PARENT SESSION
Symposium 9: Functional Significance of Mountain Biodiversity.
Organized by: WD Bowman
Tuesday, August 3, 1:30 PM to 5:00 PM, Oregon Ballroom 204.

Linkages between aboveground and belowground biodiversity in mountain ecosystems.

Bardgett, Richard ¹, ¹ Institute of Environmental and Natural Sciences, Lancaster, Lancashire, United Kingdom

ABSTRACT- It is becoming increasingly recognised that feedbacks between the producer and decomposer subsystems operate as a major driver of ecosystem functioning. In this talk, I will discuss recent advances in our understanding of the functional importance and nature of links between these two subsystems in mountain ecosystems, and of the potential roles of plant and soil diversity in their operation. The importance of these feedbacks will be illustrated using selected examples from studies done in mountain regions of the United Kingdom, especially in grassland and regenerating woodland of the Scottish Highlands. First, I will illustrate the general importance of soil organisms and their interactions as regulators of plant nutrient supply and nutrient retention in high mountain ecosystems. Specifically, I will show how soil microbes act as major sinks for nutrients in these nutrient limited ecosystems and how partitioning of nutrients between the plant and microbial pool varies temporally. I will then consider how variations in the diversity and composition of the plant community might impact on these processes of nutrient cycling, and how variations in the diversity of microbial-feeding soil animals might influence plant nutrient supply through their impact on soil microbes. Finally, the importance for nutrient cycling of these aboveground-belowground linkages will be considered in the context of other components of mountain ecosystems, namely large mammalian herbivores.

Key words: nitrogen cycling , soil ecology , herbivores, biodiversity