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GRADIENT: Himalayan elevation gradient NICHE: temperature niches Richness Endemics Life forms. But first: do communities exist?. A short answer after a long debate: No. Compositional variation in nature tends to be gradual. How can we analyse species composition?.
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GRADIENT: Himalayan elevation gradient NICHE: temperature niches Richness Endemics Life forms
A short answer after a long debate: No. Compositional variation in nature tends to be gradual.
How can we analyse species composition? Within some defined environment or area we sample a number of plots and register the species present
The temperature nicheHabitat is where plant live, e.g. in oak forest, on open slopes, at rhododendron trees, etcDistribution range is where on a geogrphical one may find the target species
high Alpine Tundra Elevation low Temperated Forest Northern Coniferous Forest Arctic Tundra Elevation gradient variation in temperature and correlated variables e.g. soil Montane Coniferous Forest Deciduous Forest
High-land sp Mid elevation Low-land sp M ASL ELEVATION GRADIENT SPCECIES OCCURE AND DISAPEAR
ELEVATIONE RANGEELEVATION CONVERTED TO TEMPERATURE EXAMPLES: RHODODENDRON IN THE HIMALAYAS
Concepts: realized and potentialniche Realized climate niche = the average climate conditions where the species are growing in nature Potential climate niche = the climate conditions where the (fundamental) species are able to grow without interference from other organisms abundance temperature
high Alpine Tundra Elevation low Subtropical Forest Northern Arctic Tundra Elevation gradient in temperature lapse rate= decrease 0.5 degrees Celsius each 100 elevation meter Montane Coniferous Forest Deciduous Forest
INTERPOLATION : ASSUMING ALL SPECIES ARE PRESNET IN ALL 100M INTERVALS BETWEEN LOWER AND UPPER ELEVATION LIMIT This gives total number of specie in all different elevation bands from 100 m to 6000 m a.s.l.
INTERPOLATION : ASSUMING ALL SPECIES ARE PRESNET IN ALL 100M INTERVALS BETWEEN LOWER AND UPPER ELEVATION LIMIT This gives total number of species in all different elevation bands from 100 m to 6000 m a.s.l. This can be done for different life forms, such as ferns,trees or total number of endemics and total number of species
Species richness Elevation Tree species richness patterns • Unimodal relationship between tree species richness and elevation. • Maximum tree species found between 900 and 1000 m.
Mountain Biomes • “Islands” = isolation= speciation, polyploidy => endemics
Interpolated species richness in the Himalayas Plateau MASL
Is Gamma diversity able to predict the pattern of Alpha diversity along an elevation range? Ole R. Vetaas, M. Panthi, & K. Shrestha, IE Maaren Centre for Development Studies, University of Bergen, Nygaardsgt. 5, N-5015 Bergen, NORWAY. Central Department of Botany, Tribhuvan University, P.B. 5927 Kathmandu, Nepal.
high Ice & rock Alpine Tundra Elevation low TROPICAL FOREST Northern Coniferous Forest Arctic Tundra Elevation Gradient Montane BETULA &…… Coniferous Forest EVERGREEN OAK-RHODODENDRON-Forest Deciduous Forest TROPICAL FOREST
high Ice & rock Alpine Tundra Elevation low TROPICAL FOREST Northern Coniferous Forest Arctic Tundra elevation gradient Montane BETULA &…… 4000 m asl Coniferous Forest EVERGREEN OAK-RHODODENDRON-Forest Deciduous Forest 2000 m asl TROPICAL FOREST
high Ice & rock Alpine Tundra Elevation low TROPICAL FOREST Northern Coniferous Forest Arctic Tundra elevation gradient Montane BETULA &…… Coniferous Forest EVERGREEN OAK-RHODODENDRON-Forest Deciduous Forest TROPICAL FOREST
Rh. arboreum spp. arboreum Rh. arboreum spp. cinnamomeum
high Ice & rock Alpine Tundra Elevation low TROPICAL FOREST Northern Coniferous Forest Arctic Tundra elevation gradient Montane BETULA &…… Coniferous Forest EVERGREEN OAK-RHODODENDRON-Forest Deciduous Forest TROPICAL FOREST
Sampling: 5 plots (10m x10m) in each 100m elevation on N- and S- aspects of the valley Area: Manag 3200 – 4000 masl
high Ice & rock Alpine Tundra Elevation low TROPICAL FOREST Northern Coniferous Forest Arctic Tundra elevation gradient BETULA Montane BETULA &…… Coniferous Forest EVERGREEN OAK-RHODODENDRON-Forest Deciduous Forest TROPICAL FOREST
ANNAPURNA RANGE MONSOON
Diversity concepts • Two of late R.H. Whittakers diversity concepts • Alpha diversity number of species in community, i.e. # species per area • (point-alpha) • Gamma diversity not well-defined concept, high alpha and high beta produce high gamma.
Gamma diversity? • Lomolino defined Gamma diversity as total number of species in certain elevations zone in a mountain range. • Similar to the concept of Species pool, which is indicating the potential number of species that could be found in a given area.
Interpolated species richness in the Himalayas GAMMA diversity~ species pool We used data on elevation ranges in the Enumeration of flowering plants in Nepal (Hara et al., 1978;Hara & Williams, 1979; Hara et al., 1982) to describe the pattern of species richness along the elevation gradient. MASL
Interpolated species richness in the Himalayas Plateau MASL
Alpha diversity number of species per 100 square metre • Species richness was recorded from 350 10m x 10m plots: 2000 - 4000 m asl Average species richness (alpha diversity) for each 100 m elevation zone Sources: Vetaas, Maaren, KB Shrestah, M Panthi, and Ohasi H. (The Flora of eastern Himalaya)
Species pool for each 100m elevation interval = Gamma diversity
Average alpha diversity in 100 square metre plots for each 100m elevation interval