The Terrestrial Experience: Species Diversity and Ecosystem Functioning Diana H. Wall Dept Biology & Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO Image by D. Bumbarger: The head of the nematode Acrobeles complexus magnified 2500X
Terrestrial experience: species diversity and ecosystem processes Biodiversity and EF The world and tests of the 1990 s Global networks Ecosystem Services Challenges
Terrestrial experience: species diversity and ecosystem functioning Biodiversity and EF Timing is everything The world of the 1990 s The tests of the 1990s Ecosystem Services Challenges
Reid & Miller (1989) the Scientific Basis for Conserving Biodiversity, World Resources Institute; Vitousek (1994) Ecology 75:1861-1876; National Oceanic and Atmospheric Administration (NOAA), USA. (Slide courtesy of Berrien Moore, USA)
Timing: The Red List of Threatened Species IUCN - The World Conservation Union 1.75 M species described of 13-14 M species estimated One of 4 mammal species and 1 of 8 bird species risk extinction
The main threats to biodiversity
Timing in science 1970 s - Robert May - no evidence of species number related to ecosystem stability
Systematics Ecosystem Science Nutrient cycling hydrology Morphology, Molecular Methods 1-2 genera, order Ecosystem processes Biodiversity of 1, 2 groups Natural history Food Webs
Biodiversity Taxonomy Ecosystem Science Initiatives - ATBI Management - Organism to hot spots of biodiversity Species extinctions Initiatives - NSF LTERs, IPCC Management - Large scale, carbon loss, carbon gain, landscape and regional
Biodiversity The variability among living organisms within genes, species, between species, and of ecosystems. Convention on Biodiversity, 1992
Terrestrial experience: species diversity and ecosystem functioning Biodiversity and The world of the 1990 s The tests of the 1990s Ecosystem Services Challenges
The time was right Convention on Biological Diversity (1992) SCOPE Committee on Biodiversity and Ecosystem Functioning Tests of Hypotheses: Tilman and Downing, 1994, Naeem et al., 1994; Tilman et al., Nature, 1996; Hector et al., 1999
BIODIVERSITY ECOSYSTEM FUNCTIONING Diversity within species Diversity of species Diversity of functional groups Diversity of landscapes Transpiration Primary production Decomposition Nutrient mineralization
environment low diversity community response high diversity community response TIME OR SPACE McNaughton 1993
Biodiversity and Ecosystem Functioning Ecosystem function rivet null redundant 5 10 15 20 25 Number of species Vitousek and Hooper 1993
Hypotheses Healthy ecosystems depend on more species Biodiversity Productivity Diversity (the more species) keeps an ecosystem stable Biodiversity Ecosystem Stability BIODIVERSITY ECOSYSTEM STABILITY
Biodiversity and Ecosystem Function Manipulation, Perturbation Field, Lab Ecosystem function 1.0 0.8 0.6 0.4 0.2 0.0 Diversity Functional Response
Manipulative Biodiversity Experiment Cedar Creek Grassland 342 plots 13 X 13m 0-32 species Tilman and Downing, 1994
More species results in greater plant biomass Total plant cover (%) 65 60 55 50 45 40 35 30 25 0 5 10 15 20 25 Species richness treatment Redrawn from Tilman et al. Nature 379:718-720 1996
More species will buffer ecosystem from drought Deviation from pre-drought biomass 0.35 0.00-0.35-0.7 resistance 0 5 10 15 Plant species richness in 1989 Redrawn from Tilman and Downing Nature 367:363-365 1994
Cedar Creek Grassland Biodiversity Experiments Are more species better? Higher rates of production, nitrogen use efficiency and resilience to drought were associated with the presence of the C4 tallgrass big blue stem. WHO may matter as much as HOW MANY.
Our results demonstrate that the loss of species threatens ecosystem functioning and sustainability. Tilman et al., Nature, 1996
Hypotheses Biodiversity Productivity Empirical evidence BIODIVERSITY ECOSYSTEM FUNCTIONING Biodiversity Ecosystem Stability
Ecotron experiment: Naeem et al. Nature 368:734-737 1994
Ecotron experiment Predators Herbivores Plants Decomposers High Medium Biodiversity Low Redrawn from Naeem et al. Nature 368:734-737 1994
Ecotron experiment Plant Cover % change in vegetation cover 16 14 12 10 8 6 4 2 0 30 60 90 120 150 180 time (days) High Medium Low Redrawn from Naeem et al. Nature 368:734-737 1994
BIODEPTH experiment Pan-European study of the importance of biodiversity in grassland ecosystems 0-32 plan species
BIODEPTH Experiment Productivity declines with fewer species Hector et al. 1999 Science 286: 1123-1127
Models: Will loss of functional groups affect ecosystem functioning? Shoots Roots Root feeding nematodes Collembola Mites I Predaceous mites Inorganic N Labile substrates Mycorrhizae Saprophytic fungi Mites II Fungivorus nematodes Predaceous nematodes Nematode feeding mites Resistant substrates Bacteria Flagellates Omnivorous nematodes Bacteriophageous nematodes Amoebae (Hunt and Wall, Global Change Biology 2002)
Summary Biological production and ecosystem stability sometimes occurs with species richness but can be idiocycratic. Dominant species, species traits and not just species number i.e. species composition might be as or more important than species richness. Species interactions can change the shape of the diversity-functioning relationship.
Tests ongoing, but different approaches Functional groups Species removals Species traits Complementarity
Terrestrial experience: species diversity and ecosystem functioning Biodiversity and EF Global Biodiversity Initiatives Ecosystem Services Challenges
Global Biodiversity Initiatives
Africa BIOTA West Yemen Development of interdisciplinary strategies for the sustainable management and conservation of biodiversity in Africa Climatology Botany Zoology Mycology Soil science Animal production Socio-economy Modelling Remote sensing Namibi a BIOTA South South Africa BIOTA East Concept: BIOTA S06, 2002 Botanical Institute University of Hamburg, Germany
The Terrestrial experience Tests of Hypotheses: Tilman and Downing, 1994, Naeem et al., 1994; Tilman et al., Nature, 1996; Hector et al., 1999 International Biodiversity Observation Year - Diversitas (2001-2002) Daily, Nature s Services (1997), Costanza Millennium Ecosystem Assessment (2005)
Biodiversity provides benefits to humans
Organisms, links to services, their vulnerability to threats SCOPE Committee on Soil and Sediment Biodiversity and Ecosystem Functioning D. Wall, Chair Co-Chairs: L. Brussaard, R. Bardgett M. Palmer, A. Covich P. Snelgrove
Service Waste recycling Soil & sediment formation Linking the organisms to a service Soil & Sediment biodiversity Saprophytic and litter feeding invertebrates (detritivores), fungi, bacteria Bioturbators, termites, fungi, eubacteria Carbon sequestration Mites, nematodes, rotifers, polychaetes, annelids, clams, shrimp Biotechnology Microbes, Nematodes Wild food Mushrooms, clams, crayfish, earthworms van der Putten et al., 2004
Compare Services in a temperate unmanaged vs managed grassland Food production Water quality Water volume ranked for key species, contribution of abiotic vs biotic factors van der Putten et al., in Wall (ed), 2004
Target - 2050 Assessment
Ecosystem Services: the benefits people obtain from ecosystems Provisioning Goods produced or provided by ecosystems food fresh water fuel wood genetic resources Regulating Benefits obtained from regulation of ecosystem processes climate regulation disease regulation flood regulation Cultural Non-material benefits from ecosystems spiritual recreational aesthetic inspirational educational Supporting Services necessary for production of other ecosystem services Soil formation Nutrient cycling Primary production
Consequences of change for Human Well-being Supporting Nutrient Cycling Soil Formation Primary Production Provisioning Food Water Fiber... Regulating Climate regulation Disease regulation Water purification... Cultural Spiritual Religious Aesthetic... Ecosystem Services Security Personal safety Resource access Secure from disasters Material Livelihoods Food Shelter Health Strength Feeling well Clean air and water Social Relations Social cohesion Mutual respect Ability to help others Freedom of Choice and Action Opportunity to be able to achieve what an individual values doing and being Life on Earth: Biodiversity Constituents of Well-Being
Status of Regulating and Cultural Services Regulating Services Air quality regulation Climate regulation global Climate regulation regional and local Status Water regulation +/ Erosion regulation Water purification and waste treatment Disease regulation +/ Pest regulation Pollination Natural hazard regulation Cultural Services Spiritual and religious values Aesthetic values Recreation and ecotourism +/
NOTE NO DOLLAR AMOUNT
Grassland Biodiversity, Productivity and Stability Are Related 24-year study of Inner Mongolian Grasslands Community-level stability arises from complementarity Bai et al. 2004. Ecosystem stability and compensatory effects in the Inner Mongolian Grassland. Nature 431:181-184b 184b
TODAY services Kremen (2005) Ecology Letters
Today Dobson et al. (2006) Habitat loss, trophic collapse, and the decline of ecosystem services. Ecology 87:1915-1924.
Global Scientific Initiatives Loreau et al. (2006) Diversity without representation. Nature 442:245-246.
The terrestrial experience was a Convergence of: Manipulative experiments for empirical data Based on collaborations across disciplines Global networks of biodiversity Assessment of biodiversity & ecosystem services
Ecosystem Services Comparative global experiments are needed for quantifying services and processes Knowledge of the species and their distribution Include dependencies of different habitats
Reid & Miller (1989) the Scientific Basis for Conserving Biodiversity, World Resources Institute; Vitousek (1994) Ecology 75:1861-1876; National Oceanic and Atmospheric Administration (NOAA), USA. (Slide courtesy of Berrien Moore, USA)
Atmosphere-Biosphere System respiration Carbon Cycle photosynthesis food production forest production
Challenges Manipulated lab, field and microcosm International, coordinated tests of hypotheses Species, community and ecosystem levels Gaps: scale: above-belowground: non linear responses under climate changes: quantification of services
Climate Change Effects on Ecosystems Meta-analysis of 1,700 species showed Pole-ward (upward) shift of 6.1 km per decade. Parmesan and Yho (2003). Nature 421:37-42