Climate change effects on ecosystems Charles Sheppard

Transcription

1 Climate change effects on ecosystems Charles Sheppard

2 Sea temperature rise

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7 (b) Warming when the thermostat is turned up one notch, people tend to expect one notch s worth additional heat, not a house in flames. N. Knowlton Threshold and non-linear responses 2004

8 (c) Warming and local effects: Bahrain 1985: Low diversity but high cover (~60% average)

9 Local impacts act synergistically with climate changes Slippery slope to slime (Pandolfi et al 2005) Scientist / Engineer dictionary: Reclaim = landfill on top of habitat Borrow pit = dredged reef / seagrass beds to get landfill material Soil improvement = flattening habitat for foundations Armouring = concrete shoreline replacing the natural one because we got it wrong Ecosystem received some impact = dead (oops!)

10 2. Effects (a) Ecosystem changes

11 Ocean acidification

12 Pteropods (Ocean potato chips) Shells becoming pitted

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14 Ocean Acidification 1880 Calculations of what CO2 Does in seawater 2000 Green=good 2050 Brown=bad

15 Summary schematic

16 Sea level rise and ecosystems

17 Many joke about sea level rise Not so funny for some

18 Bermuda Sea Level rise (e) Sea Level Rise level date In Bermuda: Between = 2 mm / yr Last 30 yrs = 2.7 mm / yr In 1990s = 5.3 mm / yr

19 Shoreline energy increases and increases erosion

20 Pseudo-sea level rise Sea level rise and coral mortality has caused a pseudo-sea level rise of an additional metre

21 Sheppard, C.R.C., Dixon, D. J,. Gourlay,M., Sheppard, A., Payet. R Coral mortality increases wave energy reaching shores behind reef flats: examples from the Seychelles. Estuarine Coastal & Shelf Science, 64:

22 Sea level rise and coral mortality and acidification (aragonite saturation state) combine to reduce the main wave barriers (to Maldives, Tuvalu, Kiribas etc)

23 Diseases on Coral Reefs Interactions with Climate Change

24 Many naturally occurring microorganisms are present but dormant become pathogenic with a rise in temperature or change in ph

25 Diseases of corals: increases of occurrences? White band Black band White blotch, etc. Identity of pathogens generally not determined yet. Some clearly a mix of bacteria and protozoa. In one case, SST rise triggers Vibrio, leading to bleaching.

26 Black band and white band coral diseases

27 Kinds of diseases White band disease

28 Black band disease

29 Black band disease and Red band disease

30 Diseases of sea urchins (Diadema) in Caribbean: Mass die-off. Spread from Panama (Pacific disease brought through canal by ship?). Disease fanned out across Caribbean, killing Diadema. Consequences: Diadema is a grazer. No grazing -> algal explosion, displacing corals

31 Identified causes: Toxin produced by Vibrio which inhibits photosynthesis Messing up of protein phosphorylation cell detachment Messing up of cell death pathways which deal with cell lysis Damage in the D1 protein of photosystem II and disruption of Calvin cycle. These occur in bleaching caused by high temp and PAR There must be more: darkness can lead to bleaching without damaging photosystem II

32 A global problem. Dust transport of diseases. Several hundred million tonnes per year from Sahara to Caribbean

33 And from China to western USA

34 The land Phenology

35 20. United Kingdom -- Toads, frogs, and newts spawning early. Spawning was 9 to 10 days earlier over a 17-year period. 21. United Kingdom -- Birds laying eggs early. From 1971 to 1995, 31 percent of 65 bird species studied in England showed significant trends towards earlier egg laying, moving up the date by an average of 8.8 days. 22. Southern England -- Early leafing of oak trees. The four earliest leafing dates occurred in the past decade, a response to increasing temperatures during January to March over the past 41 years. 27. Austria -- Alpine plants retreat up mountains. Over a 70 to 90 year period, alpine plants in the Austrian and Swiss Alps moved higher up on mountain slopes in response to an increase in average annual temperature. 29. Europe -- Butterfly ranges shift northward. 22 of 35 butterfly species studied have shifted their ranges northwards by 22 to 150 miles ( km), consistent with a 1.4?F (0.78?C) warming over the past century. 30. Germany -- Mollusc range shift. 20% of 40 mollusc species in a national park have changed their distribution in response to warming The Netherlands - Earlier flight peak of moths. Between 1975 and 1996 the flight peak of small moths shifted to a date 11.6 days earlier. Warmer temperatures promote the earlier appearance of insects and earlier peak flight times United Kingdom - British birds extend their ranges northward. A comparison of the breeding distributions of birds for two time periods, and , showed that the northern margins for many species had moved northwards by an average of about 12 miles (19 km). The range shift occurred during a period when central England s temperature warmed by about 0.9?F (0.5?C) over the last century, and the 10-year period was the warmest such period in the record.

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37 Bird migration Long distance (beyond Sahara) and short distance (not as far as Sahara). In all cases, birds now arrive earlier. Southward migration but not beyond the Sahara: delay autumn return. Southward migrations south of Sahara now go earlier, to avoid the Sahel s autumn dry period which starts ~ September.

38 Bird migration Oxfordshire migrants over past 30 years, average arrival is 8 days earlier, Their departure (these are long distance ones) is similarly earlier. These stay in Oxfordshire about the same length of time These long distance migrants also need to go further, lengthened by 300 miles (5%). Short distance trips about 125 miles more on average Subalpine Warbler 1,615 miles (1,895-2,081miles) - Southern Europe to sub-saharan Africa Orphean Warbler 1,679 miles (1,926-2,019 miles) - Southern Europe to sub-saharan Africa Barred Warbler 2982 miles (3480-3,573 miles) - Central Europe to sub-saharan Africa Common Whitethroat 3,417 miles (3,541-3,759 miles) All Europe to sub-saharan Africa

39 Bird migration Those with variable number of broods may extend to have another brood. UK has a very buffered maritime climate compared with continental climate: 8 days is not as great as e.g. American robins which have changed by 14 days In all cases, onset of breeding is advanced. Averages are useless. Patterns differ to suit each species needs. American robin

40 Bird migration What about migrants from the cold North? Waders and waterbirds are a good examples. Drops in numbers arriving in the UK attributed to warming in far north and continent, so they don t need to migrate. Such as Dunlin Dunlin Bewick s Swan

41 What about non-migrants? USA is bigger so more clear: 60% are moving north, average 35 miles some hundreds of miles. Some don t. And are declining in numbers Alternative is to higher elevation (cooler) Forecast ranges will be on average 500k m north by end of century, with reduced ranges Spruce grouse

42 And if they cannot change dates, disperse, move or climb higher? Pied Flycatchers in Med area: These didn t change their flying times Arrived too late to catch the earlier emergence of insects

43 Spawning errors (asynchrony) Fish in Mediterranean spawn on temperature cue Fish start migration patterns on temperature cue Their juvenile s food is plant plankton whose spring increase has a daylight length cue.

44 Changes to wine Rising stress from temperature and dessication: Rise of 13.3 points of 100 point vintage scale for every 1 degree rise in temp. Rise in alcohol of 2% over last 30 years

45 Disappearanc e of ecosystems

46 Tundra melting Arctic ice melt Also a thinning of 40%

47 People and mortality

48 Human Ecology. Rise of the human species

49 10. Human disease aggravation

50 Where Where did the fish have go? the fish gone?

51 Intensity has increased massively South China Seas trawlers stirring up mud

52 Which one should we NOT catch to ensure stock survival? 1 kg each: 1,000 eggs/year 10 kg each: 2,000,000 eggs/year

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