ENV100Y5 Lecture Notes - Lecture 2: Ecosystem Ecology, Biogeochemical Cycle, Nitrogen Cycle

• School: UTM
• Department: Environment
• Course: ENV100Y5
• Professor: Havelka, M.

Document Summary

Study of interactions among organisms and physical environment as an integrated system. Focuses on functions, processes, fluxes, biogeochemical cycles, etc. Ecosystem concept: (cid:862)we (cid:272)a(cid:374)(cid:374)ot sepa(cid:396)ate the(cid:373) (cid:894)organisms) from their special environment with (cid:449)hi(cid:272)h the(cid:455) fo(cid:396)(cid:373) o(cid:374)e ph(cid:455)si(cid:272)al s(cid:455)ste(cid:373) the s(cid:455)ste(cid:373)s a(cid:396)e the (cid:271)asi(cid:272) u(cid:374)its of (cid:374)atu(cid:396)e(cid:863) Ecosystems are dynamic, never stable, nested, and hierarchical. Inputs, outputs, feedback loops, resistance & resilience, emergent properties, biotic & abiotic components. Boundary between the biotic & abiotic components is often blurred. Closed system = energy arrives and leaves, (cid:373)atte(cid:396) does(cid:374)(cid:859)t a(cid:396)(cid:396)i(cid:448)e or leave. Open system = energy and matter arrives and leaves. Negative feedback (stabilizing): ex density dependent population regulation population tends to stay at a certain size and density. Positive feedback (one direction): ex loss of arctic ice, directing to one extreme. Autogenic recovery = recovering back to its original state all by itself. Unexpected interactions between compositions of an ecosystem.