18 terms

Spatial & Temporal Patterns of Biodiversity (2.1)

Effect of higher latitudes
Linear decrease in species number e.g. birds, trees
Differences of lower latitudes
More Sunshine, higher Temperatures, Seasonal variation in rainfall
Effect of rainfall in tropical forest
10x number of vascular plants with 2000mm than 750mm annually
Effect of altitude
Species richness Declines - particularly over 4000m
Differences of higher altitudes
1/ Cloudier 2/ lower Evapotranspiration 3/ lower Temperatures 4/ higher Rainfall 5/ Windier
Effect of solar energy between latitudes
10x number of tree species with 26C compared to 13C - e.g. Ghana, France
Measures of incoming energy
1/ Potential evapotranspiration 2/ Actual evapotranspiration
Potential evapotranspiration
Based on Temperature & measures the amount of water that Could be evaporated
Actual Evapotranspiration
Actual amount of water evaporated
Species richness correlation
PET & AET e.g birds, mammals, amphibians, reptiles
Effect of High energy & Variable rainfall
Species richness is Variable
Effect of high energy & high rainfall
Species richness is high
Effect of Strong Seasonality
Energy or water availability means shorter growing season
Effect of Productivity
Correlation often with species richness
Effect of fertilisers & pollutants
1/ Increase of Biomass 2/ Decline in less competitive species
Effect of predation & herbivory
Reduction in biomass, competitive species decline (e.g. rabbits prior myxomatosis)
Effect of early succession
Initially very Low species richness increasing
Effect of Later Succession
Rate of species immigration balanced by species loss - i.e. steady-state