Download presentation
Presentation is loading. Please wait.
Published byDoreen Tate Modified over 9 years ago
2
Community Collection of species populations Members from most kingdoms Linked in a web Mainly predator/prey Environment & habitat / Dominant species Lake/grassland Sizes
3
Habitats and Niches Habitat: A collection of niches Habitat Physical space where an organism lives Microhabitats Niche The unique position occupied by a particular species in a community – ecological role Each niche unique Occupy overlapping BUT different niches Fundamental vs. realized niche Resource partitioning Darwin’s finches
4
Darwins’ Finches
5
Patchiness Distribution patterns Random Aggregated Conditions & resources not evenly distributed Temporal variability Intraspecific & interspecific competition Events Gradient Regular
6
Plankton patchiness Horizontal, temporal & vertical variability Physical - Water movements Biological – plankton related Light – dark cycle Gamete concentration Predator – prey interactions
7
Trophic interactions and productivity Primary producers, consumers, decomposers Rule of 10% Different communities w/ different# of trophic levels NPP
8
Net Primary Production
9
Trophic interactions and productivity Guilds Overlapping niche requirements Keystone species Limpets Dominant Numerical or biomass abundance Opportunistic species, specialization, generalists
10
Measuring Productivity 6CO 2 + 6H 2 O C 6 H 12 O 6 (glucose) + 6O 2 Increase in biomass over a fixed time period NPP Plankton
11
Chylorphyll abundance Secondary production Measuring Productivity
12
Comparative Ecosystem Productivity Productivity determinants Light, temperature, rainfall, nutrients Tropics, higher latitudes, deserts Photosynthetic efficiency 1-2 % in terrestrial ecosystems – 0.5 % in aquatic habitats Conditions for plant growth not met More secondary production in oceans Detritivores
13
Trophic Interactions & Pollution Material transfer Minerals, vitamins etc. Pollutants Heavy metals, organic chemicals, some light elements Bioconcentration Biomagnification Biotransformation Mercury methyl mercury
14
Mercury Pollution Minimata disease, brain damage, kidney damage etc. Organic methyl mercury Bioconcentration & Biomagnification
15
Succession The change in composition and form of vegetation Immature mature/self-sustaining Primary Succession Pioneer species Xerarch vs. hydrarch succession Secondary succession Climax community
16
Xerarch vs. hydrarch succession
17
Succession
18
Biodiversity Species & genetic & ecosystem diversity biodiversity Ecological diversity Species diversity Genetic diversity Species richness vs. species diversity Tropical forests, coral reefs and tropical lakes Genetic diversity Habitat destruction, pollution and agricultural practices
19
Stability and Resilience Stability – environmental change Persistence, constancy, resilience High diversity = high stability? Tropical rainforest vs. grasslands
20
Biogeography Study of the distribution of organisms Historical & Ecological Vicariant and dispersal distribution Endemic taxa Six major zones
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.