Human Resource Use Human Values Attitudes Sociopolitical Human

  • Slides: 45
Download presentation
Human Resource Use Human Values & Attitudes (Socio-political)

Human Resource Use Human Values & Attitudes (Socio-political)

Human Land Use Practices 1) Agriculture 2) Suburban Development Let’s pick on Indiana: •

Human Land Use Practices 1) Agriculture 2) Suburban Development Let’s pick on Indiana: • • 97% of land in state = privatelyowned In central Indiana, • 70+% of land in row crop • <10% in forest • Urban sprawl intensifying

Human Impacts Ecosystem simplification: elimination of species from food webs via human alterations to

Human Impacts Ecosystem simplification: elimination of species from food webs via human alterations to land Example: vertebrate communities in ag. landscapes

Intensive Agriculture & Clean Farming

Intensive Agriculture & Clean Farming

Timber Extraction & Fragmentation

Timber Extraction & Fragmentation

Formation of Terrestrial “Islands”

Formation of Terrestrial “Islands”

Oceanic Island = Terrestrial Island ? ? ?

Oceanic Island = Terrestrial Island ? ? ?

Species-Area Relationship S = c. Az S = # of species A = island

Species-Area Relationship S = c. Az S = # of species A = island area • Positive correlation between island size & number of species • Applies to terrestrial “islands” also

Island Biogeography • equilibrium model suggesting that the number of species occurring on an

Island Biogeography • equilibrium model suggesting that the number of species occurring on an island represents a balance between immigration (in) and extinction (out) • Robert Mac. Arthur & E. O. Wilson

Habitat Fragmentation • Process of breaking contiguous unit into smaller pieces; area & distance

Habitat Fragmentation • Process of breaking contiguous unit into smaller pieces; area & distance components • Leads to: < remnant patch size > edge: interior ratios > patch isolation < connectivity • Community & Ecosystem processes altered

Formation of Terrestrial “Islands”

Formation of Terrestrial “Islands”

#patches Patch isolation Patch size Edge

#patches Patch isolation Patch size Edge

What about aquatic systems?

What about aquatic systems?

What about aquatic systems? Con. Bio 12(6)

What about aquatic systems? Con. Bio 12(6)

Increased Edge Habitat

Increased Edge Habitat

Increased Edge Habitat

Increased Edge Habitat

Habitat Fragmentation • First-Order Effects: fragmentation leads to change in a species’ abundance and/or

Habitat Fragmentation • First-Order Effects: fragmentation leads to change in a species’ abundance and/or distribution • Higher-Order Effects: fragmentation indirectly leads to change in a species abundance and/or distribution via altered species interactions

Habitat Fragmentation • area-sensitive species: species that require minimum patch size for daily life

Habitat Fragmentation • area-sensitive species: species that require minimum patch size for daily life requirements • Edge effects: influence of factors from outside of a patch

Edge Effects • Habitat surrounding a patch can: - change abiotic conditions; e. g.

Edge Effects • Habitat surrounding a patch can: - change abiotic conditions; e. g. , temp. - change biotic interactions, e. g. , predation Example of nest predation = edge effect of approximately 50 m into forest patch But can extend 100’s of meters…. maybe km’s

Edge Effects • How does patch size (in a landscape) & shape affect amount

Edge Effects • How does patch size (in a landscape) & shape affect amount of edge? • Groups – give me a mathematical example with forested landscapes that have timber extraction via clearcutting

Exponential vs. Logistic No DD All populations same No Spatial component

Exponential vs. Logistic No DD All populations same No Spatial component

Incorporating Space Metapopulation: a population of subpopulations linked by dispersal of organisms • subpopulations

Incorporating Space Metapopulation: a population of subpopulations linked by dispersal of organisms • subpopulations separated by unsuitable habitat • subpopulations differ in population size & distance between

Metapopulation Model p = habitat patch (subpopulation) c = colonization e = extinction

Metapopulation Model p = habitat patch (subpopulation) c = colonization e = extinction

Another Population Model Source-sink Dynamics: grouping of multiple subpopulations, some are sinks & some

Another Population Model Source-sink Dynamics: grouping of multiple subpopulations, some are sinks & some are sources Source Population = births > deaths = net exporter Sink Population = births < deaths

Source-sink Dynamics >1 <1

Source-sink Dynamics >1 <1

Source-sink Dynamics

Source-sink Dynamics

Corridors

Corridors

Who Cares? Why bother discussing these models? Metapopulations & Source-sink Populatons highlight the importance

Who Cares? Why bother discussing these models? Metapopulations & Source-sink Populatons highlight the importance of: • habitat & landscape fragmentation • connectivity between isolated populations • genetic diversity

Vancouver Island marmot (Marmota vancouverensis) ~100 left Isolated from hoary and Olympic marmots

Vancouver Island marmot (Marmota vancouverensis) ~100 left Isolated from hoary and Olympic marmots

Vancouver Island marmot (Marmota vancouverensis) Natural tree succession

Vancouver Island marmot (Marmota vancouverensis) Natural tree succession

Vancouver Island marmot (Marmota vancouverensis) • Logging – disjunct patches - max. dispersal =

Vancouver Island marmot (Marmota vancouverensis) • Logging – disjunct patches - max. dispersal = 7 km • Climate • Prey-Predator Dynamics

Differential Sensitivities to Habitat Alteration • Niche breadth (diet & habitat) – inverse relation

Differential Sensitivities to Habitat Alteration • Niche breadth (diet & habitat) – inverse relation • Range periphery = more sensitive (W & N) • Body size = mobility (allometric relation) • Social and territorial behavior (limited K) Swihart et al. 2003

Ways to Manage 1) Featured Species Mgt – single species – particular purpose –

Ways to Manage 1) Featured Species Mgt – single species – particular purpose – e. g. , white-tailed deer – could also include “umbrella species” and “flagship species” or “sensitive species”

Ways to Manage 2) Species Richness Mgt – maintain diversity and certain # of

Ways to Manage 2) Species Richness Mgt – maintain diversity and certain # of each species (follow MVP concept) 3) Indicator Species Mgt – use a species (or group of species) to monitor environmental conditions – not necessarily managing for these spp. – bioindicators, biosentinels, “canary in coal mine”

Ways to Manage 4) Guild Mgt or Life-Form Mgt – grouping of species based

Ways to Manage 4) Guild Mgt or Life-Form Mgt – grouping of species based on use of same type of resources (e. g. , foraging guilds)