Separating stressor influences from environmental variability: eight case studies from aquatic and terrestrial ecosystems

Book · Mon Dec 03 04:00:00 EST 2001

OSTI ID:901487

Luoma, Samuel N; Clements, Will; Gerritsen, Jeroen; Hatch, Audrey; Jepson, Paul; Reynoldson, Trefor; Thom, Ronald M

It can be difficult to unambiguously establish the influences of a particular stressor or group of stressors in a complex ecosystem, except, perhaps, when the effects are extreme (Luoma and Carter, 1991). Yet this is a critical problem we face when attempting to understand the influences of human activities on ecosystems. Single experiments or studies are rarely adequate to establish cause and effect in complex ecosystems, and many of the individual approaches available to demonstrate stressor effects have important inadequacies. A multi-faceted body of work is usually at the center of most examples where stressor effects are explained. In this chapter seven case studies are presented where effects or influences of multiple stressors were explained and separated from natural variability. The goal of this chapter is to demonstrate that identification of stressor effects is tractable, although not necessarily simple; and to illustrate some specific strategies that have worked. We also present one case study where the quest for cause and effect is just beginning, to illustrate the range of challenges involved as a body of work begins to be established. The examples are from several different fields of ecology, they cover a variety of scales and a mix of disciplines.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 901487
• Report Number(s): PNWD-SA-5435
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ECOLOGY
ECOSYSTEMS
TERRESTRIAL ECOSYSTEMS
kelp forests
long-term impacts
multiple stressors