Stressors

sadhospitalMechanics

Feb 22, 2014 (3 years and 10 months ago)

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Stressors

A brief introduction to a
revolutionary approach to impact
management

In the beginning…

…We spoke of threats.
Common
threats
included:



Loss of resource quantity


Loss of resource quality


Disruption of a process



Loss of resource quantity:


Habitat loss


Reduced availability of a resource
(i.e., resource depletion as
opposed to removal)


Barriers to movement/restricted
access



Threats

Loss of resource quality:



Habitat degradation


Fragmentation



Threats

Disruption of processes:


Ecological
: cyclical processes
disrupted (e.g., hydrologic cycles,
fire regimes, natural succession)


Physiological:
hibernation,
estivation
, metamorphosis
processes disrupted


Biological: predation rates,
competition rates



Threats



Problem: One has
to know
the
species
to
comprehend
a
threat


Fragmentation


Habitat degradation


Loss of breeding habitat



The Problem

The Problem(s)

Population

dynamics

Prey Base

Dynamic

Inter
-
special
Competition

Basic Habitat
Need and
Function


Predation Rates

Then came stressors…

Stressors

Increased predation rates

Or

Wildlife
access to foodstuffs?



What would we tell a project proponent to
avoid, minimize, and mitigate?


A stressor is
a
clear descriptor that needs
little to no interpretation



Sedimentation


Soil compaction


Vegetation removal


Floating debris


Chemical contamination


Stressors


Active agents


Vehicle strikes


Trampling


Ensnarement


Electrocution



Physical agents


Chemical effluent


Sedimentation


Artificial light

Stressors



Breeding


Feeding


Sheltering

Conservation Needs

Resource


1

R2

R3

R4

Stressor

1

S2

S3

S4

Species

Need:

Breeding

Species have
three needs

(i.e., breeding, feeding, sheltering).

A need has
resources

associated with it (e.g.,
Breeding need:

forested
wetlands to nest in, riparian areas to rear young in).

The resources have
stressors

impacting them.




Individual


Habitat


Circumstance

Resources

Conservation Needs