Ecology and Evolution in the Anthropocene Flashcards
1
Q
What are the disciplines of ecology and evolution focused on?
A
Understanding the distribution, abundance, and inter-relationships between species.
2
Q
Eco-evolutionary feedbacks require what?
A
populations that alter their environment and that these alterations feedback to influence the subsequent evolutionary change.
3
Q
Who came up with the idea of evolutionary ecology, and what publication was it in?
A
G. Evelyn Hutchinson came up with the idea in a publication called “The ecological theatre and an evolutionary play”.
4
Q
What is the fundamental niche?
A
The full range of environental conditions that a viable population of species can occupy and use, without any other limiting factors present which could constrain the population.
5
Q
What is the realised niche?
A
The range of environmental conditions that a viable population of species can occupy and use, when constrained by limiting factors.
6
Q
What did Hutchinson define a niche as in 1957?
A
A region in a multidimensional space of environmental factors that affect a species.
7
Q
Why is Hutchinson’s definition of a niche now questioned?
A
Because the measurement of niche volume is subjective, some important dimensions aren’t known, niches change in the life cycle, and niches change from one region to another.
8
Q
What does the climate envelope approach use?
A
It uses climate variables to make spatial predictions of environmental suitability for a species.
9
Q
What is one approach to climate envelope modelling?
A
One approach is to sample climate data for species occurance/absence, then create a prediction map based on contemporary climate suitability, and these can then be further extrapolated under future climates.
10
Q
What is one of the limitations of climate envelopes and how do we overcome the issue?
A
One limitation is measurement, which is a matter of is it not there, or have we not looked enough. To overcome this, there needs to be incorporation of traditional ecological knowledge and using this in models.
11
Q
What are two important things to consider in species distribution?
A
Physiological effects, which can be affected by plasticity and acclimatization, and biotic effects, so species interactions.
12
Q
What do fundamental niche models describe?
A
The distribution/abundance of a species in the absence of limiting factors. Population-level processes link abundance and distribution to environments.
13
Q
What do realised niche models describe?
A
The distribution/abundance of a species in the presence of limiting factors, and it introduces the concept of limiting similarity.
14
Q
Fitness is a _______ function of distance from the optimum.
A
Gaussian
15
Q
There is ______ selection towards the current phenotypic optimum.
A
Stabilising
16
Q
What does it mean by a quantitative trait?
A
It means that many genes determine the trait.
17
Q
What is a positive selection gradient?
A
It is where relative fitness is low in the current population and highest for those individuals with the largest trait value.
18
Q
The hereditable trait variation is what?
A
Additative
19
Q
Phenotype = ?
A
genotype + environment
20
Q
Phenotypic variation = ?
A
genetic variation + environmental variation + (GxE)
21
Q
What is additive genetic variance?
A
The average effects of alleles at individual loci contributing to the trait.
22
Q
What does additive genetic variance exclude?
A
Genetic interactions of dominance variance and epistasis.
23
Q
What do evolutionary responses depend on?
A
The amount of genetic variation and the strength of selection.
24
Q
What maximises additive genetic variance?
A
High mutation rate, larger population size, more balanced sex ratio, and more outbreeding.
25
What maximises the selection gradient?
Bigger change in the environment, and lower ecological tolerance.
26
What's one way to work out if something is genetic or phenotypic plasticity?
One way is to make hybrids and if the hybrids are an intermediate, it's probably genetic plasticity.
27
Describe what a moving optima in a population looks like.
The population adapts to the change, but it is lagging behind and it catches up once the environment stops changing, but there might be populations that can't adapt quickly and these gradually decline and go extinct.
28
What is the concept of evolutionary rescue?
If a population is trying to catch up to a moving optima, there will be population decline, and so genetic variation is reduced. The concept is where there is a possibility for new mutations to arise and save a whole population.
29
Selection on correlated traits will affect a response in what?
The focal trait.
30
In reality, traits are not what?
Strictly independent.
31
What are genetic correlations?
Where some of the same genes influence variation in multiple traits, and this can be represented as genetic covariance between 2 traits.
32
Shorter scale fluctuations in environments might select for what?
Phenotypic plasticity.
33
What is an example of phenotypic plasticity?
Egg laying in Great tits in Wytham Woods, where they match the laying date to the yearly variation.
34
What is genetic assimilation and what can it limit?
When a plastic change becomes genetically based over time, it can limit genetic responses by weakening selection pressure on genetic changes.
35
Life history strategies can be thought of in terms of what?
Key events in the life of an organism.
36
What would one expect to see regarding the lifespan of organisms in rapidly changing environments?
For it to be shorter.
37
How do you get survival in a matrix?
You get the sum of the columns.
37
No organism can excel in what life histroy traits?
Development, reproduction, and survival.
38
What are the predictions under an independently, identically distributed enviroment?
Shorter lifespans, faster senescence, body fluctuations/smaller size, earlier reproduction, frequency of reproduction, more offspring per reproductive event, and less parental care.
39
What is a key prediction for life history theory?
Random variation in environmental conditions select for annual species.
40
Animals and plants tend to sit themsleves along what 2 axis?
fast-slow continuum, and the reproductive strategies.
41
Symbiosis doesn't mean what?
That both species benefit.
42
What varies inversely across abiotic stress gradients?
The frequency of facilitative and competitive interactions.
43
What is the competitive exclusion principle?
That no two species can coexist if they share the exact same niche.
44
Quantifying the success of any species requires knowing what?
Its growth rate, r.
45
What do population sizes always move towards?
Equilibrium
46
What are zero growth isoclines?
Where there is no growth and it is in equilibrium.
47
What results in coexisting?
High intraspecific competition and low interspecific competion.
48
What are some important aspects that the Lotka-Volterra model doesn't include?
More than 2 species interactions, individual heterogeneity, and environmental stochasticity.
49
What are alien/non-native species?
Species that have been introduced to new regions by humans.
50
What are invasive alien/non-native species?
A subset of alien species that are known to have established and spread with negative impacts on nature, and they can also have negative impacts on humans.
51
What are native species?
Species inhabiting its natural range including shifting its range, without human involvement.
52
What is propagule pressure?
The number of individuals introduced to a new location.
53
What features increase the chance of survival and establishment of invasive alien species?
Increasing propagule size and number, increasing number of invasive locations, and the health of individuals.
54
What are specific characteristics of invasive alien species?
Characteristics include: being capable of asexual reproduction as well as sexual reproduction, rapid body growth, early sexual maturity, high reproductive rate, high dispersal ability, generalist diet, phenotypic plasticity, tolerant to a broad range of environmental conditions, and synanthropy.
55
What is one of the 5 major drivers of biodiversity loss?
Invasive alien species.
56
Where is the impact of invasive species highly felt?
On islands.
57
What are biological invasions?
The process involving the intentional or unintentional transport or movement of a species outside its natural range by human activities and its introduction to new regions, where it may become established and spread.
58
What is the release in nature pathway of alien species introduction?
The intentional introduction of live alien organisms for the purpose of human use in the natural environment.
59
What is the escape from confinement pathway of alien species introduction?
The movement of invasive species from confienement into the environment. Through this pathway, organsism were purposefully imported or otherwise transported to confiement, but then escaped.
60
What is the transport-contaminent pathway of alien species introduction?
The unintentional movement of live organisms as contaminant of a commodity that is intentionally transferred through international trade, development assistance, or emergency relief.
61
What is the transport-stowaway pathway of alien species introduction?
The moving of live organisms attatched to transporting vassels and associated equiptment and media. The physical means of transport-stoawat include various conveyances, ballast water and sediments, biofueling of ships, boats and offshore gas pplatforms and other water vessels, dredging, angling or fishing equiptment, civil aviation, sea and air containers.
62
Introduction of an alien species can result in what?
Ecosystem modification.
63
What is a corridor pathway?
The movement of alien organisms into a new region following the construction of transport infrastructure without which spread would not have occured.
64
What is an unaided pathway?
The secondary natural dispersal of invasive alien species that have been introduced by means of foregoing pathways.
65
What pathways have played a major role in plant and vertebrate introductions?
Intentional introduction pathways, like release and escape.
66
What pathways have played a major role in invertabrate, fungi and algal introductions?
Unintentional introduction pathways, like contaminant and stowaway.
67
What are examples of invasive species?
Free-ranging domestic cats, parakeets in Seville forcing out greater noctule bats, mice on Gough Island attacking native sea birds, mainland lizards attacking island lizards on islands, lionfish, cane toads.
68
What happens if there is eradication of grazers like goats and rabbits?
There can be mass growth of plants.
69
What examples exist of hybridisation of native and alien species?
Wild cats and domestic cats hybridising is a new phenomenon, and there have been American mink and European mink hybridisation.
70
What do the effects of introduced species involve?
Complex chains of interconnected interactions.
71
What's an example of the complex interactions between an invasive plant and its ecosystem?
Fire trees, which are nitrogen-fixing are perfect conditions for invasive species, and the fires promote earthworm poulations, and then the introduced pigs and songbirds disperse the seeds.
72
What impacts do numerous introduced species have on native species?
Both direct and indirect impacts.
73
What are the major pathways by which habitat modification can interact with species invasion to increase the total impact on native species?
An interaction chain effect, and an interaction modification effect.
74
What is an interaction chain effect?
Where the total invasive impact on native species is increased by the indirect effect of habitat modification on invader abundance, but the per capita invader impact ramains constant at all levels of habitat modification.
75
What is an interaction modification effect?
Where the total invasive impact is dependent not only on invasive abundance but also on the degree to which habitat modification alters ecological interactions between invasive and native species.
76
What increases the vulnerability of natural ecosystems and alter processes that cause natural disturbance of landscapes?
Land-use and sea-use changes
77
What may lead to the increase in establishment and spread of invasive alien species in disurbed habitats and in nearly natural habitats?
Climate change, along with the continued intensification and expansion of land-use change.
78
Why is the magnitude of the future threat from invasive alien species difficult to predict?
Because of complex interactions and feedback among direst and indirect drivers of change in nature.
79
What are the best things to do about invasive species?
Prevention, early detection, and control/eradication.
80
What can we do to prevent invasive species spreading?
It can be achieved through pathway management, sustained and adequate funding, monitoring, quarantine, inspection facilities, and scientific cooperation.
81
What is an effective option for the eradication invasive alien species?
Containment and control can be highly effecitve, but in general, eradication has been successful recently.
82
What is necessary for effective prevention measures?
Sustained and adequate funding, capacity building, technical and scientific cooperation, transfer of technology, and suitable facilities.
83
Where has the eradication of invasive species been especially successful?
In small and slow-spreading populations of invasive alien species, even more in isolated ecosystems.
84
What can be an effective option for invasive alien species that can't be eradicated?
Containment and control.
85
By 2050, the total number of alien species globally is expected to be what?
About 36% higher than it was in 2005.
86
What is the definition of renewable resources?
Having the ability to replenish within a human lifetime.
87
What is economic rent?
Income derived from ownership or control over a limited asset or resource, without an expenditure or effort by the resource holder.
88
What is opportunity cost?
The value of the best alternative (forgone) choice.
89
What is the size or population of a harvested ecological system referred to as?
It is referred to as stock and uses the notation x.
90
What are open-access goods?
Rivalrous, non-excludable goods.
91
What are examples of ecological systems, the intrinsic properties that define how they change over time and the extrinsic properties affecting how they change over time?
Ecological system - fish stock, forest, groundwater basin.
Intrinsic factors - birth, mortality, immigration, immigration, recharge rates.
Extrinsic factors - climate, disease.
92
What are examples of social systems and the intrinsic properties that defines how they interact with the resource over time?
Social system - human actors that obtain benefit from resources over time, either as suppliers or consumers of the resource.
Intrinsic properties - how much time there is to harvest, how easy it is to harvest, the opportunity costs of time/capital.
93
Where is the maximum growth on a population growth graph?
It is on the increasing part of the line.
94
What is the total allowable catch?
How many fish of a given species can be caught over a specified time period.
95
What are two ways of estimating the total allowable catch?
Using the proportion of estimated total stock size, or basing it on previous catch levels.
96
How can fisheries achieve sustainable yield?
By removing the same number of fish that are added each year.
97
What is effort in terms of fisheries?
A measure of how hard people are working to fish. This includes, the number of boats, number of hooks, size of nets, and number of fishing days.
98
What is the relation between population size and effort?
They are inversely related.
99
What is maximum economic yield?
The sustainable catch or effort level that creates the largest difference between total revenues and the total costs of fishing.
100
When starting in a new unharvested population, what happens?
The stock population size is near the carrying capacity and so there will be a stock size decrease/
101
Does maximum sustainable yield or maximum economic yield have more resilience to the system?
maximum economic yield
102
What is the dynamic optimisation problem?
It is the problem is how much of the resource should be harvested today.
103
Dynamic have a stock or state variable that requires what?
A difference or differential equation to describe its evolution over time.
104
What is the solution to the dynamic optimisation problem?
The answer is to use a time path that indicates the optimal amount to be harvested in each period or a policy indicating how harvest depends on the size of the resource stock.
105
What do dynamic optimisation problems typically maximise and what are they subject to?
The maximise some measure of net economic value over a future time horizon, and it is subject to the dynamics of the harvested resource and any relevant constraints.
106
What do discount rates reflect?
They reflect society's rate of time preference and they are usually positive as people value present opportunities more than future ones.
107
What is the escapement model and what assumptions are made?
The escapement model is used where fisheries are managed to ensure that some number of fish escape harvest. However, the big assumption made with this idea is that we can precisely measure fish stock and harvest.
108
What are further applications of a bioeconomic model for fisheries?
Stochastic evolution of the fish stock, other sources of fish mortality, size-selective fisheries, and to think about different species interactions.
109
What is an example of species interactions involving fisheries?
An example is where fishermen are harvesting cod, and then the grey seals are getting fish from the nets, leaving these fish being unsellable. Grey seals have been protected and have done really well and recovered well, but it means that managing the seals impact on fisheries is now important.
110
How can size-selective fisheries be made?
They can be made by gear modifications, like holes in nets for smaller fish, and using landing regulations, like different hooks.
111
What happens if we only catch one size in size-selective fisheries?
Catching only small fish is possible as they have a lower reproductive rate than big fish. However, catching only big fish allows the smaller fish to have the opportunity mate.
112
How can the main selection pressures on life on earth be grouped?
They can be grouped as biotic and abiotic.
113
What do abiotic selection pressures include?
The physical environment changing over a range of scales.
114
What do biotic selection pressures include?
Strong interactions between organisms, reciprocal selection pressures, and relentless change.
115
What is the law of constant extinction?
The idea that species don't get better adapted over time, and extinction risk is independent of the age of the taxa.
116
What can the Court Jester paradigm predict?
It can predict evolutionary responses by considering how each species in parallel adapts to environmental change.
117
What is the Red Queen Response to biotic pressures?
It is where the response of each species if affected by interactions with other species and their responses.
118
What is coevolution?
The reciprocal evolutionary change in interacting species, owing to natural selection imposed by each in response to genetic changes in the other.
119
Coevolution dynamics depend on what?
The direction and strength of fitness, but also the specificity of the interactions.
120
What can competition lead to?
Trait divergence, character displacement and niche partitioning.
121
Competition can do what when living in communities and adapting to environmental changes?
It can inhibit evolution if other species already have suitable traits for new conditions, or it could amplify evolution if coevolution enables or forces competitors to adapt to new niches.
122
How can you test ideas about communities and adaptation to environmental changes?
You can do evolution experiments with bacteria, building simplified communities with different conditions which are then tracked.
123
How do you experimentally show that two bacteria evolved differently in the presence of other species?
You look at the trade-off between adapting in monoculture vs. adapting in polycultures in bacteria, with the isolates evolving in polyculture not growing as well as in monocultures.
124
Where did the partitioning of food resources evolve more?
In polycultures.
125
What did coevolved polyculture have as a result of partitioning?
Enhanced ecosystem functioning.
126
What can give clues about coevolution?
Congruent phylogenies of associated species.
127
What does it mean if there is high congruence in congruent phylogenies and why is this seen?
Mutualism is seen where there is high congruence and this is due to the vertical transmission.
128
What is seen in less congruent phylogenies and why?
Parasitism might be seen in less congruent phylogenies as this allows for jumping of hosts due to horizontal transmission.
129
Parasites and pathogens are what?
Ubiquitous, under strong selection to infect hosts, small relative to hosts, have high mutation rates, large population sizes, short generation times, and can impose a large fitness cost.
130
Host-pathogen coevolution speeds up what?
Molecular evolution.
131
What are the 2 major genetic models of coevolution, and what do they look like?
The two major genetic models of coevolution are the escalating dynamics/arms-race (two close together sigmoidal curves repeated along a graph), and fluctuating dynamics/Red Queen (like DNA helices, two wavy lines that cross over).
132
What implications are there for the current host if there is an escalating dynamic?
The current host is most resistant to past parasites whereas the future parasite is most infectious to the current host.
133
What are the implications for the current host if there are fluctuating dynamics?
The current host is best at resisting the current parasite, or the current parasite is best at infecting the current host.
134
What do the different patterns for different phage types show?
They show that the revolutionary outcomes depend a little bit on the species identity, but it can be unpredictable.
135
What can we apply coevolutionary theory to and why?
We can apply it to agricultural pathogens and this is possible as there has been major transformation of biomes into species-poor moncultures.
136
How can farmers control crop pests and diseases?
By using pesticides, focusing on crop hygiene, doing crop rotations and getting new resistant crop varieties.
137
Reducing crop losses from pests reduces and increases what?
It reduces the land area needed to grow food and increases food security.
138
What does plant breeding aim to do?
It aims to enhance resistance via a single major gene or multiple genes, but this selects counter-measures to store the infectivity in the pathogen.
139
What in crops is like coevolutionary cycles?
Boom-bust cycles with crop epidemics.
140
How do you breed resistance into a crop population?
You take one susceptible elite crop and cross it with a resistant wild donor and after many back crosses, there is a resistant elite crop and from this we rely on sex and sexual reproduction.
141
Why are obligate asexual lineages so rare and short-lived?
Asexuals can't easily break up or recycle susceptible genotypes, so diversity is eroded, resistance is lost and populations crash or are outcompeted.
142
What are eco-evolutionary dynamics important in?
- ecosystem functioning
- nutrient cycling
-community composition
- divergence and speciation
- disease dynamics
- population dynamics.
143
What are eco-evolutionary dynamics?
Reciprocal interactions between the geology of populations, communities, and ecosystems, and the evolution of organismal traits on the same timescale.
144
What is an eco-evolutionary cane?
A species evolving in response to change in ecology.
145
What is eco-evolutionary change?
The evolution of a species generates ecological change for itself and other species.
146
When do eco-evolutionary feedbacks arise?
When eco-evo change and evo-eco change both occur.
147
What are the species that modify their own or other species' ecologies?
- keystone species
- niche construction and ecosystem engineers
- habitat modification
- changing nutrient cycline
- consumption of resources.
148
What do ecological variable generate?
Large selection coefficients on different phenotypes.
149
What is necessary for eco-evolutionary dynamics?
Genetic variation, trait hereditability and congruent timescales.
150
What is the evidence that genetic variation is necessary for eco-evolutionary dynamics?
The evidence is seen in algae and rotifer chemostat experiments where the results showed that predator-prey dynamics in multi-clone systems could evolve.
151
What is the evidence that congruent timescales are necessary for eco-evolutionary dynamics?
It is seen in Alewives fish which have anadromous forms and they go to lakes and rivers to breed and spawn and then the young spend their first summer in freshwater.
152
What is an example of non-eco-evolutionary feedback?
A example is in Anadromous Alewives, where there is a strong impact on zooplankton community structure in freshwater systems. However, the timescale of niche construction and recovery of zooplankton is out of step with the timescale required for evolution.
153
What are research approaches used for eco-evolutionary dynamics?
- natural populations in replicated streams, both with and without predation
- experimental introductions in natural systems
- capture-mark-recapture
- mesocosm experiments
- lab experiments.
154
What are the qestions you can ask to prove eco-evolutionary feedback?
Do __ affect their ecosystem in a manner that alters selection on them?
Do ___ evolve in response to their impact on the ecosystem?
Does ___ evolution, in turn, affect aspects of the ecosystem?
155
Why might we not see eco-evolutionary feedbacks?
- there's a lack of genetic variation
- there's incongruent timescales
- communities that are in their steady state need to perturb a system and see how it returns to equilibrium
- there might be weak per-capita interactions
- where species is rare
- where effect size is weak.
156
What are examples of anthropogenic perturbations?
- herbicide/pesticide use
- wildfire/fisheries extraction
- invasive species
- pollution
- climate change
- re-introductions
- translocations
- urbanisations.
157
What data is needed to characterise a population of a focal organism?
- individual attributes
- ecologically important phenotypic traits
- individual life history parameters
- population attributes
- demographic processes.
158
What data is needed to describe the evolutionary response of our focal species to the varied agents of selection?
- Follow individuals through a generation
- Hereditability
- follow focal population over time.
159
What data is required to look at community attributes?
- interacting species
- ecosystem attributes
- abiotic factors
- intraspecific variation can be a useful feature in study systems.
160
What happens when island syndrome is seen?
- giganticism
- wider ecological niches
- decreased aggression levels
- increased sedentary behaviour
- life history slows down.
161
What happens with predators and parasites on islands?
They tend to be underrepresented or unrepresented on islands and usually this is thought to be due to a lack of area/territory, or to do with a lack of prey.
162
What is the island rule?
A graded trend for insular vertebrates from gigantisism in small species to dwarfism in large species.
163
What has the island rule been observed in?
- mammals
- amphibians
- birds
- dinosaurs
- insects
- fish
- molluscs
- reptiles
- plants.
164
How is the island rule seen in birds?
- they have reduced dispersal and graviportal form which is mostly explained by raptor species richness and native mammal predator presence.
- the plumage brightness and dimorphism is decreased in signal intensity and complexity which could be due to lower levels of competition.
- They have slower life histories including lower fecundity, greater reproductive investment, longer development periods, and a trend for slower chick growth.
- there is reduced basal metabolic rates and increased cases of torpor as there is a restricted resource base, a variable environment, and an absence of predators.
165
How is the island rule seen in amphibians?
They always tend to grow larger, potentially due to the original small size of amphibians.
166
How is the island rule seen in mammals?
- Some mammals have 'low-ear' locomotion, which is where they have short and stout metapodials and develop slow, powerful locomotion.
- There is a reduction in body size but the 'low gear' locomotion isn't simply due to allometric downsizing.
167
What is the idea of behavioural naivety on islands?
In island macropods, there has been evidence for a loss of group size effects, more foraging, and being less vigilant. Island species are known to be more "tame" and looking out for predators less often. The island populations show a greater diversity of foraging behaviours than their mainland counterparts.
168
How does reduced interspecific competition lead to wider niches and higher densities on islands?
The reduced suite of parasites/predators has led to behavioural naivety, flightlessness, low-gear locomotion, and graviportal phenotypes. Reduced territoriality and aggression led to increased intraspecific competition.
169
How does the island rule lead to a population of large-bodied individual generalists?
Under conditions of low interspecific competition and low predation, there are spare niches that can be accessed with little risk. The removal of interspecific competition results in niche expansions. Larger-bodied individuals can access a broader range of resources, which produces a population of large-bodied individual generalists.
170
When is a stronger island rue relationship seen in birds?
It is seen in the absence of raptors.
171
How are island species represented in extinctions, and why?
Island species are over-represented in extinctions, with 95% of terrestrial bird and mammal extinctions being island species. This can be due to predators, humans, disease, and habitat loss or modification.
172
Why is the latitudinal diversity gradient seen in tropical rainforests?
It is seen due to higher speciation rates and lower extinction rates.
173
How much of life on earth is supported by rainforests?
75%.
174
How much of earth's surface is covered by tropical rainforests?
5%.
175
How much of all terrestrial biodiversity occurs in the tropics?
Over 85%.
176
How much land surface is covered by humid rainforests and how many plant and animal species does it support?
It covers around 6% of the land surface but supports over 50% of all plant and animal species.
177
What is an ancient evolutionary cradle?
A decrease in diversification since origin with early radiation.
178
What is the evolutionary museum model?
There is constant diversification rate and old lineages persist through time.
179
What is a recent evolutionary cradle?
An increase in diversification rate since origin with recent radiation.
180
What does the global phylogeny of palms suggest?
It suggests that the oldest lineages are ancient (over 100Myrs old) and that the diversification follows an evolutionary museum model.
181
What are the principle anthropogenic threats to tropical forests?
- logging
- fragmentation
- fire
- hunting
- conversion to agriculture
- climate change
- mining.
182
What are the consequences of the principle Anthropocene threats on tropical forests?
- biodiversity loss
- loss of ecosystem services
- carbon sequestration
- erosion control
- folding control
- climate regulation.
183
What is seen on small islands covered in forests?
- lacking predators of vertebrates
- densities of rodents, howler monkeys, iguanas, and leaf-cutter ants are 10-100 times greater than on the near mainland
- severely reduced densities of seedlings and saplings.
184
Can rainforests regenerate?
Yes.
185
What does fragmentation of forests create?
It can create "empty forests" and drive trophic cascades.
186
What does UN data and projection predict about secondary forests?
It suggests that secondary forests couple expand cushioning the effects of deforestation and this would be due to urban populations soon exceeding the rural population.
187
Are secondary forests good for species diversity?
No.
188
How does active forest restoration work?
It is where saplings are grown on mass in locations and then are planted out.
189
How much of rainforests are in protected areas and how much of protected areas cover eartt?
23% of tropical forests are in protected areas, which then cover 12% of the earth as a whole.
190
What is "leakage" from tropical forests?
It is where deforestation is displaces and people who farm or hunt in the area that has been protected will go and do the same thing somewhere else.
191
What are "paper parks"?
They are protected areas that aren't always effective which tend to be difficult to monitor and are often mainly inaccessible areas where forest threats are low, but there is no monitoring of the area, it just looks good to have protected areas.
192
What determines the ecological fate of protected areas and how can this be changed to be better?
Environmental changes immediately outside protected areas determine their ecological fate. Thee needs to be stemming of broad-scale loss and degradation of such habitats and reserves need to be connected.
193
Why is there so much forest exploitation in the tropics?
Most tropical countries are relatively low income and developing rapidly, meaning forests are seen as a resource to be exploited. Agricultural revenues increase temporarily then decline and standards of living, literacy and life expectancy follow the same pattern.
194
What are non-timber forest products and what are the challenges?
- they are products which are not related to timber that can be extracted directly from the forest.
- it depends on pollination by large-bodied solitary bees associated with natural forests.
- without management, intensively harvested populations will succumb to a process of senescence and demographic collapse.
195
What is biopropecting?
It is a potentially useful force of biologically-active compounds which have optional value. An example is a pharmaceutical company started lots of research in Costa Rican forests but nothing positive has been found.
196
How much of the worlds flora has been investigated?
5%.
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What are the pros and cons of ecotourism?
- it is a way to incentivise rainforests
- benefits tend to accrue to a minority
- it is vulnerable to political and financial instability.
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What does data from Borneo suggests is better- land sparing or land sharing?
Data suggests that forest sparing might be a better conservation strategy than forest sharing.
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What is an example of land sparing?
Riparian reserves are strips of forest along rivers, and they retain similar communities to the forest for many taxa and it can maintain ecosystem functions, while further from the river there is intensive farming.
