Forest Monitoring Flashcards
Which natural factors have affected the biodiversity in northern European forests?
Immigration patterns
Climatic fluctuations
Refuge populations
Disturbances such as: Wind, fire + fire refuge, insect attacts, humans
Which factors affect the biodiversity in forests?
Forest fire
– occurrence, interval and intensity
– tree species succession after fire
Occurrence and dynamics of gaps in the canopy
– mosaic of successional stages
– light gaps
– nutrient additions
• Continuity
– time to reach reproductive age
– dependency of structures that are developed after long time
– dependency of the microclimate in old growth forests
• Dead wood
– succession of necro fauna and flora on logs
– establishment of new trees
How does the forestry affect the bio diversity?
Clear-cuts, short rotation times, even-aged stands - Very little old forest, lack of stand continouty, changed stand climate
Ditching - Degrade wetlands, and forests on wet ground
Suppressed fires - Lack of fire-induced early succession and
burnt dead wood
Renewal by foreign tree species, provenances - Altered tree species composition, non-native species, non-site provenances
Reduction in amount and quality of dead wood - The largest single factor for decreased number of species (90% during 100 yr)
Decribe the factors that affect landscape fragmentation?
Altered landscape mosaic - Gives remeant biotopes and habitat fragmentation
Size of fragments - Larger are better, both directly and indirectly.
Fragment isolation - Can lead to inbreeding
Possibility to dispersal between fragments - Often ignored but very important. Part of the natura 2000 project but we generally know to little.
Genetic effects - Random demographic and enviromental factors may harm small populations.
Corridors - The form varies between species. The effect increases with width and quality.
Edge zones - Increased edge leads to higher predation, specialists from, different habitats co-occur.
Species with high risk for extinction
- Species at the top of the food web
- Species with local distribution
- Species with limited ability of dispersal
- Specialists
- Parasitic/symbiontic species
Describe DPSIR
A frame work by which policies are made:
Driving force - energy demand, life style, timber haverst, hunting license etc.
Pressure - Harvested area, ditches, alien tree species, S and N deposition.
State - Area of old forest, amount of decidiuos trees, dead wood, pH, nutrient balance, shot wild animals
Impact - Decrased bio div, uptake/relase of CO2, eutropfication, traffic accidents with wild animals.
Response - Forestry legislation, natyre conversation, refunds for attacts by large predators, fences along roads.
Environmental Quality Objective:
Sustainable Forests – Levande skogar
- The natural production capacity of forestland is preserved.
- The natural functions and processes of forest ecosystems are maintained.
- Natural regeneration is practiced wherever the land is suitablefor this method.
- The forests’ natural hydrology is protected.
- No remedial measures are taken against the effects of forest fires.
- Care-demanding forests with valuable natural and cultural assets are managed in such a way as to preserve and enhance these assets.
- Forests where there is great variation in the age of the trees and the composition of tree species are protected.
- Cultural monuments and environments are protected.
• Importance is attached to forests as sources of nature
experiences and recreation are taken into account.
- Endangered species and natural ecosystems are protected.
- There are viable populations of domestic plant and animal species living in natural conditions.
- Endangered species can spread to new habitats in their natural areas of distribution, thus ensuring viable populations.
- Alien species and genetically modified organisms that may be a threat to biological diversity are not introduced
Indicators of successs for sustainable forests
- Fraction damaged cultural remnants
- Amount of old growth forest
- Amount of hard dead wood
- Amount of hatching forest birds
- Amount of protected forest area – nature reserves
- Amount of protected forest area – biotope protection
- Amount of protected forest area – conservation agreements
- Area of old forests with a high fraction of deciduous trees.
What is the purpose enviromental quality criteria for the forest?
If possible they should tell if the measured state may cause effects on human health and/or human helath.
Or
Tell if measured value is high/low compared to the mean in Sweden
How is the deviation of the measured value assessed?
It is done by measuring it relative to dedcided reference value (an estimate of the pre-human conditions). This value is then given a value between 1-5 where 5 is the largest deviation from pre-human conditions.
Describe the levels, methods and important parameters that are used to qunatify biodiversity in forests?
In the landscape saterlite pictures, field work and GIS is ised to assess parameters like habitate distrubution, corridors, edge zones and fire zones.
In the habitate field work and saterlite are used to assess parameters like number of species, density relationships, indicators and key species.
On the species level population estimates/modelling and viability analyses are used. Factors that are assessed are frequency, distrubution, biomass, sex and age structure and fecundity.
On the genetic level morpholog varitaion, protein and DNA variation are studied to assess effective pop size, gene flow and heterozygocity.
Which factors does the Shannon diversity take into account when estimating diversity?
Number of species and the abundance of each specie.
What to alpha, beta and gamma say regarding biodiversity?
alpha - number of species in each sampling plot/unit
beta - Change in species composition between plots
gamma - Dibersity of the whole extent/forest/landscape
What are factors that can help in identifying a rare species?
What is the temporal trend? Any know threats? Is the species on national “Red lists”? What is the risk of extinction? Does the species provide an ecological function?
In what ways can diversity be measured?
Numerals: Spieces, genera families
Shannon diversity - Combination of quality and quantity
Genetic diversity - Is the diversity distrubed among or whitin the population?
Endemic - Rare in Sweden or everywhere?
