INDEKS KELESTARIAN LINGKUNGAN = Environmental Sustainability Index Diabstraksikan oleh: soemarno, psdl ppsub, desember 2012 Bahan Kajian pada MK. PSDAL.

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1 INDEKS KELESTARIAN LINGKUNGAN = Environmental Sustainability Index Diabstraksikan oleh: soemarno, psdl ppsub, desember 2012 Bahan Kajian pada MK. PSDAL BIODIVERSITAS

2 BIODIVERSITY = KEANEKA RAGAMAN HAYATI Diunduh dari: http://woentari-monica.blogspot.com/2012/05/pengertian-keanekaragaman-hayati-dari.html……………… 4/12/2012 1.Keragaman hayati (biodiversity atau biological diversity) merupakan istilah yang digunakan untuk menggambarkan kekayaan berbagai bentuk kehidupan di bumi ini mulai dari organisme bersel tunggal sampai organisme tingkat tinggi. Keragaman hayati mencakup keragaman habitat, keragaman spesies (jenis) dan keragaman genetik (variasi sifat dalam spesies) 2.Keanekaragaman Hayati adalah tingkat variasi bentuk kehidupan dalam suatu ekosistem tertentu, bioma, atau seluruh planet. Keanekaragaman Hayati adalah ukuran dari kesehatan ekosistem. Keanekaragaman Hayati adalah sebagian fungsi dari iklim. Pada habitat darat, daerah tropis biasanya kaya sedangkan daerah-daerah kutub dukungan spesies yang lebih sedikit. Perubahan lingkungan yang cepat biasanya menyebabkan kepunahan massa. Salah satu perkiraan adalah bahwa kurang dari 1% dari spesies yang telah ada di Bumi yang masih ada. 3.Keanekaragaman Hayati adalah keseluruhan variasi berupa bentuk, penampilan, jumlah, dan sifat yang dapat ditemukan pada makhluk hidup.Keanekaragaman hayati merupakan lahan penelitian dan pengembangan ilmu yang sangat berguna untuk kehidupan manusia.

3 KEANEKARAGAMAN HAYATI Diunduh dari: http://staff.blog.ui.ac.id/andreas.pramudianto/2009/02/27/keanekaragaman-hayati-dalam-hukum-lingkungan- internasional/ ……………… 4/12/2012 Keanekaragaman hayati menekankan pada semua jenis spesies tumbuhan, hewan dan mikroorganisme juga dengan ekosistimnya dimana mereka merupakan bagian yang tak terpisahkan, termasuk jumlah dan frekuensi ekosistem, spesies dan gen yang saling berkaitan. Ada tiga macam keanekaragaman hayati, yaitu : a. Keanekaragaman spesies (Species Diversity) b. Keanekaragaman ekosistem (Ecosystem Diversity) c. Keanekaragaman genetika (Genetic Diversity)

4 Keanekaragaman spesies / jenis (Species Diversity) Keanekaragaman spesies terbentuk oleh adanya kesesuaian kandungan genetika yang mengatur sifat dari kebakaan dengan lingkungan terhadap anggota jenis yang sama yang dalam hal ini memiliki kerangka dasar, komponen genetika khususnya kromosom yang sama. Diunduh dari: http://staff.blog.ui.ac.id/andreas.pramudianto/2009/02/27/keanekaragaman-hayati-dalam-hukum-lingkungan- internasional/ ……………… 4/12/2012 Species Richness Index: Simpson’s Index Simpson gave the probability of any two individuals drawn at random from an infinitely large community belonging to different species. The Simpson index is therefore expressed as 1-D or 1/D. Simpson’s index is heavily weighed towards the most abundant species in the sample while being less sensitive to species richness. It has been shown that once the number of species exceeds 10 the underlying species abundance distribution is important in determining whether the index has a high or low value. The D value which is standing for the dominance index is used in pollution monitoring studies. As D increases, diversity decreases. (diunduh dari: http://webcache.googleusercontent.com/search?q=cache:CN372gBQkCwJ:ocw.unu.edu/)

5 Species Diversity Indices: Shannon-Wiener Index Shannon and Wiener independently derived the function which has become known as Shannon index of diversity. This indeed assumes that individuals are randomly sampled from an independently large population. The index also assumes that all the species are represented in the sample. Log2 is often used for calculating this diversity index but any log base may be used. It is of course essential to be consistent in the choice of log base when comparing diversity between samples or estimating evenness. The value of Shannon diversity is usually found to fall between 1.5 and 3.5 and only rarely it surpasses 4.5. It has been reported that under log normal distribution, 105 specieswillbe needed to produce a value of Shannon diversity more than 5. Expected Shannon diversity is also used (Exp H’) as an alternative to H’. Exp H’ is equivalent to the number of equally common species required to produce the value of H’ given by the sample. The observed diversity (H’) is always compared with maximum Shannon diversity (Hmax) which could possibly occur in a situation where all species were equally Abundant. Species Diversity Indices Shannon-Wiener Index Shannon and Wiener independently derived the function which has become known as Shannon index of diversity. This indeed assumes that individuals are randomly sampled from an independently large population. The index also assumes that all the species are represented in the sample. Log 2 is often used for calculating this diversity index but any log base may be used. It is of course essential to be consistent in the choice of log base when comparing diversity between samples or estimating evenness. The value of Shannon diversity is usually found to fall between 1.5 and 3.5 and only rarely it surpasses 4.5. It has been reported that under log normal distribution, 10 5 specieswillbe needed to produce a value of Shannon diversity more than 5. Expected Shannon diversity is also used (Exp H’) as an alternative to H’. Exp H’ is equivalent to the number of equally common species required to produce the value of H’ given by the sample. The observed diversity (H’) is always compared with maximum Shannon diversity (H max ) which could possibly occur in a situation where all species were equally abundan Diunduh dari: http://staff.blog.ui.ac.id/andreas.pramudianto/2009/02/27/keanekaragaman-hayati-dalam-hukum-lingkungan- internasional/ ……………… 4/12/2012

6 Keanekaragaman ekosistem (Ecosystem Diversity) Merupakan suatu kesatuan lingkungan yang melibatkan unsur-unsur biotik, faktor fisik (iklim, tanah dan air) dan faktor kimia (keasaman) yang saling berinteraksi. Beberapa tipe (kelompok) keanekaragaman ekosistem antara lain : 1.Ekosistem bahari: Terdiri dari ekosistem laut dan ekosistem pantai 2.Ekosistem darat”: Terdiri dari vegetasi dataran rendah, vegetasi pegunungan dan vegetasi munson. Diunduh dari: http://staff.blog.ui.ac.id/andreas.pramudianto/2009/02/27/keanekaragaman-hayati-dalam-hukum-lingkungan- internasional/ ……………… 4/12/2012 An ecosystem is a community plus the physical environment that it occupies at a given time. An ecosystem can exist at any scale, for example, from the size of a small tide pool up to the size of the entire biosphere. However, lakes, marshes, and forest stands represent more typical examples of the areas that are compared in discussions of ecosystem diversity. The diversity of an ecosystem is dependent on the physical characteristics of the environment, the diversity of species present, and the interactions that the species have with each other and with the environment. Therefore, the functional complexity of an ecosystem can be expected to increase with the number and taxonomic diversity of the species present, and the vertical and horizontal complexity of the physical environment. (Sumber: http://cnx.org/content/m12156/latest/#roth)

7 KEANEKARAGAMAN GENETIKA (GENETIC DIVERSITY) Setiap kerangka dasar komponen genetika tersusun ribuan faktor kebakaan keturunan. Satu faktor pengatur kebakaan disebut gen, suatu lingkungan yang memuat tumbuhan yang liar/sudah didomestikasi. Diunduh dari: http://staff.blog.ui.ac.id/andreas.pramudianto/2009/02/27/keanekaragaman-hayati-dalam-hukum-lingkungan- internasional/ ……………… 4/12/2012 Keanekaragaman genetik (genetic diversity) adalah suatu tingkatan biodiversitas yang merujuk pada jumlah total variasi genetik dalam keseluruhan spesies yang mendiami sebagian atau seluruh permukaan bumi yang dapat didiami. Ia berbeda dari variabilitas genetik, yang menjelaskan kecenderungan kemampuan suatu karakter/sifat untuk bervariasi yang dikendalikan secara genetik. Pengukuran keanekaragaman genetik Keanekaragaman genetika suatu populasi dapat diperkirakan dengan menggunakan beberapa pengukuran sederhana. 1.Keanekaragaman gen, adalah proporsi lokus polimorfik diseluruh genom. 2.Heterozigositas, adalah jumlah rata-rata individu dengan lokus polimorfik. 3.Alel per lokus, juga digunakan untuk mendemonstrasikan variabilitas. (sumber: http://id.wikipedia.org/wiki/Keanekaragaman_genetik)

8 Biodiversity Variety of living things, number of kinds Ecological diversity different habitats, niches, species interactions Species diversity different kinds of organisms, relationships among species Genetic diversity different genes & combinations of genes within populations Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎

9 Manfaat Biodiversitas Fungsi ekosistem Jasa-jasa Ekosistem Membersihkan air, Cleaning air, Habitat & breeding areas for wildlife, … Manfaat estetika dan budaya Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎

10 Vital economic natural resources – Renewable Forests (plants, wildlife) Soils Fresh water (lakes, rivers) Wildlife and fisheries Rangeland – Nonrenewable Minerals Fossil Fuels Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Sumberdaya Alam

11 Management of natural resources – Assure availability of resources for the future – Three “philosophies” Maximum sustained yield Ecosystem-based management Adaptive management Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎

12 New food sources –Grains, fruits, vegetables, meat, fish Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Manfaat Biodiversitas

13 Pengobatan: Plants Jellyfish & sea anemones Nudibranchs Marine slugs Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Manfaat Biodiversitas

14 Berapa besar biodiversitas 1.7—2.0 million species Estimates to 100 million Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Biodiversitas

15 Dimana biodiversitas? – Everywhere Every continent and habitat has unique life forms – Concentrated in the tropics Panama: > 500 species of breeding birds Arctic: 50-100 species – Dense concentrations Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Biodiversitas

16 Kepunahan & Reduksi Populasi – Perburuan & Panen berlebihan Tiger Dodo Whales Sharks – Kehilangan Habitat Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Ancaman Biodiversitas

17 Extinction and population reductions – Pollution – Climate change – Invasive species Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Ancaman Biodiversitas

18 How can we protect biodiversity – Stop overharvesting Sustainable yield Hunting & fishing laws (every state ?) – in developing nations ? – Protect habitat Refuges, parks, preserves – Endangered Species Act Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Proteksi Biodiversitas

19 Refuges, parks, preserves – How big should refuges be? – Where should they be? – McArthur & Wilson “Theory of Island Biogeography” colonization rate extinction rate (local) predicts number of species Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Proteksi Biodiversitas

20 Effect of island size Effect of island distance Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Proteksi Biodiversitas

21 McArthur & Wilson: “Teori Biogeografi Pulau” – Laju Kolonisasi – Laju Kepunahan (lokal) – predicts number of species Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Proteksi Biodiversitas

22 Biogeografi Pulau: Ukuran Pulau memprediksi jumlah spesies Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Proteksi Biodiversitas

23 Biogeografi Pulau – Everyplace is an island – Fragmentasi Habitat Smaller fragments hold fewer species Diunduh dari: facstaff.gpc.edu/~apennima/ENVS/Biodiversity.ppt ‎ Proteksi Biodiversitas

24 BIODIVERSITAS EKOSISTEM Diunduh dari: http://www.environmentabout.com/820/ecosystem-biodiversity-and-types-of-biodiversity ……………… 4/12/2012 ECOSYSTEM BIODIVERSITY implies the existence of different species within an ecosystem. It can also be defined as the degree of variations among the life forms in an ecosystem or planet. ECOSYSTEM DIVERSITY is the variety of different natural systems or ecosystems in a particular area. Examples of ecosystem diversity are deserts, forests, wetlands, rain-forests, marine ecosystems etc.

25 What is biodiversity? OED: “biodiversity Ecol., diversity of plant and animal life, as represented by the number of extant species” Ricklefs & Miller: Biodiversity includes a number of different levels of variation in the natural world: genetic, species, ecosystem Begon et al. “The term may be used to describe the number of species, the amount of genetic variation or the number of community types present in an area”. Tetapi.......… sebagian terbesar penelitian fokus pada diversitas spesies Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

26 Apakah Biodiversitas mempengaruhi fungsi-fungsi ekosistem ? Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

27 Konsekwensi fungsional dari Biodiversitas: Numbers and Kinds of Species Organismal traits Ecosystem Processes Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

28 Traits & Fungsi Ekosistem 1.Traits may mediate energy and material flow directly 2.Traits may alter abiotic conditions (limiting resources, disturbance, microclimate) Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

29 Ekspresi Trait ditentukan oleh: 1.Species richness 2.Species evenness 3.Species composition 4.Species interaction 5.Temporal and spatial variation Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

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31 The Ecosystem/Ecology Divide 1.Key ecosystem types in Arctic tundra show clear differences in key species and functional types 2.But at the ecosystem level there are clear patterns in the landscape irrespective of species composition 3.Bulk measures like LAI and foliar N are good descriptors of process rates 4.Dengan demikian, Apakah species sangat penting? Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

32 Kekayaan Species & Fungsi Ekosistem : Theory 1.If niches are complementary, adding species could increase process rates linearly 2.As niches overlap the response should saturate Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

33 Niche differentiation and productivity. a. A simple model — the 'snowballs on the barn' model — of niche differentiation and coexistence. The range of conditions in which each species can exist is shown with a circle, the position of which is defined by its centre. By randomly choosing locations for various numbers of circles (species), it is possible to calculate the effect of diversity on the 'coverage' of the heterogeneous habitat. The amount of such coverage is proportional to community biomass. b. Results of simulations (triangles) and of an analytical solution (solid curve) to the effects of diversity on community productivity for the snowballs on the barn model From: Tilman (2000), Nature. Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

34 (A)Dependence of 1996 aboveground plant biomass (that is, productivity) (mean and SE) on the number of plant species seeded into the 289 plots. (B)Dependence of 1996 above- ground plant biomass on the number of functional groups seeded into each plot. Curves shown are simple asymptotic functions fitted to treatment means. More complex curves did not provide significantly better fits From: Tilman et al. (1997) Science Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

35 Hypothesized mechanisms involved in biodiversity experiments using synthetic communities. Sampling effects are involved in community assembly, such that communities that have more species have a greater probability of containing a higher phenotypic trait diversity. Phenotypic diversity then maps onto ecosystem processes through two main mechanisms: dominance of species with particular traits, and complementarity among species with different traits. Intermediate scenarios involve complementarity among particular species or functional groups or, equivalently, dominance of particular subsets of complementary species. From: Loreau et al (2001) Science Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

36 Kemerataan Species 1.Human effects on species more commonly involve alteration of relative abundance than extinction 2.Little research on importance of evenness of function so far 3.Future richness experiments should include evenness effects Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

37 Komposisi Species Species mediate pathways of energy and material flow Examples: Introduced species can alter patterns of ecosystem processes Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

38 Species introduksi dapat mengubah pola proses-proses ekosistem 1.Introduction of N-fixing tree Myrica faya to N- limited Hawaiian forests led to 5-fold increase in N inputs 2.Dampak signifikan terhadap struktur dan fungsi hutan Vitousek et al. (1987) Science Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

39 Introduction of deep-rooted salt cedar (Tamarix sp.) to Mojave and Sonaran deserts resulted in: – Increased water accessed by vegetation – Increased surface litter and salts – Inhibited many native species, reduced biodiversity Berry (1970) Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎ Species introduksi dapat mengubah pola proses-proses ekosistem

40 Introduction of Agropyron cristatum, tussock grass, to US Great Plains – Reduced allocation to roots compared to native grasses – Soil N levels reduced, and 25% less total soil C compared to native prairie soil Christian & Wilson (1999) Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎ Species introduksi dapat mengubah pola proses-proses ekosistem

41 Introduction of Bromus tectorum, cheatgrass, to western US – Fire frequency increased by a factor of 10 in the >40 million ha it now dominates Whisenant (1990) Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎ Species introduksi dapat mengubah pola proses-proses ekosistem

42 Interaksi Species Mutualism Trophic interaction – Predation – Parasitism – Herbivory Competition Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

43 Mutualism 1.N-fixation in plant-microbe symbiosis 2.Plant-mycorrhizal associations 1.Both increase production and accelerate succession 3.Decomposition is driven by highly integrated consortia of microbes Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

44 STUDI KASUS Mycorrhizal fungal diversity determines plant biodiversity, ecosystem variability and productivity Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

45 van der Heijden 1998 Experiment 2 Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

46 Komunitas mikroba: Semakin beragam semakin efisien Soil microbial functional diversity (Shannon index H') and metabolic quotient (qCO 2 = soil basal respiration/soil microbial biomass) correlate inversely. A higher diversity in the organic plots is related to a lower qCO 2, indicating greater energy efficiency of the more diverse microbial community. The Shannon index is significantly different between both conventional systems (CONFYM, CONMIN) and the BIODYN system, the qCO 2, between CONMIN and BIODYN (P < 0.05). Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎ Maeder 2002

47 Interaksi Trophik Modify fluxes of energy and materials Influence abundance of species that control these fluxes – e.g., predator removal can lead to a cascade of ecological effects Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

48 (A) Changes in sea otter abundance over time at several islands in the Aleutian archipelago and concurrent changes in (B) sea urchin biomass, (C) grazing intensity, and (D) kelp density measured from kelp forests at Adak Island. Error bars in (B) and (C) indicate 1 SE. The proposed mechanisms of change are portrayed in the marginal cartoons- -the one on the left shows how the kelp forest ecosystem was organized before the sea otter's decline and the one on the right shows how this ecosystem changed with the addition of killer whales as an apex predator. Heavy arrows represent strong trophic interactions; light arrows represent weak interactions. Estes et al. (1998) Science Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

49 Interaksi Trophik 1.All types of organisms must be considered in understanding biodiversity effects 2.Interactions among species must be considered 3.Changes in interactions can alter traits expressed by species, so presence/absence of species is insufficient to predict impact Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

50 Biodiversity & Jasa Ecosystem 1.Ecosystem services are defined as the processes and conditions of natural ecosystems that support human activity and sustain human life 2.E.g., maintenance of soil fertility, climate regulation, natural pest control 3.E.g., flows of ecosystem goods such as food, timber and freshwater Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

51 Valuasi Biodiversitas 1.Techniques used include direct valuation based on market prices, and estimates of what individuals are willing to pay to protect endangered wildlife 2.Valuation of marginal losses that accompany specific biodiversity changes are most relevant to policy decisions 3.Predictions are highly uncertain Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎

52 Apa pengaruh diversitas tumbuhan thd proses-proses ekosistem? Plant community composition = IDENTITY Diversitas Tumbuhan: 1.Genetic 2.Population 3.Species 4.Functional group of species 5.Habitat Plant diversity = RICHNESS Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

53 Climate Relief (Topography) Parent material Time Organisms Ecosystem structure and function State Factors Ecosystem = (Cl, O, R, P, T) Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

54 Mengapa kita peduli ? Understand a state factor control over ecosystem variation: in space in time Memahami dampak aktivitas manusia: Habitat destruction and extinction Simplification through management Biological invasions Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

55 Variation in key plant traits can cause species to differ in their effects on ecosystem processes Trophic structure Biogeochemical cycles Disturbance regime Biophysical processes Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

56 Functional types are a useful simplification Life forms often make useful groups Groups of species that have a similar influence on an ecosystem process Relevant grouping depends on process of interest Makes it possible to represent aspects of diversity in models Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

57 Identitas Species : How does who ’ s there affect ecosystem processes? Siklus N …. … N fixation Space and time of N uptake Species of N used Turnover time and allocation Litter quality Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

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59  Growth  Quality litter  Nutrient mineralization +  Growth  Quality litter  Nutrient mineralization + Plant litter traits can reinforce site nutrient availability Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

60 Wedin and Tilman 1990 Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

61 Kekayaan Spesies = Species richness How does species number affect ecosystem processes? Is there an effect of diversity per se that is independent of identity? Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

62 Tilman et al. 1997 Production: +, saturating Changes in diversity have their largest effects at low diversity Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

63 Mekanisme-mekanisme 1. Complementary resource use:  Species = more complete resource use Niche differentiation, niche partitioning 2. Sampling effect:  Species =  probability of getting spp. with strong effects on processes How can we differentiate between these mechanisms? Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

64 Experiment: Menanam spesies secara Monokultur dan Campuran 1. Complementary resource use: Production in mixture >> production in monoculture Synergy: “ Overyielding ” 2. Sampling effect: Production in mixture = production in monoculture Few well-controlled empirical tests have manipulated richness independent of composition Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

65 Tilman et al. 1997 1.Functional diversity explained the greatest amount of variation in plant biomass 2.When functional diversity was included, species diversity had no effect Doesn’t matter how many species, only how many functional groups Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

66 Tilman et al. 1997 Effects of functional diversity were caused by presence or absence of key functional groups Productivity = C 4 grasses, legumes Plant %N = legumes Soil NO 3 - = C 4 grasses Overyielding was also observed: C 4 grasses yielded more in high then in low diversity treatments Diunduh dari: www.biology.ufl.edu/.../Diversity%20and%20ecosystems,%2011-3-10.p... ‎

67 References Chapin et al (2000) Consequences of changing biodiversity. Nature 405: 234-242 Tilman, Wedin and Knops (1996) Productivity and sustainability influenced by biodiversity in grassland ecosystems. Nature 379: 718-720 Naeem & Li (1997) Biodiversity enhances ecosystem reliability. Nature 390:507-509 Van der Heijden et al. (1998) Nature 396: 69-72 Constanza et al (1997) The value of the world's ecosystem services and natural capital. Nature 387: 253-260 Maeder et al (2002) Soil fertility and biodiversity in organic farming. Science 296: 1694-7 Diunduh dari: www.geos.ed.ac.uk/homes/mwilliam/Biodiversity1.ppt ‎