- Luxury meats
e.g. local delicacies, greater profit abroad - Trophy hunting
e.g. horns and skulls, rarity matters - Exotic pets
e.g. parrots and orchids
What are the direct consequences of wildlife hunting?
For species involved in wildlife trade there is a 62% of loss in their abundance
For subsistence farming, this results in a 50% loss in abundance
- Decline in elephants in central Africa, with their habitat overlapping with hunters
= 62% population decline in 9 years and 30% loss in geographical range
- Extinction of animals, such as a certain species of rhino (identified by DNA in dung piles)
- Increased risk of extinction e.g. of African teak due to over-logging
What are some mitigation strategies against hunting?
- Change in policies - reducing the value of ivory to reduce incentive for hunting
- Troops to monitor illegal hunting
- Training of rangers to help with conservation and prevention of illegal hunting
What is the anthropogenic Allee effect?
Where human perception of rarity of an animal drives exploitation, increasing endangerment (risk of extinction)
What are some indirect effects of hunting on the ecosystem?
Changes to seed dispersal
- Correlation between seed size and the size of the animal that can digest and spread the seed = resulting in a reduction of large seed dispersal that relies on certain animals. Seeds are dispersed shorter distances
- Above ground biomass decrease by around 3% and in some areas up to 37.8% (larger trees rely on large mammal dispersion)
Although - less animals eating seeds could increase seed survival
What arguments have been made for wildlife trade following COVID-19?
Following COVID-19 there has been an increase in calls to stop wildlife trade
Trading tactics written by World Animal Protection
- supports complete ban of wildlife trade in wet and wildlife markets
- suggests line needs to be made clearer to prevent illegal trade being passed as legal
- suggests that struggling communities are already being exploited for other reasons
Beyond banning
- suggest that banning is unreasonable and has profound effects on communities that rely on wildlife for livelihoods
- wet markets not just trading meats
- suggest a drive towards sustainable methods as banning will likely drive it further underground and make it harder to catch
- allowing hunting can promote conservation efforts as both is required for a sustainable business
Describe the extent of logging
400million hectares of tropical forests are in a timber state
Over half of the Congo forest has been disturbed, and around 1/4 of the Amazon has been modified
What is selective logging?
When only large marketable trees are cut down instead of many, non-profitable trees also
- this helps minimise overall biomass loss
How can the effect of logging on biodiversity be quantified? What are some studied effects?
Measuring species richness, species composition and interaction networks
e.g. increase in lianas due to greater presence of light, but reduce the survival of slow growing trees
- logging also increases the connections between species in logged forests
Fauna
- 75% of species richness is maintained in logged forests
How can logging be managed to reduce its effect on biodiversity?
- Market incentives and regulation
- promote controlled, sustainable logging - Reduced Impacted Logging (RIL)
- pre-requisite for timber certification which allows access to more markets
- requires plans for well built roads that minimise disruption and working with trained tree-fellers
= less of a damage and greater habitat recovery in a study (although only 4 sites were used) - Lower intensity logging
- underlogging to reduce impact, but likely will move logging location elsewhere - Land-sharing v land-sparing
- Sharing = lower intensity over the whole area
- Sparing = high intensity to meet yield, then preserve an area as primary
(vary between forests which one is better)
How can the impact of forest conversion be mitigated?
- Conservation purchases
- fund protection of forests, with the aim of balancing cost of protection and value of the forest. As a once-logged forest can drop significantly in value and a twice logged forest drops by value by 80% - Carbon enhancements and REDD+
- restoration of forests to accelerate carbon capture
- Reducing emissions from deforestation and forest degradation in developing countries (REDD+) developing countries benefit when they reduce their emission and reduce deforestation
How can changes to forest cover be measured?
LIDAR imaging - reduction in forest cover detected from planes
On the ground analysis
What are the two different types of mines?
Low volume High value
- diamonds and gold
- fly in fly out transport
- associated with small scale artisinal mining (can be illegal)
e.g. blood diamond
High volume Low value
- iron and copper
- carried out by large corporations
- 34% of these mines are within 10km of a protected area
- Indonesia has the greatest rate of forest conversion to mines
- Results in railway construction for transport
What are some secondary effects of mining?
- Expansion of road network and railway
- Expansion/ Development of settlements e.g. Geita township in Tanzania went from 30k to 120k people in 3 years
- Forest conversion to agriculture to feed workers
1 hectare of mine = 28 hectares deforested - Pollution
Describe how mines can result in the pollution of the environment
Improper disposal of tillings, which are commonly stored in a dam
Tillings = water mixed with chemicals and solutes produced from the mining process
- 13% of threatened species are at threat of mining pollution
Example: Samarco disaster, Brazil
- dam failure resulted in the toxic release of tailings that contaminated rivers and reached the Atlantic ocean. Killing 19 people and having a detrimental effect on the environment
What is the resource curse?
Countries with abundant resources are commonly more prone to corruption and civil unrest due to a weaker government
e.g. Simandou mound in Guinea where various companies and the government were investigated for corruption and bribery
What are the positives have having TNCs investing in mining?
- Creation of bio-diversity set aside to ‘cancel out the loss’
- have the money to - Poverty alleviation
- if corruption avoided - Reduction in mercury pollution
- from gold mining, costly but important - Improved transport
- they commonly invest in transport inks
Describe the mining efforts in Africa
Central Congo
- 10% of the mines are in protected areas, while another 13% are within 10km of protected areas
- 27% of mines are in Endemic Bird Areas
- Occurrence of desirable minerals doesn’t full overlap with the higher forest cover, but does sometimes overlap with oil
Chinese investment in African mining has increased by $75billion in 9years
- Increase in rail, with 240km running through the Congo rainforest
How can mining in forests be mitigated?
- Promote integrated land use planning
- minimising the effects of unsustainable settlement development - Strengthen government’s capacity to plan
- preventing corruption and generating legislation to prevent tailing disasters - Promote initiatives to offset impact
- Improve management of Artisinal mining
- introduction of mercury retorts that minimise mercury poisoning (reducing from 1.7kg of mercury released per 1kg of gold, down to 0.19kg of mercury released) - Carbon payments
- pay to prevent mining in other areas - Identify market choke points
- Post-mining reforestation
- in heavily mines areas this had little effect, but could be slightly improved by retaining the top soil - Recycling
- EU recycling nearly 40% of E-waste, also one of the top producers of e-waste alongside N.America and Australia/NZ
What is matching in offsetting, and how is it achieved?
Selection of an offsite that closely aligns with impacted site, based off ecological characteristics, function and value
- then compare whether the efforts to conserve the area is significant to compensate for the loss in biodiversity
e.g. protecting areas that would have been at risk from deforestation or biodiversity loss, instead of protecting an area that wouldn’t have been at risk.
e.g. Evaluation to compare that the area that is protected has benefitted significantly from the conservation effort
What is an example of a mine that has successfully offest the forest loss?
Ambatovy nickel-cobalt mine in Madagascar
- Offsetting involving averted loss offest - in which habitats are protected which otherwise would’ve been lost
- Statistical matching has been used to confirm No Net Loss of biodiversity
- Protected 4 sites which involved conservation activities to slow forest clearance, this includes educational programmes and reduction in deforestation
What are the 4 main ecological effects of roads?
- Habitat loss
- 95% of Amazonian deforestation occurs within 50km of a road - Road mortality
- species such as reptiles and amphibians are at high risk - Edge effects
- physical and chemical changes occurring adjacent to a road (pollution both noise and chemical) - Barrier effects/ fragmentation
- Gene flow restriction
- Dispersal translocations, some birds unable to return to their original habitat following translocation across a road
How can pollution effect ecosystem dynamics near a road?
Warmer near roads
- leads to increased transpiration of trees and increased water stress
Noise from roads
- changes bird behaviour, as evidenced by an experiment generating a phantom road that mimicked road sounds and found: 31% of birds avoided the area and there was an increase in vigilant behaviour, decrease in foraging behaviour, so lowering of body conditions
What are some over-arching mitigation methods against roads in the rainforest?
- Reducing wildlife mortality
- Increasing permeability (reducing fragmentation)
- Road planning
- minimise damage caused by roads
How can mortality from roads be reduced?
Barrier (fencing)
Road sings to make drivers aware
Setting speed limits
Windy roads to force slowing down
Road closures at certain times of the year, e.g. in Australia there is road closure for red carb migration
How can the effects of fragmentation be mitigated and reduced?
Over/Under pass (wildlife bridge)
Glide poles
Canopy connections (trees above roads)
What are some challenges with these methods for mitigation?
- Cost
- ecological bridge and overpasses are expensive - Enforcement
- enforcing no hunting, speed camera etc can be difficult with lots of area to cover and minimal people to monitor - Biodiversity cost
- windy roads disrupts more of the forest than a straight road - Effectiveness
- some methods aren’t effective and not all animals may use the under/over pass
How can the properties of the road alter their impact on biodiversity?
Wider roads - less likely for road kill as there is more reaction time and greater clearance. However, serves as a greater barrier and more animals may choose not to cross
Paved v un-paved - can change the movement of water in the system causing flooding downstream
What is an example of an area that has faced increased road building?
Congo basin
- Increased in road building and abandonment of raod with 44% being abandoned in 2018
- un- paved nature has allowed for some recovery
How has world trade of plants altered the pest/pathogen landscape?
Greater introduction of non-indigenous pests with no signs of saturation, there will likely be more species entering and establishing new territories
- The Rosace et al., 2023 study looked at data on first introductions and pathways for pest entry into the EU
Importance of the paper- to better understand the pathways of pest invasion to minimise additional introductions
Three separate stages 1. Entry 2. Establishment 3. Spread
CHALLENGE
- Pathogens may enter and spread by multiple pathways
- Historical data of occurrence is sparse
- Classification and delineation of species can be difficult
What are some notable plant pathogens? How have some affected human behaviour?
P.infestans causing late blight in potato
Dutch elm disease caused by fungus
Coffee leaf rust in Sri Lanka drove the development of tea drinking
Panama disease in bananas altering the variety of bananas eaten
What is the difference between endemic and emerging diseases?
Endemic - Routinely has an effect, commonly causing a large loss in yield. Controlled by chemicals and pesticides
Emerging diseases - Spread increases rapidly and is newly developing, commonly less is known about the behaviour. More important to look spatially at actively spreading areas
What are the different causes for the spread of pathogens?
- Long distance aerial dispersal
- e.g. Coffee leaf rust from Africa to Brazil
- pathogen needs to adapt resistance to dessication and UV - Trade
- P.infestans transferred from Mexico to Belgium
- regulation of material is important, however, it can take time (incubation) for symptoms to show - Climate change
- changes to seasonal patterning of growth of plants or wind spread of pathogen
e.g. Puccinia pathway that follows the seasonal changes in the growth of wheat in N.America
What facilitates the spread of disease in a field? (6)
- Monoculture
- Abundant sporulation
- Rapid disease cycles
- Clonal reproduction
- Few R genes
- Cryptic infection
What is the role of CABI?
Centre for Agriculture and Bioscience International
- Documents historical and current reports of first incidences of pests and pathogens in an area
- Important to get a sense of change over time and the trend in spread
What is the global trend in pathogen distribution?
Pole-ward shift
- Increase in beetle reports in more northern areas
(although countries at the equator may be slower at reporting)
- Warmer temperatures also promotes faster life cycles and rates of growth
- Climate may be a driver
How can linear models be used to model the expected number of pests?
Using a continuous response variable as a function of one or more predictor variables
- changing predictor variables to simulate different conditions and outcomes
e.g. Myanmar
- Modelling the effect of GDP and investment into R+D suggested that if more was invested and if Myanmar was richer then a greater number of pests would be detected
What variables can be used to detect whether global warming will affect the range and severity of disease?
Dynamic modelling of environmental effects includes changes in:
- Temperature, rainfall and CO2
Example Phoma Stem Canker
- monocyclic pathogen, economically important and commonly controlled by fungicides
IGNORES
- inoculum size, pathogen dispersal and repeated epidemic cycles
What is saturation when looking at pathogen spread? What is it dependent on?
Extent to which a pathogen is present in its potential distribution area
Number of countries infested/ Number of countries it could infest
- dependent on the presence of host crop/ plant
However, reports of host range may not be fully accurate and the pathogen could be able to infect a wider host range
What are some critiques of data used to measure and predict global changes in the distribution of pests and pathogens?
- grouping species and genera together when they may experience different changes (e.g. poleward or equatorial shift)
- data could be biased towards sampling location, time and effort. HICs more likely to detect earlier
- some pests/ pathogens when looking at spread may not be considered invasive due to lack of data on their distribution
Describe the global distribution of plant pests and pathogens (Bebber et al. 2014)
- 1% of CPP had higher than expected saturation due to infection of non-host non-crop species
- Pests had higher endemicity compared to pathogens
- Pest saturation in countries has increased linearly since 1950s
- Fungi and oomycetes have spread the most rapidly, despite having a more restricted host range
- Socioeconomic status and climate are good predictors for distribution
- lower saturation of important crops (wheat, rice, maize)that are grown at higher latitudes, likely due to split between two temperate regions
Describe the observed poleward shift in the presence of pests and pathogens (Bebber et al., 2013)
- Suggests a pole ward shift of 2.5km per year since 1960 of pests and pathogens
- Beetles and butterflies are showing poleward shift, while nematodes and viruses are showing a shift towards the equator
- Global warming likely increases insect herbivory in higher latitudes due to greater winter survival rates
Critiques - movement should be classed as displacement to overcome contrasting positive and negative changes in latitude
- movement of pests and pathogens may be due to anthropogenic causes and not climate change
- observational bias that higher GDP countries, commonly at higher latitudes would detect first BUT this wouldn’t bias towards the poleward shift
Describe the an example of modelling atmospheric transmission of pathogens
Chalara Ash Dieback
- fungal infection that is monocyclic
- first detected in Poland and then moved across Europe, first detected in the UK around Norfolk (assumption that spread was due to wind)
= sampling of the UK was carried out for presence and absence of the disease
Numeric Atmospheric Modelling Environment (NAME)
- monitors the pattern of wind and the potential spread of particles
Uses predictors such as size of particles, viability of spore
RESULT = greater deposition strength on the East coast of the UK, which matched with the pattern of disease distribution
What methods are used to mitigate the evolution of wheat stem rust?
Removal of Barberry which is commonly found in hedgerows and facilitates the sexual life cycle of the fungus
- This helps reduce the ability of the fungus to evolve and share genetic information
Commonly controlled by fungicides to prevent yield losses of around 50%
How can modelling suitability be used to predict the spread of a pathogen?
e.g. wheat Ug99 stem rust strain that emerged in Africa that was capable of overcoming strongest resistance sr31
Models were generated to calculate the probability of the strain invading India and Pakistan
Predictors - seasonal patterns, humidity and alignment with wheat growing periods
YEMEN - calculated as the area that requires high-surveillance as the pathogen could likely move from there to India easily (although social issues made this hard). Wind patterns coincides with crop growth that could’ve blown spores over
What is compartmental modelling?
Grouping different stages of infection into compartments such as infection, development of symptoms, infectivity and death
SECIR model
What is the reproduction number?
Average number of new infections that can occur from a single infected individual
Describe the importance of different dispersion kernels for analysing spatial dynamics. What are some critiques?
Exponential kernel - assumes that probability of dispersal decreases exponentially with distance. (localised spread)
Cauchy kernel - assumes that infection doesn’t decrease with increased distance (common for plant diseases)
Critiques
- Assumes that distance is the only factor, however, environmental factors such as wind may also play an effect as to how far certain pathogens spread
- Direction of spread may depend on which way the plant is ‘facing’ important to include a preferential angle of spread
How can models be fitted to data?
Approximate Bayesian Computing
- runs many models and only accepts those that are within a certain tolerance of the data
Issues
- setting the tolerance range
- actual meaning of matching of the data with the model, as it may vary when looking at different parameters such as how well the model fits the increase in disease or the spatial patterning of disease (may not match on all fronts, but then which is more important?)
What are some critiques for compartmental modelling of disease dynamics?
- Assumes constant infection rate
- Simplication of complex interactions that disease and hosts may have
- Assumes a homogenous population where susceptibility is equal
- lack of feedback and temporal dynamics that may alter certain rates
What is incidence?
Proportion of the population that is infected
What is a beta-binomial distribution?
Distribution where the probability of success at each trial is not fixed, but random
More flexible model that represents spatial patterning
Not really relevant for invading pathogens where there isn’t enough data
How is sampling effort dependent on incidence?
Probability of finding disease = 1- chance of not finding
- For a pathogen with lower incidence, more sampling is required to detect it
What is the rule of three and what are some problems associated with it?
If there is no detection in N amount of samples, then probability of incidence is 3/N
- With a confidence interval of 95%
PROBLEMS
- Assumes that disease is constant through time and space, which is not true for an invading pathogen with a spatial pattern
How is mean detection incidence calculated?
epidemic growth rate/ sampling rate
- so faster growth rate = incidence is greater when detected
- higher sampling rate means that when the disease is detected, mean incidence is likely to be lower
For slow epidemic growths how can a sampling programme be designed? How would this struggle for a fast-growing epidemic?
Slow growing - straight line for sample size (N) on x axis and sampling interval, which correlates to different incidences
Meaning that the same incidence can be found when sampling 10 plants every 20 days or 20 plants every 40 days
- For fast-growing epidemic the relationship is likely to curve and increasing the interval will lead an increase in incidence
What is Parnell’s rule of thumb sampling?
Used for Huanglongbing (bacteria)
- requires an estimate of epidemic growth rate
- good for diseases with low incidences and where sampling effort can be large
What factors are taken into account when looking at where to sample?
Single known sources - NAME (Numerical Atmospheric-dispersion Modelling Environment)
Multiple sources = look at the risk
Consequences (host density) x probability (usually distance)
How can sampling be done to include risk?
Weighted random selection or
Multiplier effect to focus on higher risk sites
How can sampling start sites differ?
Depends on what you want to know
- Sampling for greatest disease abundance in an area
- Sampling for coverage of disease (maximising chance of finding)
What is simulated annealing?
Optimisation algorithm
- generates iterations to find the best sites to sample (sometimes overkill)
- Requires full disease model
As the algorithm proceeds, it gradually reduces the probability of accepting worse solutions to focus on areas around better solutions.
What is the importance of looking at sensitivity?
Patterns of sampling may change based on success from sampling
Low sensitivity drives sampling towards high risk and fewer sites
High sensitivity means the sampling effort can be spread more widely
What is an example of trying to find the optimal cull radius for a pathogen?
Citrus Canker in Florida
- ranged from 125ft radius to 1900ft, scrapped in 2006
Describe the relationship between cull radius and epidemic impact
With increasing cull radius there is a reduction in epidemic impact which reaches an optimum
- After this there is a steady increase in epidemic impact as the cull radius is large
What are some negatives of a constant cull radius?
- May miss trees that are just on the edge of the radius but may pose a high risk
- May miss trees could have high R0
- When radius is very large, can be hard to explain cause as likelihood of infection isn’t constant
What is the risk based control? Suggest some critiques
Inclusion of risk (probability that host is infected x rate of infection
- including R0 and spatial distribution of susceptible hosts
CRITIQUE
- doesn’t really include epidemiological processes, and so hard to know when the pathogen will be present, which may result in ineffective sampling
How can a variable radius control be generated?
Static model that depends on R0
- so increasing R0 increases radius
Why is risk based modelling better than variable and constant radius control? What some issues with risk-based modelling?
- includes pre-emptive culling (may be hard to except)
- modelling suggests it leads to lower epidemic size
- when changes in parameters occurs, risk-based model responds better and faster
ISSUES - requires good data, if not good them could lead to more economic damage than good
Describe Sudden oak death as an example of controlling an epidemic
Phytophthora ramorum - generalist that can infect many species
- modelling suggesting that no extent of culling can have a significant effect on epidemic size
MODEL AREA, BUDGET AND YEAR
- suggests that in 2005 if 50km was controlled then that could’ve stopped the epidemic
- development of epidemic size is curving away from a controllable level
Why is it important to consider budget and culling area in control?
- Linking area to economic cost is important to prevent excessive loss
- Important to regulate budget, suggesting that spending a lot early on (larger radius) is better instead of doing not enough’ over time
Where in the infection spread should be managed/ culled?
Treating infection front is better than within the infected population
- middle areas has no significant benefit
What model/ algorithm monitors the effect of waiting before employing control methods?
Control Fast algorithm
- simulates the outbreak to optimise when the best control time is to reduce the Normalised cost and have the greatest effect
- assumes that as time goes on more is known about the pathogen for better control as the best cull radius depends on the growth rate of the spread
Normalised cost - cost of removal, of waiting etc.
= cost of control, epidemic size and change in R0 (based off rate of learning)
What are some challenges in modelling plant diseases?
- Modelling plant host
- temporal changes in host availability based on seasonal changes
- changes to their spatial distribution
- multi-host pathogens
- effect on crop yield can be difficult - Modelling the plant pathogen
- sparse data on biological processes e.g. methods of spread
- interactions and overlap between natural and artificial spread
- vector preference
- multiple infections that can increase susceptibility
- time-varying effect between infection, symptoms and infectiousness - Modelling control
- efficiency of detection
- economic viability of control of detection
- applicability of models in policies
Parsimony - simplest model used to avoid spending money and effort on other mechanisms
What aspects of a model need to be challenged?
- Data - representative? accurate?
- Mechanistic or correlation model - biological processes, feedback and interactions?
- Whether rates are constant over time
- Whether dispersal is consistent in all directions
- Climate models commonly ignore biotic factors
Describe Mastin et al., 2020’s optimisation of risk-based surveillance. Include the need for another strategy and the overall outcome
Optimisation
- Includes the role of epidemiological processes in the spread of the pathogen and how this can be used to find surveillance sites that maximise the probability of disease detection
Outcome
- Optimised using Simulated Annealing and was found to be better than targeted surveillance strategies, by generating risk clusters, which allow for sampling in other areas
- Independent of economic factors to highlight the role of non-economic factors in affecting surveillance performance (such as epidemiological processes)
Lecture 20
Describe new techniques to detect Xylella fastidiosa infection
X. fastidiosa, broad geographical and host range, infections in some hosts can be symptom-less, spread can be via sap-sucking insects and so hard to control
Techniques
Carried out on olive trees in Italy
- Airborne imaging spectroscopy and Thermography
- Analysing changes in anthocyanin content, and pheophytin levels due to the effect of the pathogen on pigments and other plant functional traits
- Found that this form of imaging can detect previsual infections, which were later confirmed with qPCR
- Time aspect of the experiment also found that 61% of the initially classed ‘false-positive’ detections (classed due to a lack of symptoms) later developed visual symptoms within the year
What is insectageddon? What is some evidence that supports this?
The observed decrease in the abundance of insects
1. Ecological armageddon in Germany
- 76% decline in insect biomass over 27years
2. Grassland areas in Germany
- 67% decline in insect biomass, and decline in species number
3. Loquillo forest, Puerto Rico
- 60-fold decrease in the presence of ground arthropods over 36 years
- Although this may have followed an increase as a Hurricane hit prior which levelled trees providing habitat
4. Lepidoptera in the UK
- abundance of large moths has decline by 30%
- abundance of butterflies in areas which they are known to be found also decreased
- saw an increase in abundance and then decline, overall decline
What is occupancy?
Probability of presence
What are critiques with the observed insectageddon phenomenon?
- Starting baseline may be off
- studies that included data from a few years prior found no significant decrease in the abundance
- measurements taken after the ban of DDT insecticide could be showing the recovering population, so baseline is higher - Insect populations may vary anyway
- Sampling bias
- with butterflies areas that were known to have butterflies were sampled, and random sampling was not carried out - Ecological complexity
- interactions with predators, prey and insecticides could be driving cause for change instead of the climate - Estimate that there are 7million arthropod species
- not enough is known to properly characterise perhaps
What meta-analysis approach can be used to combine and evaluate data from different sources? What does it show about arthropod data?
Fisher z score to generate a forest plot
- abundance and biomass suggested to be increasing in freshwater systems but decreasing in terrestrial systems
(this could be due to improvement in freshwater quality)
What are the three different types of biodiversity data?
Distribution data
Abundance data
Species richness data
What might be driving insect decline?
- Climate change
- Species at the southern edge suggested to be moving northwards = decline in geographical range - Insecticides
- neonicotinoids banned in Europe as it was shown to cause bee deaths and 60% drop in queen numbers
- Some studies have suggested they don’t have that severe of an effect but important to look at funding and the amount of insecticide used - Land use change
- changes in edge density and habitat amount, found that increasing edge density to increase hedgerows has a positive effect
How can drivers of insect decline interact?
Climate change moving species northwards to where developed countries may be using more insecticides, further narrowing the geographical range
Concentration of species into edges can increase disease burden and as a result have a negative effect on abundance
Why is insect decline important to look at?
- Pollination- 75% of major food crops and 88% of wild plant species rely on pollination
- Pest regulation by natural enemies
- Protein provision, especially for birds
- Provide important ecosystem services and important in the food web
What are the stats for crops and land that is used for food?
15 plant and 8 animals species provide 90% of food
1/3 of the world’s land area is used for crop production
Increased temperatures may lead to a reduction in yields by 1/3
35% of the world’s crop production is dependent on pollinators
What are the Aichi biodiversity targets?
Set of 20 targets generated in 2010 in Aichi, Japan aimed at targeting biodiversity loss by including 5 overarching themes
- targeting the causes, minimising the loss, increasing biodiversity status and the benefit from biodiversity
What are the 5 direct drivers of biodiversity loss?
- Changing land and sea use
- Direct exploitation
- Climate change
- Pollution
- Invasive non-native species (generating competition or acting as pathogens)
How can ecosystem structure (an EBV) be measured?
Measuring changes in forest or coral cover, and amount of wetlands
- most seem to show a decline except maybe vegetation cover and biomass
How can ecosystem function (an EBV) be measured?
Measured by looking at the carbon and water in systems
- eg. NPP and amount of C sequestration
- 60% of the atmospheric C released by fossil fuel burning is captured by nature’s carbon sink
How is community composition (an EBV) measured?
Changes in species abundance and richness, additionally looking at the change in the number of invasive/ alien species
- Suggests an increase in non-native species that alter community composition and interactions
Describe the type of data that is available for measuring community composition?
- Biased towards marine environments, recorded from shipping vessels that also follow a very direct line
- Data from forests show that even with fragmented forests
- Shows a decrease in beta diversity, suggesting biotic homogenisation where communities are becoming more similar to one another
What is the Biodiversity Intactness Index (BII)?
Comparison between species abundance between different areas that have undergone different land use changes and comparing how much the areas differ to a pristine untouched reference ecosystem
- Many areas show 60% intactness
- Parts of the Amazon, Alaska and Siberia show more than 95% intactness
What are the different variables that are used to classify animals in the IUCN red list? What biases may arise from this?
- Population size
- Geographic range
- Number of mature individuals
- Probability of extinction
Biases
- Data availability bias (mammals and birds more likely to be re-assessed)
- Taxonomic bias (vertebrates more likely to be analysed than insects etc)
- Geographic bias (areas with greater sampling and monitoring effort will have more accurate information)
- Difficulty in finding and classifying individuals e.g. identification of mature individuals
What are some biases in species population data?
- Bias towards endangered species
- Increasing in the number of records for species presumed to be close to extinction due to greater surveying effort - Bias towards species that are more abundant
- Easier to record and can alter the perception of extinction risk. By comparing to large populations instead of random sampling, different trends are found - Unrepresentative baselines
- 1976 was a hot year that led to an increase in butterflies, however, if this was set as a baseline then a decline would be perceived
- Pre-fur trade shows that there has been a decline in abundance, however, setting a baseline post 1970 and post trade can suggest no change - Uneven geographic coverage
- Greater coverage and historic data in EU and Americas compared to areas such as Africa - Uneven recorder effort
- Greater publications in more developed areas, surveillance effort accounting for presence but never really absence of a species
What is the living plant index?
Measure of the world’s biological diversity based on population trends of vertebrates in terrestrial and marine habitats
What are some improvements that can be made to reduce bias?
- Compare sources
- Systematic monitoring
- Randomise which locations are chosen
- Cut off the first 5 years to find a representative baseline
- removes the variation found, but depends on the variability
Why are models important in generating policies surrounding biodiversity?
- Quantitative models are important for depicting ecological interactions
- e.g. species distribution models (SDMs) to predict the movement of species - Help generate projections of the impact of policies
- Also important for reviewing, formulating and implementing policies
e.g. Nicholson et al., 2019 criticises the use of percentage targets in Aichi 11 that don’t hold much meaning when quantifying biodiversity. As seen by studies that show that effective management is more important than volume management - Also important for evaluating counterfactuals which are events that would have occurred if policies had not been implemented
- PRIORITISING - generate strategy to prioritise and target areas most at risk
What are the post-2020 Global Diversity framework goals centred around biodiversity?
- Protected areas should expand and cover 30% of the world by 2030
- 30% must include areas classed as being relevant for biodiversity
- Ensuring that plans and aims are scalable at local and global scales
- Ensure that social and economical factors aren’t compromised
What are 5 examples of legally binding treaties?
- Ramsar convention on wetland conservation
- Convention on International Trade in Endangered Species - targeting wildlife trade
- Convention on the law of the sea (LOSC)
- Framework Convention on Climate change (UNFCCC)
- supports response to to the threat of climate change - Convention on Biological Diversity
- Cartagena safe use of GMOs
- Nagoya ownership of genetic material, inclusivity of research
What are international treaties?
Formal agreement between states governed by international law
What is Aichi target 11 and Aichi target 7?
11 - Increase the percentage of protected terrestrial (17%) and coastal (10%) areas by 2020
7 - Sustainable management of agriculture and forestry to ensure conservation of biodiversity
What are the success and challenges associated with Aichi target 11?
Success
- Increase in protection of terrestrial land in countries such as Republic of Congo, Bulgaria, Venezuela and Chile
- Greater global awareness of biodiversity
- More data on biodiversity
Challenges
- Representativeness of the areas as a measure of biodiversity (Quantity over Quality)
- Connectivity gaps, and fragmentation of protection
- Equity and inclusion of indigenous groups and locals
- 20% of threatened vertebrate species are not covered by any protect area
- Ecological representative = for species with a larger range a smaller portion needs to be protected to be significant
- In the Atlantic forests in southern Brazil 59 endemic species fall outside of the protected zone. For another 139 endemic species less than 5% of their range was protected
What are some was Aichi target 7 can be met?
- Retention of areas of primary forest
- Organic farming
- lack of pesticide use can be beneficial, however, requires 20% more land to generate the same amount of yield so may not be better - Native habitat in Working Landscapes (NWL)
- Garibaldi et al., 2019 argued that 20% of the NWL needs to be conserved to retain ecosystem function
- redesigning agriculture systems to include native biodiversity and help with pollinator abundance and preventing the leaching of nutrients
What evidence is there that by introducing native patches and increasing biodiversity, there can be a positive effect on yield?
In some cases conversion of land to native vegetation can increase the yield of the whole area, but there is a balance between greatest yield increase and amount of conversion.
- Increasing conversion to vegetation patch will reduce the area of land that produces yield
1. If the vegetation patch provides no yield benefit then there is a yield loss, in some cases it may be more detrimental e.g. conversion to native in India in rice fields significantly decreased yield
2. If conversion is beneficial this can lead to a yield increase, e.g. flower strip in peanut field increased the total yield of the whole patch, accounting for the area that was converted
e.g. tree islands in oil palm farms increased the yield of surrounding trees
What is the biodiversity mitigation hierarchy?
- Avoid problem fro happening
- Minimise the damage
- Rehabilitate to reduce impact
- Offset to aim for No Net loss
- Additional Conservation Actions for biodiversity gain
What are the conditions for No Net loss?
No Net loss - biodiversity loss is offset by biodiversity gain elsewhere
1. Losses and gains are COMPARABLE in type and amount
- Extinction, protecting a different type of environment, or reforestation is NOT comparable
2. Biodiversity gains are ADDITIONAL
- If conservation methods weren’t implemented in that are then the are would have faced decline, improvement is significant
3. Biodiversity gains are LASTING
- Sustainable and long-lasting
How can offsetability of an area be assessed?
- Vulnerability or concern
- How at risk an area is. More at risk = harder to offset - Likelihood of offset success
- Areas with greater concern require strategies with higher likelihood of success to for offset to be reasonable
Describe the offset success of the Ambatovy nickel mine in Madagascar
Mine opened in 2010s and had a target of No Net Loss
- 4 areas were included in the offset
- Habitat surrounding the area was restored
- Effectiveness was measured against similar sites by matching
Challenges and criticism
- Ankerana forest that is protected isn’t ecological identical to the environment where the mine is present as Madagascar also has a lot of endemic species
- Temporal lag between significant biodiversity gain and loss
- Social conflict, local communities expressed concern over restricted access to forests
