Class

Article

College

S.J. & Jessie E. Quinney College of Natural Resources

Faculty Mentor

Jim Lutz

Presentation Type

Oral Presentation

Abstract

A distinct challenge facing ecologists is to understand individual and interactive effects of climate, edaphic characteristics, and biotic relationships on forest ecosystems in order to anticipate and adapt to environmental change. Forest demography is influenced by many ecological processes, including gap-creating to stand-replacing disturbances, pest and pathogen attack, herbivory, shading and crowding, resource competition, heavy metal toxicity, and direct climate impacts. However, a comprehensive assessment of forest demographic responses to these ecological processes can be difficult to accomplish, as seasonal and inter-annual climate variability can interact with biotic and edaphic characteristics to impact individual tree mortality, recruitment, and growth – a complex and, thus, largely understudied phenomenon. We investigate these relationships in the Wind River Forest Dynamics Plot, a 27.2-ha permanent research site located in an approximately 500-yr old forest within the T.T. Munger Research Natural Area of the Gifford Pinchot National Forest in Washington State, USA. We model vital rates, including rates of agent-specific tree mortality, as functions of neighborhood structure and composition along gradients of soil resources and topography, and assess these relationships over a six-year timespan to quantify the direct and indirect effects of climatic water deficit and snowpack variability on tree vital rates. Our data support the interpretation that interactions across multiple scales must be considered prior to interpreting main effects in isolation, as climatic, edaphic, and biotic processes indeed modify each other’s effects - in several cases, these interactions resulted in complete reversals or nullification of main effects. We underscore the point that future research must endeavor to capture the complexity of ecological interactions in order to most accurately understand, and therefore, most appropriately respond, to global change.

Location

Room 204

Start Date

4-12-2018 3:00 PM

End Date

4-12-2018 4:15 PM

Share

COinS
 
Apr 12th, 3:00 PM Apr 12th, 4:15 PM

Climate and soil nutrients jointly determine the strength of density-dependent interactions in an old-growth temperate forest

Room 204

A distinct challenge facing ecologists is to understand individual and interactive effects of climate, edaphic characteristics, and biotic relationships on forest ecosystems in order to anticipate and adapt to environmental change. Forest demography is influenced by many ecological processes, including gap-creating to stand-replacing disturbances, pest and pathogen attack, herbivory, shading and crowding, resource competition, heavy metal toxicity, and direct climate impacts. However, a comprehensive assessment of forest demographic responses to these ecological processes can be difficult to accomplish, as seasonal and inter-annual climate variability can interact with biotic and edaphic characteristics to impact individual tree mortality, recruitment, and growth – a complex and, thus, largely understudied phenomenon. We investigate these relationships in the Wind River Forest Dynamics Plot, a 27.2-ha permanent research site located in an approximately 500-yr old forest within the T.T. Munger Research Natural Area of the Gifford Pinchot National Forest in Washington State, USA. We model vital rates, including rates of agent-specific tree mortality, as functions of neighborhood structure and composition along gradients of soil resources and topography, and assess these relationships over a six-year timespan to quantify the direct and indirect effects of climatic water deficit and snowpack variability on tree vital rates. Our data support the interpretation that interactions across multiple scales must be considered prior to interpreting main effects in isolation, as climatic, edaphic, and biotic processes indeed modify each other’s effects - in several cases, these interactions resulted in complete reversals or nullification of main effects. We underscore the point that future research must endeavor to capture the complexity of ecological interactions in order to most accurately understand, and therefore, most appropriately respond, to global change.