Outline Nursery surveys Nursery surveys Tree diversity and vegetation surveys Tree diversity and vegetation surveys
Diversity and agroecosystems What is diversity? What is diversity? Species accumulation curves Species accumulation curves Rank-abundance curves Rank-abundance curves Diversity profiles Diversity profiles Ordinations and species composition Ordinations and species composition Why study diversity? Why study diversity?
Diversity = number of species = richness Diversity = number of species = richness –Alpha diversity (site, farm, plot) –Gamma diversity (landscape) Site and landscape diversity 1 2 1 2 5 5 5 4 44 3 44
Linking richness to farm characteristics Species richness ~ farm characteristics Species richness ~ farm characteristics Regression models (GLM?) Regression models (GLM?)
Regression analysis Number of species Number of trees Distance from forest + Male-headed++ Female (de jure) + Farm size ++ Wealth-+ Years being head Age of head + Number of children + Education level Variation explained 24%20%
Richness and evenness Diversity = richness and evenness Diversity = richness and evenness Less diverseMore diverse richness evenness
Rényi diversity profiles Information on richness and evenness Information on richness and evenness Easier method to compare various diversities Easier method to compare various diversities Includes some commonly used diversity indices (Shannon, Simpson, Berger- Parker) Includes some commonly used diversity indices (Shannon, Simpson, Berger- Parker)
Same richnessSame evenness Almost same Shannon index Largest frequency of the dominant species A B C D
Ordination Diversity = differences in species composition Diversity = differences in species composition Ecological distance Ecological distance –0: same species –>0: more different in species composition Various distance measures Various distance measures Various techniques (constrained, unconstrained) Various techniques (constrained, unconstrained) –PCA (unconstrained) –CA (unconstrained) –PCoA (unconstrained) –NMS (unconstrained) –RDA (constrained: hypothesis) –CCA (constrained: hypothesis) –CAP (constrained: hypothesis)
Mt Kenya Tea-Dairy zone Map and Survey Routes N Coffee-Tea zone Main Coffee zone Marginal Coffee zone Sunflower-Maize zone Cotton zone Marginal Cotton zone Lower Midland Livestock Millet zone Lowland Livestock Millet zone Mt Kenya (5199m) KENYA Survey 1 Survey 2 Survey 3 Survey 4 Survey 5 Survey 6 Survey 7 Nairobi 020km40km
Agroecological zones at different altitudes in the Embu area Mt. Kenya (5199m) (>2070) (1400~1590) (1280~1460) (1280~1400) (1070~1280) (980~1220) (1770~2070) (1590~1830) (830~1130) (760~830) Tea- dairy zone Coffee- Tea zone Main Coffee zone Marginal Coffee zone Sunflower- Maize zone Marginal Cotton zone Cotton zone Lower Midland Livestock- Millet zone Lowerland Livestock- Millet zone Forest zone Altitude(m) Annual Rainfall(mm) (640~730) (700~900) (780~900) (900~1100) (960~1100) (1000~1250) (1200~1500) (1400~1800) (1750~2000)
Tea-Dairy Zone (1920m) Coffee-Tea Zone (1710m) Main Coffee Zone (1495m) Marginal Coffee Zone (1370m) Sunflower-Maize Zone (1340m) Cotton Zone (1175m) Marginal Cotton Zone (1100m) Lowland Livestock Millet Zone (795m) Individual species Lower Midland Livestock Millet Zone (980m) Name of zone (average altitude) euptir Cotton Zone Axis I Coffee-Tea Zone comsam tetrip sapell pinspp clejoh terman caedec vitken Main Coffee Zone Axis II Lower Midland Livestock Millet Zone eucsal vanmad cromeg brimic grerob mactet comemi manind cuplus erijap moralb perame cypbet cromac acamea prudom riccom carpap dovcaf macint titdiv tinaet acapol melaze casspe comcol commol rhunat sensin maysen solinc bouspe terbro cassia diccin lancam piltho strusaacrfra ozoinsmayhet ficsyc domrot acator acaata euppul balgla melvol jatcur acanil grebic gnilat cadfar citsin psigua catedu fausal capsep ormkir lanrivcomzey acahoc hibcal astaste eupfri scumyr penpar fluvir britai boscor delreg terpru comacu acasen albantcomafr comhab captom berdis theper haraby marlut Marginal Cotton Zone Tea-Dairy Zone Marginal Coffee Zone Sunflower-Maize Zone loneri Lowland Livestock Millet Zone grevil preres albama acamel datstr maetri leuleu sclbir jacmim clemyr eupcan maekir bosang physpp zancha balaeg CCA ordination diagram of species composition (108 major species) for eighty- three plots in the Embu area. Plot symbols represent main agro-ecological zone. Nine zones in the area are circled individually in the diagram
Redundancy Analysis – differences in species composition of hedges in W-Kenya
Why conduct nursery or vegetation surveys? Baseline for impact assessment Baseline for impact assessment Planning of diversification Planning of diversification –Addition –Replacement –Substitution –Management
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