Degradation Hotspots Lecture

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Degradation HotspotsDegradation Hotspots

NREM 612

1Degradation of Human-Dominated Ecosystems

OutlineOutlineOutlineOutlineI. Definition & Selection of Biodiversity

HotspotsII. Plants, Mammals, Marine SystemsIII. Degradation Hotspot Examples:• Aral Sea & Iraqi Marshes (Desiccation)q ( )

• Madagascar & Haiti (Deforestation)

• Coasts of SE Asia & Australia (Acid SulfateCoasts of SE Asia & Australia (Acid Sulfate Soils)

• Sunda Islands, Indonesia (Reef

, (Overexploitation)

Biodiversity Hotspots Biodiversity Hotspots (Myers 00)

• 25 Terrestrial Biodiversity Hotspots: Areas w/ high conc. of endemics & high loss of habitat

• Boundaries: biogeographic units (i.e. islands, or ecol. islands), expert judgment

• Criteria• Criteria#1) Area must contain at least 0.5% (or 1,500) of world’s

~300,000 plant species as endemics#2) After meeting #1, hotspot should have lost ≥70% of its

1o veg.#3) T t i l l#3) Terrestrial realm• 4 vertebrate groups (mammals, birds, reptiles,

amphibians) serve as back-up support & to determine p ) p pp &congruence; don’t have to meet 0.5% of global totals

25 Terrestrial Biodiversity Hotspots: Areas w/ high conc. of endemics (>1,500) & high loss of habitat (>70% of original primary vegetation)

16 hotspots in tropics (forests), 5 in Mediterranean zones, 9 mainly/completely islands

4Myers et al. 2000. Nature 403:853-858.

Biodiversity Hotspots (Myers 2000)Biodiversity Hotspots (Myers 2000)

• Contain remaining habitat of 133,149 (44%) plant g , ( ) pspecies & 9,645 (35%) of vertebrates

• Occupy 2.1 million km2 (1.4% of land surface)

15/25 contain >2 500 endemic plants 10 contain• 15/25 contain >2,500 endemic plants, 10 contain >10,000

• 11/25 have lost 90% of habitat, 3 lost 95%

Hottest HotspotsHottest Hotspots (Myers 2000)Hottest Hotspots Hottest Hotspots (Myers 2000)

• Criteria: 1) endemic plants, 2) endemic vertebrates, 3) endemic plants/area (spp/100 km2), 4) endemic vertebrates/area (spp/100 km2), ) % f5) remaining 1o vegetation as % of original extent

Σ # of times appearing in top 10 for each criteriaΣ # of times appearing in top 10 for each criteria

Tie for first place: Madagascar, Philippines, Sundaland (5Tie for first place: Madagascar, Philippines, Sundaland (5 each)

25 Terrestrial Biodiversity Hotspots: Areas w/ high conc. of endemics (>1,500) & high loss of habitat (>70% of original primary vegetation)

* *****

7Myers et al. 2000. Nature 403:853-858.

*8 hottest hotspots based on endemic plants, vertebrates, p/area, v/area, remaining 1o veg

Issues with Myers’ Hotspots (Brookes et al. 2002)

For oceanic islands, habitat loss underestimates extinction b.c. invasive spp have driven extinction beyond those caused by habitat loss

In large hotspots habitat loss overestimates extinctionIn large hotspots habitat loss overestimates extinction

Scale dependence-Hotspots of different sizes & larger areas hold more endemics; nonlinearareas hold more endemics; nonlinear

Residuals = relative densities

8Original area

Factor out area-Factor out arearelative density of endemic plants

Determine 11Determine 11 hottest hotspots:Madag., Philippines, Sundaland, Braz Atl for Carrib Indofor, Carrib, Indo-Burma, Western Ghats, Tanz-Kenya, Medit Basin, Trop Andes, MesoAmer,

Brookes et al. 2002. Cons. Biol. 16:909-

923.923.

Other Criticisms of Myers’s HotspotOther Criticisms of Myers s Hotspot Approach• Emphasis on plant species, doesn’t consider higher taxonomic groups (mammals, reptiles, fish, etc.)

• Overlooks crucial biotas such as wetlands, especially tidal marshes (have low richness & endemism)

• Hotspots don’t account for large carnivores (i.e. polar bears, grizzly bears, wolves, lions)g y )

• Save 1.4% & pave everything else

(Kareiva & Marvier Amer Sci 2003)Amer Sci 2003)

Marine BMarine Biodiversityiodiversity Hotspots Hotspots (R b t t l 02)(Roberts et al. 02)

Mapped ranges of 1,700 reef fish, 804 corals, 662 snails, 69 lobsters

Used cell size of 50 000 km2 (224 km per side)Used cell size of 50,000 km (224 km per side)Mapped richness & endemism w/i & among taxaMapped threats to coral reefs based on dvpmt, pp p ,

overexploitation, marine & land-based pollution (Bryant et al. 1998)

M d i t ti f d i & th t f h t tMapped intersection of endemism & threats = reef hotspots

Fish80

Corals

Snails

Lobsters

200 Lobsters

Richness ( ll

erts Richness (all

Threats (blue=low, red=high)

Corals Top 10% of cells in terms of #s of endemics (&

Snails

endemics (& range<10 cells)

Lobsters

Concordance patterns of endemism for each taxa

(red included all 4, orange =3, y=2, b=1)

18 Marine biodiversity hotspots

* *****

5 most threatened: Philippines (14), Gulf of Guinea (3) Sunda Is (17) S Mascarene Is (15)

14 of 18 are adjacent to terrestrial biodiversity

Guinea (3), Sunda Is. (17), S. Mascarene Is. (15), Eastern S. Africa (10)

14 of 18 are adjacent to terrestrial biodiversity hotspots as identified by Myers et al. 2000

16Roberts et al. 2002. Science 295:1280-1284.

17Roberts et al. 2002. Science 295:1280-1284.

Mammalian Mammalian Dist., Dist., Hotspots, & Hotspots, & Conservation Conservation (Ceballos & Ehrlich 06)

• Global examination of all nonmarine mammals (4,818) to determine patterns in richness, endemism, & endangermentendangerment

• Compare dist. in 17,800 equal-area cells (100 km per side)

• Hotspots defined as top 2.5%, 5% of cells in each category

• Test for congruence among categories & across cells

RichnessEndemism

Threatenedea e ed

Richness: Concentrated in tropicsEndemism: Found on all continents, concentrated in islands, island-like habitatsTh t d C t t d i / hi h i t h ti it

(Ceballos & Ehrlich PNAS 2006)

Threatened: Concentrated in areas w/ high-impact human activity

Richness Endemism

Threatened

Richness: 2 main regions (Central & S. America, equatorial Africa)Richness: 2 main regions (Central & S. America, equatorial Africa)Endemism: Mex, C. & S. Amer, Mada, Sri Lan, Idones, N Guinea, Philipp, TaiwanThreatened: S. Amer., eq. Africa, Mada, Western Ghats, Indonesia

N h l (1% ll ) Σ ll t 2 5% 5% f l d

20(Ceballos & Ehrlich PNAS 2006)

No much overlap (1% common cells), Σall at 2.5% = 5% of land area

2.5% HotspotsArea in 10,000 km2

(% total land surface)Number of species (% total mammal spp)

Richness 443 (2.4%) 1,265 sp (26%)

Endemism 128 (1.0%) 1,525 sp (32%)

Threatened 409 (2.3%) 2,257 sp (47%)

T t l i ll h t t 859 k 2 (4 7%) 2 833 (59%)Total in all hotspots 859 km2 (4.7%) 2,833 sp (59%)

(Ceballos & Ehrlich PNAS 2006)

Global Mapping of Human Impact on Global Mapping of Human Impact on Marine EcosystemsMarine Ecosystems (H l t l 08)Marine Ecosystems Marine Ecosystems (Halpern et al. 08)

Synthesized 17 global datasets of anthropogenic drivers of y g p gecological change (benthic structures, comm. shipping, ocean-based pollution, species invasion, climate change [acidification, UV, sea temp], fishing [artisinal, low-bycatch, high-bycatch, habitat , p], g [ , y , g y ,modifying], direct human, pollution [NP inor, NP org, nut input])

F 20 i t t ( fFor 20 marine ecosystem types (coral reefs, seagrass, mangroves, soft shallow, soft shelf, rocky reefs, hard shelf, soft slope, hard slope, soft deep, hard deep, pelagic waters, seamounts, deep waters)deep waters)

Global map of cumulative human impact across the oceans (2008)

23Halpern et al. 2008. Science 319:948-952.

Highly-Impacted: (B) Eastern Caribbean, (C) North Sea, (D) Japanese waters

Least-Impacted: (E) Northern AustraliaLeast Impacted: (E) Northern Australia

Final Final Thoughts Thoughts on Myer’s on Myer’s Hotspot ApproachHotspot Approach

• MacArthur Moore World Bank Cons Int have granted• MacArthur, Moore, World Bank, Cons. Int. have granted $750 million in response—largest sum for any single cons. strategy

• Endemism: No restoration biology to regenerate extinct species

• Adopted for marine systems• Adopted for marine systems• Cited 2,224 times as of 4/13/09 (Web of Science)• E.O. Wilson: “the most important contribution toE.O. Wilson: the most important contribution to

conservation biology of the last century.”

12 12 SoilSoil Degradation HotspotsDegradation Hotspots

Science 11 June 2004: 304(5677):1614–1615.

Aral Sea:Aral Sea:

Shrinking since 1960 due to diversion ofdue to diversion of water from 2 rivers (Syr Darya Amu(Syr Darya, Amu Darya) to irrigate nearby crop land

(K. Mussner, 2005, www.wikipedia.com)

311989 (Jul.-Sep. Landsat mosaic, 250 m resolution, NASA)

19731973

2000(Landsat images from NASA)

•Salt concentration ↑ from 10‰ to >23‰, contributing to devastation of a once-thriving fishery

•Local climate shifted, w/ hotter, drier summers & colder, longer winters

•As water retreated, salty sediment remains on the exposed sea bed. Dust storms disperse ~75,000 tons yr-1 of exposed sediment, dispersing salt particles, pesticidesediment, dispersing salt particles, pesticide residues

•Air pollution caused widespread respiratory il tailments

•Crop yields diminished

(Perera, J., 1993; Micklin, P.P., 1992; Rich, V., 1991; Perera, J., 1988; United Nations Environment Programme, 1992)

Wetlands of IraqWetlands of Iraq

(http://visibleearth.nasa.gov/view_rec.php?vev1id=9687)

Reflooding of h hthe marshes

since 2003(UNEP, 2005)

39(UNEP, 2006)

MadagascarMadagascarMadagascarMadagascarOne of the most biodiverse areas on the planet-8,000 endemic species of flowering plants (Green & Sussmanendemic species of flowering plants (Green & Sussman1990)

•Numerous habitats degraded since arrival of humansNumerous habitats degraded since arrival of humans 1,500-2,000 ya (Humbert 1927, Dewar 1984)

•Extinctions of large mammals, birds-severe (Humbertg , (1927, Dewar 1984)

•If deforestation rates continue unchecked, only forests on steepest slopes will survive (G&S 1990)

41(www.wildmadagascar.org)

OnsiteOnsite

OffsiteOffsiteOffsiteOffsite

High sediment loads in the ManamboloHigh sediment loads in the Manambolo River (www.wildmadagascar.org)

44Betsiboka River and estuary, image from Space Shuttle (NASA)

45FAO National Soil Degradation Map: 2004. Severity of Human-Induced Soil Degradation in Madagascar

HaitiHaiti

Originally ~ 93% forestedOriginally 93% forested,1923 forest cover > 60%,1950 forest cover = 25%1950 forest cover 25%,1987 forest cover = 10% 2000 forest cover = 3%2000 forest cover 3%

2005 forest cover = 1.4%

(Library of Congress Federal Research Division 2006; USA Today 2005)

47(NASA)

48(www.engr.colostate.edu/ ~pierre/ce_old/Projects/)

Paul Jeffrey/ACT International

www.oreworld.org/images/ environmental-aerial.jpg

SE Asia & Australian Coasts:SE Asia & Australian Coasts:A id S lf t S ilAcid Sulfate Soils

When salt marsh soils drained, O2 penetrates il idi it (F S ) & lfid (S ) t f isoil, oxidizes pyrite (FeS2) & sulfide (S2) to ferric

iron (Fe(OH)3) & sulfuric acid (H2SO4) in reactions shown below:

FeS2 + 15/4O2 + 7/2H2 ⇒ Fe(OH)3 + 2H2SO4

S2 + 3O2 + 2H2O ⇒ 2H2SO4

•Acid leachate plus Al Fe & heavy metalsAcid leachate, plus Al, Fe & heavy metals which it releases from soils, cause significant environmental, economic problems

50•Restoration extremely difficult

Global Distribution of Acid Sulfate SoilsGlobal Distribution of Acid Sulfate Soils

Country Area (ha*1,000) SourceIndonesia 4,109 Soekardi 1990Australia 3,000 Galloway 1997Vietnam 2 140 Bui Quang TranVietnam 2,140 Bui Quang Tran

1990Venezuela 2,000 van Breman 1980Thailand 1,500 Krishnamra 1990Guyanas 1,246 Brinkman and

Pons 1968Brazil 1,111 FAO 1974

53UNEP Environmental Assessment Program for Asia and the Pacific, Bangkok, 1998

Sunda IslandsSunda Islands•The Sunda Islands hotspot encompasseshotspot encompasses some 12,639 km2

•Part of the “Coral Triangle ” the mostTriangle,” the most diverse coastal area on earth Hi h i i•High marine species

richness & endemism •Threats include: (1) ( )land-based pollution, (2) destructive fishing practices, (3) live reef

p , ( )fish trade

Indonesian Reef (Carl Gustav, World Bank)

56Reefs of Iryan Jaya, Indonesia(Photo Rod Salm WWF)

(http://courses.washington.edu/larescue/projects/devin/index3.htm)

57(Bryant et al. 1998)

(Bryant et al. 1998)

59(Bryant et al. 1998)

Plume of fine silts and clays discharging into the sea in

60(http://www.dfid-kar-water.net/w5outputs/soil_erosion_slides.htm)

Indonesia.

Other threats

(http://courses.washington.edu/larescue/projects/devin/index3.htm)

61(Photo: Reefbase/ T. Heeger )

• The Bajo fishing community of Sampela on the island of Kaledupa, Indonesia

• Until around 40 years ago, the Bajo or “sea nomads” would spend their lives at sea in communities distributed across SE Asiasea in communities distributed across SE Asia

• Recent gov’t pressure has resulted in building of more permanent villages

• Bajo dependent upon marine resources for virtually all their food, fuel, building t i l

63(www.envf.port.ac.uk/ geo/courses/indonesia/)

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Degradation Hotspots Lecture

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