Lecture 4c: species level climate change impacts: plasticityasticity Flashcards
Key questions in relation to distribution
How is distribution and changes to it monitored?
How is distribution determined by climate change?
What methods are used to assess the impact of climate change?
What are the impacts of climate change on distribution?
Species responses to climate change
See again Huntley et al. (2010) figure 1:
Sequence of events (predicted)
Change in abundance and behaviour
Geographic redistribution
Adaptive micro and then macro-evolution or extinction
Monitoring distribution - a question of scale
Brown et al. (1996) blue tit distribution is vast – surveying all their inhabited locations is near impossible. Centre of a species range is thought to be the most optimal in conditions
^ medium size studies are usually used
remember to consider potential vs actualised niches
blue tit dist. is comparable to great tit:
a similar distribution but slightly different adaptations as range is extended into Asia suggesting more varied adaptation
other bird species have a v. limited niche compared to blue tit despite similar evolutionary history
Drivers of Avian Occurrence and Abundance
climate the most influential down to topography in species dist and abun
from Franklin 1995, Thuiller et al. 2004, Howard et al. 2014 :
*Climate
*Geology
*Land Use
*Topography
^ all contribute to define species distribution and abundance
· Hierarchical scheme of environmental controls
· Distinguish finer scale variations in habitat quality
. Effects of climate studies at coarser scale
*What controls where species occur?
*One of the biggest drivers is climate, but not just temperature
*Reliance upon vegetation and other taxa as prey species
*Topography can affect species occurrence; think of things like butterflies where they will inhabit certain aspects of a slope; south facing for example
Citizen science schemes
for macroscale understanding of species distribution
e.g. iNaturalist
Butterfly Conservation
PECMBS (pan european bird monitoring)
Distribution data
GBIF - global biodiversity information facility
MOVEBANK - has animal tracking data
Key Q and A
How might climate change impact distribution? Latitude and altitude range shifts, rising sea levels habitat loss
Will all species be impacted equally? no
How can we study these impacts? - plants are easiest to study and influence other species dist.
Climate driven changes in distribution
Range shifts:
3 main habitat scenarios:
1.suitable now, not in the future
2.suitable now, and in the future
3.not suitable now, but in the future
when an area becomes unsuitable, populations in this area die out and they may shift to colonise new available range
hence the term ‘range shift’
see diagrams in notes
Distribution range paper 1: Parmesan 1999
Abundance/distribution records for >600 species over time periods of 17 – 137 years:
*Woody plants, herbaceous plants, shrubs
*Lichens
*Birds, mammals, reptiles and amphibians
*Insects
*Fish
*Marine invertebrates
*Marine zooplankton
Distributional responses paper 2:
Rapid Range Shifts of Species
Associated with High Levels
of Climate Warming Chen et al
^ Meta-analysis across four continents, 1367 species, and 8-94 years:
*Insects
*Spiders
*Fish
*Birds
*Mammals
*Algae
*Herptiles
*Plants
-16.9km poleward shift per decade
-11m upslope shift per decade
Temperature driven range shifts:
Poleward range shifts
“63% have ranges that have shifted to the north by 35-240 km during this century”
Parmesan et al (1999)
“all bird species (n=129) included in this analysis showed an average northward range shift in their mean latitude of 3.58km”
Zuckerberg et al (2009)
Temperature driven range shifts:
Upslope range shifts
Mean elevations for birds shifted
significantly upslope by 40 ± 98 m (n = 65
species; 43 species shifted upslope vs. 15
downslope vs. 7 with no change)
Freeman et al 2018
“lower elevational limits for 16 butterfly species in central Spain have risen on average by 212m (± SE 60) in 30 years”
Wilson et al 2005
(bird and butterfly studies again as these taxa are the most studied)
Tropical range shifts
tropical range shifts are controlled by rainfall and weather as well as topography, mountain ranges and wind force – making shifts much harder to observe/interpret
^ not much clear directional shift
see VanDerWal et al 2012 map in notes
Effect on species abundance
Variable
species gaining range tend to survive better but still experience decline because:
Many species are not keeping pace with climate change Devictor et al 2012 as a result there is still decline as often species cannot keep up with the speed of range shift resulting from climate change
Factors limiting climate tracking
^e.g. altitudinal range shifts lead to loss of peak dwelling species ‘escalator to extinction’
^ latitudinal losses are also occuring in polar species
Dispersal
Limited natal dispersal/long generation times – particularly an issue for small/sessile organisms (plants and herptiles)
Geographic barriers – mountain ranges/oceans – species at the poles/top of mountains have nowhere to go – “escalator to extinction” (Urban, 2018)
Species interactions
Presence of competitors, predators, or pathogens
Lack of prey, hosts, or mutualists
Land-use change - agricultural land can be hard to inhabit/traverse etc.
Climate determines coarse-scale suitability, but suitable habitat required for colonisation and persistence
Projecting impacts: species distribution models
See WorldClim and Birdlife international
Environmental layers, Species distribution
& Physiological requirements (Mechanistic approach)
can be fed into an SDM algorithm
The resulting model is checked by statistical
validation
Then the model is projected in time and/or
space
Creating potential current distribution map estimate
and
potential LGM distribution
^ which is validated by comparison with records of fossils, pollen, phylogeography, etc.
see projections according to predicted emissions in notes
Future predictions
continuing poleward rangeshifts
but tropical range shifts harder to predict
Barbet-Massin et al 2012
declining range size and issues with lack of habitat connections to newly available range
^ Huntley et al 2008
migratory species: polewards shifts in its ranges occurring in both directions resulting in diverging ranges long distance migrants are experiencing diverging ranges means they will have to migrate further
^Howard et al 2018
Range shift impacts in migratory species
Survival (Rushing et al., 2017)
*Migration period of highest mortality in the annual cycle
*Food scarce
*Predators en-route
Reproduction
*Arrive in worse condition
* Arrive later – exacerbate phenological mismatch
Ecosystem services lost (Bauer & Hoye, 2014)
* Nutrient and energy transport
*Pest control – birds consume insects
*Seed dispersal – birds disperse seeds and improve their germination
Summary
Distributions are monitored at a variety of scales
*Fine-scale monitoring built up into larger picture – aids understanding of niche theory and relationships between climate and fitness
*Climate typically controls distribution as coarse scale – so typically studied at scale of ~50km2
*Variety of citizen science monitoring schemes and associated datasets available
Range shifts in response to climate change now well-documented
*Typically poleward and upslope - >15km and 10m per decade, respectively
*Responses in tropics less uniform – distribution controlled by water-availability – less gradation
Can lead to declining population sizes
*Poor dispersal abilities, lost or novel species interactions, and habitat availability
*Arctic and alpine species under threat – nowhere to go!
^ As are small and sessile organisms
Species distribution models (SDMs) an ever growing technique
*Though see weaknesses (e.g. Howard et al., 2023 Nature)
Most responses already observed are forecast to continue
Migratory species particularly threatened
*Range shifts leads to larger migrations, which will require more stopovers and take longer
*Potential increase in mortality and reduction in productivity
