ECEC - 11 Flashcards
how can we predict future climate change impacts?
stimulation through manipulation experiments and gradient studies
how can we study past and current climate change impacts?
by monitoring populations or ecosystems over time
what have studies shown to be the impact of recent change on UK priority species?
massive loss of abundance of UK priority species since 1970
what are the main causes of the loss of abundance of UK priority species?
- Land-use change
- climate change and management
A study was conducted over the past 20-40 years on an area occupied by native plants, birds and butterflies to see the impacts of recent change, what was the effect seen on native plant species?
- 28% of native plant species have decreased although UK plant species to have good ability to survive change (median change +7%)
A study was conducted over the past 20-40 years on an area occupied by native plants, birds and butterflies to see the impacts of recent change, what was the effect seen on native breeding birds?
- 54% of native bird species have declined – a few species have thrived off the change but less than plants (median change - 2%)
A study was conducted over the past 20-40 years on an area occupied by native plants, birds and butterflies to see the impacts of recent change, what was the effect seen on native butterflies?
- 71% of native butterflies have declined – very large impact (median change -13%)
when combining the worst butterfly, bird and plant declines what did the data show about distributions?
- Local population extinctions recorded in all main ecosystems in Britain
- Extinctions distributed remarkably evenly across UK
- No evidence for “worse” areas –
though some contrasts expected
why was their a greater loss in butterflies compared to plants and birds?
because insect populations are more responsive to adverse environmental change than:
– longer lived organisms
– those with dormant propagules e.g. seeds
why has there be a problem in researching extinction risk regarding invertebrates?
– low sampling of invertebrates
– high tendency for higher trophic level vertebrate extinctions to be recorded (generally)
– have falsely suggested larger organisms more sensitive than invertebrates
why might the recent butterfly change be less serious in the future?
– Major clearances of primary vegetation occurred in an earlier age
– Climate warming has enhanced carrying capacity of British ecosystems to support
butterflies
– Targeted conservation measures (including regulation of collection and hunting) are
working
how might species range change with warming?
- species could maintain their abundance if they move north or to higher altitude
- highly mobile species are more likely to track climate change than sedentary species
- sometimes northern range limits are more sensitive than southern
when studying British butterfly ranges at a 0.6 degree increase what were the 2 changes observed?
1) No overall change in range margins
2) Species moved to higher elevations
what was the overall studied effect of temperature changes on the majority of the British taxonomic groups?
Shift in northern range margin - move north
+41m for northern species, +22m for southern species
what are 2 classic studies of stimulation experiments?
UK limestone grasslands ( most species rich plant communities) Buxton and wytham
what is the difference in fertility between the 2 limestone grasslands studied?
Buxton = ancient pasture with low fertility Wytham = more fertiles, early successional
what is the difference in fertility between the 2 limestone grasslands studied?
Buxton = ancient pasture with low fertility Wytham = more fertile, early successional
what is the definition of resistance?
ability of the plant community to maintain composition and
biomass
what is the definition of resilience?
rate of recovery
which of the 2 limestone grassland studied is more resistant to global change and why?
buxton - Infertile system – slow growing, long lived perennials with persistent shoot and root systems
- Opportunities for establishment of
new individuals rare & low influx of
propagules from outside
what is a PCA?
- principle component analysis
- Summarises plant community composition
- Plots close together have similar composition
what did PCAs show about the plant community composition of wytham compared to buxton?
- Buxton – little change
- Wytham – large divergence of
communities
how do early successional and mature communities respond differently to climate change?
• Early successional, fertile communities of fast growing, short-lived species
will respond rapidly to climate change
• More mature, less fertile communities will respond more slowly
what effect is land use change having on plant communities?
- Land-use change is replacing unproductive systems with more fertile
systems
– making plant communities more responsive to climate change
what did studies on European heathlands show about succession and global change?
- the more “in succession” the ecosystem, the more responsive to global change - Ancient stable ecosystems more resistant to global change
what is a tensioned landscape and an example?
- Ecosystem under pressure from climate change – No current change despite pressure (i.e. an ecosystem under tension) – Disturbance my trigger sudden shift - e.g. heathlands and upland grasslands
describe the change in spring leaf phenology unfolding and start of season?
- Unfolding advanced 0.42 d y-1
- SOS advanced 0.67 d yr-1
Less advance more recently (2000-2011)
– Cooling trend in late winter delaying early
spring species
– Late spring species still responsive to warming
springs
