Rangelands after Exam 2 Content

social ecological system

framework for understand complex rangeland dynamics and identifying interventions that can increase rangeland sustainability

self-reinforcing or amplifying

positive feedback loop

self-regulating, or stabilizing

negative feedback loop

resilience

the capacity of a system to absorb disturbance and reorganize so as to retain essentially the same function, structure, identity, and feedbacks

scale

the spatial and temporal dimension of natural phenomena

non-resilient SES

A _____ may change or lose components and
functionality when an unusual change, or perturbation,
occurs in either the social or the ecological subsystem

resilient SES

will not only maintain function, but may also benefit from disturbance by reorganizing to further increase resilience.

provisioning services

the products obtained from ecosystems that can be directly harvested, and have a market value

regulating services

the benefits that humans receive from regulating ecosystem processes

cultural services

nonmaterial benefits that humans obtain from ecosystems

supporting services

necessary for the production of all other ecosystems services; not directly used by people

win-win interactions

synergistic interactions among different ecosystem services; one ecosystem service increases, so does the other

trade-off interactions

antagonistic interaction between ecosystem services; one ecosystem service increases, the other decreases

successional plant theory

Fredrick Clements; directional change of plant communities over time

primary succession

begins on rocks surfaces with no soil

secondary succession

begins after a disturbance that leaves soil on the site; soil exists, along with some components from previous vegetative community

climax

the end point of succession

pioneer community

start point of succession

poor, excellent

as vegetation community goes from pioneer to climax, range condition goes from _____ to _____

high, low

As vegetation community goes from pioneer to climax, grazing intensity goes from ____ to _____

managing for the middle

This grazing intensity (stocking rate) practice is the economic optimum

non-linear changes in vegetation community

shortcoming of plant successional model for rangeland management

non-equilibrium ecology and resilience theory

basis for rangeland management in the late 1980s through present

alternative stable state

differing arrangements of an ecosystem’s characteristics, such as its functions processes, components, and interrelationships.

stable states, states, regimes, and equilibrium points

other ways of referring to alternative stable states

state-and-transition models

a means to organize and communicate information about ecosystem change as a basic for management; organized as a collection of all recognized or anticipated stable states that individual ecological sites may support

transient dynamics

changes within a plant community driven by succession, grazing, management, drought, fire, climate fluctuations, etc.

state transitions

transitions from one state to another and the mechanism driving transitions