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Climate Change and Biodiversity: Impacts Lecture I Alpine Summer School 2008 “Interaction and Coevolution of Climate and Biosphere” Camille Parmesan Integrative Biology, University of Texas at Austin 1 Outlines of 2 Lectures • Impacts I (Tuesday) – Attribution via scientific inference – Observed species’ range shifts – Conservation implications • Impacts II – – – – (Wednesday) Observed phenological shifts Consequences of phenological changes Observed evolution and limits to adaptation Implications of climate change for human health 2 Intergovernmental Panel on Climate Change Attribution question Causal link between biological changes and anthropogenic climate change? Impacts question Are changes negative, neutral or beneficial? Proportion of biodiversity affected at given point? Vulnerability question Which species most at risk? Which regions most sensitive? Effectiveness of reserve system? 3 Linkages Among Environmental Issues Ozone Depletion Climate Change Habitat Loss Sulfate Aerosols Desertification Biodiversity Impacts Water Nitrogen inputs Air pollution Biological Problems with Individual Studies • Multiple anthropogenic forces (confounded) •Climate change •Land use change •Habitat loss (urbanization, agriculture) •Increases in N, P, C, uv • Positive publishing bias • High yearly variance - difficult to find trends • Variable quality (sampling, missing data, spatial and temporal scales) • Most good datasets are short term (20 yr) & local scale (generality?) 5 Hypothetical Species’ Range Map Extrapolation of species range shift from single study sites is error prone Parmesan 1999, 2001a,b, 2004, 2005 6 ATTRIBUTION Causal Links to Climate Change are from scientific inference, not direct experimentation • Correlational Patterns – Long-term patterns --- Observed biotic changes match climate change trends in direction and magnitude – “natural experiments” --- empirical demonstrations of biotic responses to extreme weather events and climate years • But, causal mechanism inferred from experiments – Field Manipulations of temperature and precipitation – Laboratory Experiments on thermal and desiccation tolerances Edith’s checkerspot butterfly range has shifted northward 92 km and upward 124 m during the 20th c. Most extinctions in south and at low elevations Historical records 1860-1980 Census 1993-1996 green = present purple = extinct 8 Parmesan Nature, 1996 Extinction Clines across range of E. editha 50 40 40 30 30 20 20 10 0 n= 15 10 74 36 10 N Latitudinal Bands 16 0 n= 42 20 23 37 29 3 45 0 50 2 40 0 60 1 80 0 60 12 0 0 70 60 0 70 0 % Popu la tion s Ex tinc t 80 Elevational Band (m) From: Parmesan, C (1996) Nature 382:765-766 9 Elevation Extinct Present < 2400 m ✝ ▲ ≥ 2400 m ✝ ▲ ✝▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲▲ ▲▲ ▲ ✝✝ ▲ ▲✝ ✝ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲▲ ✝ ▲ ▲ ✝ ✝ ✝▲ ✝✝✝ ▲ ✝ ▲✝ ▲▲ ▲ ✝ ✝ ✝ ▲ ▲ ▲✝ ▲✝ ✝ ✝ ✝ ▲ ✝✝ 500 ▲ ✝ ✝✝ km ✝ ▲ ▲ ▲ ✝ ▲ ▲ ▲ ▲▲ ✝▲✝ ✝▲ ✝ ✝ 100 Results of 19931996 census by elevation ▲ ▲▲ ▲ ▲▲ ▲▲✝✝ ▲ ▲ ▲✝ ✝✝ ▲ ▲▲ ▲ ▲ ✝✝▲ ▲ ▲ ▲ ▲ ▲✝ ✝ ✝✝✝ ▲✝ ✝ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ✝✝✝✝ ▲ ▲ ▲ ▲ ✝ ▲ ✝ 10 Lighter Snowpack below 8,000 ft has increased Probability of False Spring Events Photo removed 11 Johnson et al. 2000 Climatic Connections • 0.7º C warming over Western USA → climatic shift of 105 km North & 105 m up (Karl et al. 1996) E. editha: mean location shifted 92 km North & 124 m up (Parmesan 1996) • Both snowpack & E. editha extinction trends shift at 2400 m: % Δ snow/50 yrs – Below 2400 m – Above 2400 m % extinctions 14 % less snowpack ; melt 7 d earlier 8 % more snowpack ; no Δ melt 46 % 14 % (T. Johnson, 1998) ATTRIBUTION Example: Edith’s Checkerspot butterfly • Correlational Patterns – Long-term patterns --- range shift matches temperature isotherm shift and matches patterns of snowpack dynamics (Parmesan 1996, Karl et al. 1996, Johnson 1998) – “natural experiments” --- below 2400 m, population extinctions occur in drought years • > 20 populations across California over 40 years of censusing (Singer & Ehrlich 1979, Singer & Thomas 1996) • Field Manipulations • Laboratory Experiments 13 Confounding Factors • • • • • • Genetic diversity Age of population Population size Population isolation Topography Human influences – Habitat degradation – Secondary effects of urbanization • Resource use – - influences of host plant genus 14 Confounding Factors • NO - Genetic diversity not different in populations that went extinct compared to those that didn’t • NO - Age of population (record) • NO - Population size (habitat size) • NO - Population isolation • NOT STRONGLY - Topography • NO - Human influences • Habitat degradation • Secondary effects of urbanization • YES - Resource use – host plant genus DOES affect likelihood of extinction, but not responsible for range shift Climate and E. editha : Direct field measures • Observed natural population extinctions caused by single extreme climatic events (> 20 populations over 40 years) • Temporal & spatial variation of climate strongly correlated with population dynamics across species range – Intensive study of 2 metapopulations (20 & 40 yrs), spotty study on > 15 other populations (much of sp. range) • Yearly temp./precip. variability ➔ host density and phenology (senescence) ➔ Offspring starvation • North and South slopes (macro & micro landscape) ˛ temp./water ➔ local dynamics host/larvae • Habitat patch types ˛ patch temp/water ➔ flight seasonality ➔ independent dynamics ➔ colonization 16 Climate and E. editha : Experiments Manipulations of larvae into different thermal environments in the field • 4 independent studies/multiple populations • Relative phenology of larvae and host plant: • strongly affected by thermal regime • crucial determinant of female fitness • 2-3 three day shortening of host lifespan (earlier senescence) can increase %larval starvation from “normal” 98% to 100% 17 ATTRIBUTION by INFERENCE Example: Euphydras editha butterfly • Correlational Patterns - YES – Long-term patterns (100 years) --- range shift matches temperature isotherm shift and matches patterns of snowpack dynamics (Parmesan 1996, Karl et al. 1996, Johnson 1998) – “natural experiments” (40 years) --- below 2400 m, population extinctions occur in drought years and following false springs (light snowpack). Above 2400m, booms occur with heavy snowpack (Singer & Ehrlich 1979, Singer & Thomas 1996, McLaughlin et al. 2002) • Field Manipulations - YES – manipulating thermal environment (slope aspect, habitat type) affects larval growth rates, pupal times, synchrony with host plant, and colonization success (Singer 1972, Weiss et al. 1988, 1993,, Boughton 1999) • Laboratory Experiments - YES – temperature increases larval growth rates (Weiss et al 1988, Hellmann 2000) 18 An Unbiased Estimate of Species’ Responses to Climate Change • Minimize confounding factors •Studies in relatively undisturbed environments • > 20 years data (avg. 44 years, max 140 years) • Publishing bias: only include multi-species studies • Estimate proportion of species responding • Unique biological fingerprint? • Climate change only plausible driver 19 Root et al. 2003 Global Phenological Trends n = 109 ?? 5.2 d/dec advance (mostly northern temperate zone) Count 50 45 Parmesan & Yohe 2003 40 n = 172 35 2.3 d/dec advance 30 25 20 15 10 5 0 -35 -30 -25 -20 -15 -10 days / decade: earlier -5 0 5 20 later Whole Range Study of 57 Species Across Europe Photo removed 21 Parmesan et al. Nature 1999 More Statistical Problems • Sampling methods have changed at various times - e.g. Moth bait changing in mid-1950s led to dramatic increase in recorded species diversity • Sampling intensity has increased through time - increases in density of sampling points could lead to false estimate of range expansion 22 Checquered skipper Photo removed 23 65 % of 52 species had colonized northward at northern range boundary (30-200 km, 30-100 years, 0.6° C) Purple emperor (Apatura iris) Pu r p l e Em p ero r 20 ° E Fi nl a nd (A pa t ur a i r is ) 60° Photo removed Esto n ia N 58° Sw e de n De n m ar k Blue arrows: 1900 to 1999 Parmesan et al. Nature 1999; Unpublished Ryrholm, Kaila & Kullberg Green arrows: 2000 to 2003 >100 km expansion 24 22 % of 40 species contracted at southern range boundaries * 1 species range reduction Parmesan et al. Nature 1999 Heode s t it yr us 20 ° E 60° Sooty copper (Heodes tityrus) Invasion of Estonia (green) 1998 - 1st record 1999 - breeding populations 2004 - spread to Baltic Sea Fi nl a nd Es t o ni a N Sw e de n 56° Fra n c e 42° Spa i n 40° Ca t al o nia 4° E Extinction in Catalonia (light grey) 1930s - common nr Barcelona 1990s - southern-most population 25 100 km N in Pyrenees Summary of Distributional Changes in 57 Species of European Butterflies (Parmesan et al. Nature '99) Going N Going S Northern Edges : Binomial test Stable 65 % 2% P << .001 34 % 22 % 5% P < .04 72 % 63 % 6% P << .001 29 % (52 species) Southern Edges : (40 species) N & S Edges same species : (35 species) 26 Summary of Distributional Changes in 57 Species of European Butterflies (Parmesan et al. Nature '99) Going N Stable Northern Edges : Going S Binomial test 66 % 34 % 0% P << .001 22 % 72 % 5% P < .04 66 % 29 % 3% P << .001 (52 species) Southern Edges : (40 species) N & S Edges same species : (35 species) 27 Changes in Northern / Upper Range Limits among Temperate Species 100 80 60 north / upslope mean 6.1 km-m /decade 40 20 0 south / downslope -20 -40 -60 -80 -100 Observations bird butterfly herb taxa ns different Parmesan & Yohe, Nature 28 2003 Observed changes studies published up to July 2002 Nminimum (#species or functional groups) Changed in direction predicted (n) Changed in opposite to prediction (n) Stable (n) trees, shrubs, herbs birds, frogs butterflies 242 43 % 6% 52 % at poleward range edges (high elevation limits) trees, herbs, mammals, birds butterflies 150 63 % 13 % 15 % at equatorial range edges (low elevation limits) birds, butterflies 186 13 % 9% 77 % cold-adapted shrubs, herbs, reptiles, amphibeans, fish, marine zooplankton & invertebrates 141 27 % 1% 71 % 115 85 % 11 % 3% Type of change taxa studied Phenological Distributional changes (expansions & contractions along range edges) community changes (local abundance changes) (Parmesan & Yohe 2003) warm-adapted No prediction (n) 10 % 1% Out of 1570 species, about half were stable 29 Estimated: More than Half of Wild Species have Responded to 20th c. Climate Change (>1500 species / species groups) Changed as predicted (n) Changed opposite to prediction (n) P 87 % 13 % < .1 x10-12 Distributional changes: At poleward/upper range boundaries At equatorial/lower range boundaries 81 % 75 % 19 % 25 % Community (abundance) changes: Cold-adapted species Warm-adapted species 74 % 91 % 26 % 9% 81 % 19 % Type of Analysis Phenological N = 484 / (678) N = 460 / (920) Meta-analysis Range-boundaries (n=99) Phenologies (n=172) 6.1 km-m/decade < .1 x10-12 .013 northward/upward shift 2.3 d/decade advancement < 0.05 Diverse species of: trees, herbs, shrubs, reptiles, amphibians, fish, marine zooplankton, marine invertebrates, mammals, birds butterflies 30 (Parmesan & Yohe, Nature 2003) Thought Exercise revisited p = Probability of competing explanations (confounding factors) π = Probability that observed change is really due to climate (mechanistic link) n’/n = Proportion of species going in opposite direction to climate change predictions Binomial probability model with each factor varying from 0 to 1 Here, p=0 1 Confidence Regions 0. 75 Very high High ! 0. 5 Medium Low Minimum Probability (!) !estimated confidence 0. 25 fromliterature review 0 0 0. 2 0. 4 (n'/n) Proportion 0. 6 0. 8 31 Very Long Biological Time Series Provide a Second Type of ‘Fingerprint’ Global Average Temperature 32 Diagnostic Biological Fingerprint “Sign--switching” • Temporal Advancement of timing or northward expansion in warm decades ('30s/40s & '80s/'90s); delay of timing or southward contraction in cool decades ('50s/'60s) • Spatial Exhibited different behaviors at extremes of range boundary during particular climate phase, e.g. expansion at northern range boundary simultaneous with contraction at southern range boundary during warming period • Community Abundance changes have gone in opposite directions for cold-adapted vs. warm-adapted species. E.g. lowland birds increasing and montane birds decreasing at mid-elevation site. 33 Shifts in Nationality: Novel Species Sooty copper (Heodes tityrus) Photo removed Heode s t it yr us 20 ° E 60° Fi nl a nd Es t o ni a N Sw e de n 56° Fra n c e 42° Spa i n 40° Ca t al o nia Invasion of Estonia 100 km north 1998 - 1st record 1999 - breeding populations 2002 - increase #populations & northward expansion 2005 - reached Baltic Sea 4° E Contraction northward 50 km in Spain 1930s: common in Montseny mts, Catalonia 1980s - present: Extinct in Catalonia, southern-most populations in the Pyrenees mts Parmesan et al. 1999 34 Marine systems show declines of northern species and increases of southern species Shifts in fish community Holbrook et al. 1997 35 Diagnostic Biological Fingerprint • “Sign-Switching” uniquely predicted by climate change scenarios found for 279 species sign-switching pattern Community Abundance changes have gone in opposite directions for cold-adapted vs. warm-adapted species. Usually local, but many species in each category. Diverse taxa, n=2821 Temporal Advancement of timing or northward expansion in warm decades ('30s/40s & '80s/'90s); delay of timing or southward contraction in cool decades ('50s/'60s) 30-132 yrs per species. Diverse taxa, n=441 Spatial Exhibited different responses at extremes of range boundary during particular climate phase. Data from substantial parts of both northern and southern range boundaries for each species. All species are northern hemisphere butterflies, n=8 % of species showing diagnostic pattern 80% 100% 100% 36 Diagnostic Biological Fingerprint • “Sign-Switching” found for 294 species – 100% follow decadal trends in temperatures (range shifts and phenologies) – 100% show geographic contractions coupled with expansions at opposite edges of species range – 80% of abundance shifts in communities (local population dynamics noisy) (Parmesan & Yohe 2003) 37 Studies of Observed Impacts on Natural Biological Systems are Increasing • 2001: IPCC TAR - 8 USA studies; ~20 global • 2004 : Parmesan and Galbraith, Pew Report • 40 USA studies (same criteria as synthesis analysis in IPCC 2001) • 21 studies “strong evidence”, >237 species (stricter criteria than IPCC 2001) • 2003 : Parmesan & Yohe, Nature • 32 global studies (multispecies) • > 1530 species/groups 38 Number of publications documenting a response of a species, community or system to recent climate change (up to Jan. 2006) #publications = 866 #species = several thousand Parmesan AREES 2006 39 State of Science Impacts high Established but incomplete Level of Well - established Climate Change Attribution agreement: Consensus Speculative Competing explanations low low high Amount of evidence (observations, theory, model outputs, etc.) 40 2004 Parmesan & Yohe, Nature 2003; Parmesan & Galbraith, Pew Brief review of some specific impacts 41 Arctic Sea Ice down by 40% this year (Area = ~half of lower USA lost) ~2-3° C Magenta line = mean 1979-2000 = 6.74 mil Sq miles NOAA, National Snow & Ice Data Center Ringed Seal • Declines in abundance, Hudson Bay Polar bear • Need 2 kg fat / day • Land animals & berries too lean • Increase in ice-free season • Increased summer starvation period • Declines in abundance & weight, Hudson Bay • Declines weight & #cubs, Alaska & Norway Stirling et al 1999; Derocher et al 2004; Derocher 2005; Ferguson et al 2005 Polar bear • Declines in abundance & weight, Hudson Bay • Declines weight & #cubs, Alaska & Norway Ringed Seal • Declines in abundance, Hudson Bay NOAA, National Snow & Ice Data Center Stirling et al 1999; Derocher et al 2004; Derocher 2005; Ferguson et al 2005 44 Changes in Sea Ice Driving Species Range Shifts Ice-dependent species declining by 70 - 95% • Ice-adapted Adelie & Emperor – moving poleward • Warm-adapted Chinstrap & Gentoo – Arrived 20-50 years ago Smith et al. Bioscience 1999; Fraser et al. Polar Biol. 1992; Emslie et al. Ant. Science 1998 Ice-dependent species increasing or smaller declines (<20%) 45 Pikas are Sensitive to Heat •live > 7,500 feet •Must forage > 9 x / day Smith 1974 46 Mountaintop Species : mac • Sensitive to Heat • Losing habitat as they are forced to contract upward American pika • Live only > 7,500 feet • Eat constantly • Adults killed by > 31° C (~ 90° F) • Hide on hot days - starvation Smith 1974 Low Elevation Populations Don’t Forage Mid day 9,000 ft August 9,000 ft •Adults killed by heat stress ( > 31° C in sun) •Foraging time limited by temperature May 12,500 ft August Smith 1974 48 Upward shift of the pika • 7 / 25 populations have gone extinct since 1930s • Extinct populations were at lowest elevations Beever et al. 2003 Ice Age Still present extinct 49 Tropical highland frogs are going extinct • Cloud forest species require mist • Population crashes followed years with high #dry days, > 5 mist free days in a row Pounds et al. Nature501999, 2006 Extinctions of harlequin frog species (Atelopus) in central america cloud forest Pounds et al 2006 Figure 1 | Altitudinal patterns in the Atelopus extinctions. Bars indicate the number of species known per altitudinal zone (total n •96), and the grey-shaded portions represent the estimated percentage of species lost from each. This percentage differs among zones 51 #species seen for last time (black line) related to air temp (blue line) 78% of species seen for last time were preceded by an extremely warm year Pounds et al Nature 2006 52 a) Elevation and min & max temp along mt gradient in Costa Rica. Blk dashed is thermal optimum, red is thermal range, for Batrachochytrium (chytrid) fungus b) #species of harlequin frog at each elev (max upper boundary) Pounds et al Nature 2006 Change in min & max temps at Monteverde 53 Andean Glacial Retreat: 3 species of frogs + fungus migrated 400 m upward over 70 years (0.3 ° C /decade) 1931 5000 m 2005 5400 m Pleurodema marmorata Bufo spinulosus Telmatobius marmoratus **Chytrid fungus Seimon et al. GCB 2007 Shrubs expanding into tundra in Alaska, Canada Sturm et al.2001, unpubl Shift in Alaskan tundra carbon balance: From sink 1980s to source 1990s/2000 Losing 40 gC/m2/year First signs of positive feedbacks Oechel et al., Nature 2000 55 2004 Parmesan & Galbraith The toucan and other lowland tropical birds have moved uphill, threatening high elevation birds. Hydrology and glaciers Sea-Ice Animals Plants Studies covering Studies using large areas remote sensing 56 Tropical species have moved into USA from Central America, into Europe from Africa Florida: 4 new species of dragonflies (1960-2000) Paulson 2001 Rufous hummingbird • Migrant 1900-1990 •Resident by 1996 Texas: 5 new species of butterfly • Colonized 400 km inland by 1998 Hill et al. 1998, Howell 2002 ???? Mexican jay now resident 57 Community Replacement Marine copepod plankton - community indicators in NE Atlantic – up to 1000 km northward shifts over 40 year Beaugrand et al. Science 2002 58 Whole Ecosystems can collapse with single extreme temperature event Coral Reefs and extreme Sea Surface Temperatures (SST) 59 60 In 1998, coral bleaching affected every part of the world’s oceans •95% of coral bleached in Maldives, Western Australia, Okinawa and Palau •16 % of reefs killed Aug 18 Feb 61 Hoegh-guldberg 1999 62 Hoegh-guldberg 1999 63 Ocean acidifica tion Hoegh-guldberg et al Science 2007 64 Why is Climate Change a Conservation Problem? • Individual species have different responses and lag times - led to disruption of communities and novel (non-analog) communities during past major climate changes • Climate change adds yet another threat - wild life may be able to cope with 1 threat, but not 3 simultaneously • Modern ecosystems have lowered resiliency than they did during past major (natural) climate changes 65 Why is Resiliency Lower? • Invasive species generally thrive in stressed conditions • Coastal industry and urbanization limit the potential for rising sea levels to simply move intertidal habitats (e.g., saltmarshes) inland. • Natural ecosystems increasingly are confined to smaller and more isolated fragments with reduced population sizes, leading to: • Diminished genetic variation - could limit local adaptation. • Difficulty in simple shifts of species’ distributions. • Decreased successful dispersal • Lowered probability of successful colonization (farther to travel & coming from smaller source populations within impoverished communities). 66 So Species’ Shift around with Climate Change Why is this a Problem? 52° N 48° N 44° N 40° N Patterns of Edith’s Checkerspot Population Extinctions in natural areas (good habitat) 36° N % extinctions > 70 % 32° N 35 - 55 % < 20 % 67 Loss of Habitat Add Climate Change Endangered Sub-species of Euphydryas editha Endangered Sub-species of Euphydryas editha E. editha taylori E. editha taylori E. editha bayensis E. editha bayensis E. editha quino E. editha quino 68 • • • No evidence for macroevolution (emergence of novel adaptive traits within species) Microevolution may facilitate species’ persistence – Selection for high dispersal phenotypes improves changes of range shifts keeping pace with climate change – Species with variation of climate-adapted genotypes contain genetic flexibility to cope in situ High end of climate change projections problematic: – Some habitats completely lost (tundra, alpine, coral reefs?) – outside of evolutionary history of many species – Unlikely for existing genetic variation to be sufficient 69 70 Evolution in populations of D. subobscura •Large #s of inversions • Frequencies of inv change with altitude and latitudinal clines •Freq of inv change seasonally •Both maintained dynamically by selection because movement high Balanya et al 2006: Change in direction of the chromosome index over time parallel those in the temperature index at 22 of 26 sites (upper rt and lower lft quadrants). Black european; red N American; blue 71 S American. 1st pc explains 45% Micro-evolutionary Responses • Changes in gene frequencies within populations are occurring • Expect first evidence of evolutionary adaptation to climate change in species with short generation times • Many insects have generation time of 1-2 weeks 72 Long-term increases in frequencies of warmadapted genotypes •D. melanogaster (4 deg. latitude shift in alcohol dehydrogenase genes) • D. subobscura (Europe, N & S America) •D. robusta (USA) • Pitcher plant mosquito (Wyeomyia smithii) (shift in photoperiod cue for diapause, USA) (Rodriguez-trelles & Rodriguez 1998; Balanya et al. 2003, Gilcrest; Levitan et al. 2003, Bradshaw & Holzapfel 2001; Hoffmann et al. 2003) Selection for high dispersal genotypes at expanding range boundaries: • Increase in frequencies of long-winged morphs along northern colonizing wave in 2 sp. of bush cricket (Thomas et al 2001) 73 BUT - No Evidence for Macro-evolution (i.e. across whole species) • No response to artificial selection to tolerate more extreme conditions than found in wild • D. birchii (desiccation tolerance, Australia) (Hoffmann et al. 2003) • No evidence for new “super hot” mutations • Paleological studies show similar stability of morphology over short climate fluctuations (1000s of years) • Fossil evidence indicates major climate regime shifts associated with high extinction rates • Evolution of novel forms takes 2 - 3 million years 74 75