REN R440 Lecture Notes - Lecture 6: Understory, Invertebrate, Keystone Species

• School: University of Alberta
• Department: Renewable Resources
• Course: REN R440
• Professor: Nadir Erbilgin

Document Summary

Can be applied to most situations where large numbers of trees die (forestry, insect outbreaks etc. ) Physical characteristics defining structure and altering microclimate: vertical stratification (can have different amounts of vertical structure, more continuous or just one layer), horizontal structure (gradients as you go through the forest), temperature, humidity (shading from veg, less evapotranspiration) Tissue chemistry and biomass contribute to ecosystem processes: nutrient cycling, primary productivity (accumulation of plant biomass, carbon sequestration increases with pp) Directly and indirectly impact ecosystem function (by supporting other species) High mortality severs ecological linkages between trees, other organisms and ecosystem functions, or if it doesn"t sever them, changes them down the road. Diseases can alter ecosystem functions, change the habitat for secondary species, will recover but not necessarily with the same species. Pathogens can be ecosystem engineers/ regulators, indirectly alter the resource availability for other species and alter the abiotic environment. Disease associated stress and mortality can help define species spatial distributions.