Abstracts |
The soil environment is likely the most complex biological community. Soil
organisms are extremely diverse and contribute to a wide range of ecosystem services that are
essential to the sustainable function of natural and managed ecosystems. The soil organism
community can have direct and indirect impacts on land productivity. Direct impacts are those
where specific organisms affect crop yield immediately. Indirect effects include those provided
by soil organisms participating in carbon and nutrient cycles, soil structure modification and
food web interactions that generate ecosystem services that ultimately affect productivity.
Recognizing the great biological and functional diversity in the soil and the complexity of
ecological interactions it becomes necessary to focus in this paper on soil biota that have a
strong linkage to functions which underpin 'soil based' ecosystem services. Selected organisms
from different functional groups (i.e. Microsymbionts, decomposers, elemental transformers, soil
ecosystem engineers, soil-borne pest and diseases, and microregulators) are used to illustrate
the linkages of soil biota and ecosystem services essential to life on earth as well as with
those associated with the provision of goods and the regulation of ecosystem processes. These
services are not only essential to ecosystem function but also a critical resource for the
sustainable management of agricultural ecosystems. Research opportunities and gaps related to
methodological, experimental and conceptual approaches that may be helpful to address the
challenge of linking soil biodiversity and function to the provision of ecosystem services and
land productivity are discussed. These include: 1) integration of spatial variability research in
soil ecology and a focus on 'hot spots' of biological activity, 2) using a selective functional
group approach to study soil biota and function, 3) combining new and existing methodological
approaches that link selected soil organisms, the temporal and spatial dynamics of their
function, and their contribution to the provision of selected 'soil based' ecosystem services, 4)
using understanding about hierarchical relationships to manage soil biota and function in
cropping systems, 5) using local knowledge about plants as indicators of soil quality, remote
sensing and GIS technologies, and plant-soil biota interactions to help understand the impacts of
soil biota at landscape scale, and 6) developing land quality monitoring systems that inform land
users about their land's ecosystem service performance, improve capacities to predict and adapt
to environmental changes, and support policy and decision-making. (C) 2007 Elsevier B.V. All
rights reserved.
|