14 research outputs found
Impact of Forest Seral Stage on use of Ant Communities for Rapid Assessment of Terrestrial Ecosystem Health
Bioassessment evaluates ecosystem health by using the responses of a community of organisms that integrate all aspects of the ecosystem. A variety of bioassessment methods have been applied to aquatic ecosystems; however, terrestrial methods are less advanced. The objective of this study was to examine baseline differences in ant communities at different seral stages from clear cut to mature pine plantation as a precursor to developing a broader terrestrial bioassessment protocol. Comparative sampling was conducted at nine sites having four seral stages: clearcut, 5 year recovery, 15 year recovery, and mature stands. Soil and vegetation data were also collected at each site. Ants were identified to genus. Analysis of the ant data indicated that ants respond strongly to habitat changes that accompany ecological succession in managed pine forests, and both individual genera and ant community structure can be used as indicators of successional change. Ants exhibited relatively high diversity in both early and mature seral stages. High ant diversity in mature seral stages was likely related to conditions on the forest floor favoring litter dwelling and cold climate specialists. While ants may be very useful in identifying environmental stress in managed pine forests, adjustments must be made for seral stage when comparing impacted and unimpacted forests
Variation in horizontal zooplankton abundance in mountain lakes: shore avoidance or fish predation?
Ecosystem health and integrity?
The concepts of ecosystem health and ecosystem integrity are discussed and found to be ecologically inappropriate. The phrase ecosystem health is based on an invalid analogy with human health requiring acceptance of an optimum condition and homeostatic processes maintaining the ecosystem at a definable optimum state. Similarly, ecosystem integrity is not an objective, quantifiable property of an ecosystem. Health and integrity are not inherent properties of an ecosystem and are not supported by either empirical evidence or ecological theory. Key words: ecosystem health, ecosystem integrity, ecosystem, management, sustainability. </jats:p
Selection of an Aquatic Indicator Species to Monitor Organic Contaminants in Trophically Simple Lotic Food Webs
Mortality, Preference, Avoidance, and Activity of a Predatory Leech Exposed to Cadmium
Harmonisation of methods for the assessment and reporting of forest health in Australia — a starting point
The harmonisation of a sub-set of forest health attributes suitable for aggregating, through scales ranging from individual trees to the operational forest management unit and up to the national level, has been achieved in countries such as the USA and Canada. In Australia, however, data collected on forest health is currently obtained on an ad hoc basis with only a small proportion of the national forest estate actually having been assessed. National guidelines are required for the objective assessment of a set of indices relating to forest health before Australia is in a position to report adequately on forest ecosystem health and vitality as recommended by the (Australian) Montreal Process Implementation Group. Obtaining these indices must be an affordable process that fulfills forest health reporting requirements for a range of national, state and regional reporting commitments such as the State of the Forests Reports and for the Regional Forest Agreements review process. In addition, it is envisaged that the indices will contribute to the verification process for the forest health and vitality criterion described in the Australian Forestry Standard for certification of sustainable forest management practices.
Tree crown condition is proposed as a key attribute of forest health and it is amenable to rapid standardised assessment. Four measures are proposed which have the potential to provide consistent core data on tree crown condition. Adoption of these indices will depend on the assessments being cost effective and consistent, and the results being meaningful for a range of applications. To facilitate this process an illustrated field manual has been published, providing guidance for standardised assessment methods. Initially the scope of the manual is limited, focusing on the assessment of eucalypt tree crown damage. If it proves successful, the number of indicators relating to forest health monitoring could be increased
