PALLISER'S COUNTRY: Ecological Goals

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......		ECOLOGICAL GOALS
		Last modified September 8, 2002

Ecological Processes on the Grasslands

Conservation has been defined as the maintenance of healthy ecological processes across the landscape. What exactly are "ecological processes", and how do we know if they are healthy?

Ecological processes involve the interaction of living things with each other and their environment. Good health is generally taken to mean "sustainable over a long time frame" - hundreds of years. The following points summarize the types of interaction found in healthy grassland ecosystems. Participants may wish to add to this list.

Hydrologic cycle

grassland plants and animals are adapted to a relativly low amount of precipitation, generally less than 400 mm (15")

both living plants and organic litter slow the runoff and snow melt

groundwater is recharged, giving a stable water table

transpired water is often "recycled" through thunderstorms to other areas

floods and droughts of variable severity and frequency still influence the landscape

water is cleaned through absorption of materials and filtering

rivers maintain a balance between eroded banks and areas with stable vegetation

Nutrient cycle

nutrients are cycled quite quickly compared to forest ecosystems, and the average amount of biomass is stable or increasing
the physical environment provides growing conditions suitable for many species
a full and complex food web, including predators, supports an ecosystem with dynamic stability
interaction provides competition for living species
predation or human management removes excess population and recycles the nutrients
nutrients are dispersed across the landscape so they can be efficiently reused

Interaction with soil

the ecosystem includes a wide range of landforms and soil types
vegetation protects soil from water and wind erosion

Biodiversity

a wide and stable number of species use a variety of habitats
rare or locally extirpated species are given assistance to extend their ranges
species in "patchy" habitat are able to transfer genetic material at a natural rate
the vigourous native vegetation can resist the spread of invasive species
a moderate amount of disturbance (erosion, fire, heavy grazing, flood) ensures habitat for disturbance-adapted species while still supporting substantial areas of late-successional vegetation
introduced species make up a small (and decreasing) proportion of both the biomass and number of species

Fire

grass fires, either natural or managed, ensure a balanced impact across the landscape

Mitigation of pollution

vegetation and soil have a large capacity to absorb impurities from air and water
biodegradable waste products are kept at concentrations that can be absorbed by the environment before causing any harm
waste products that are not biodegradable are kept out of the grassland environment
native grassland is recognized as providing a significant carbon sink.

Determination of ecosystem health

Every aspect of an ecosystem constantly fluctuates. Specialists in many of these fields have determined how the situation has changed over time. In some cases, though, adequate base-line data has not yet been acquired. The landscape has generally been considered to be in a sustainable state prior to the introduction of the horse and gun to grassland residents. However, recent work is bringing to light the substantial impact that aboriginal people often had on the landscape. Even so, many present conditions clearly reflect the impacts of European settlement, and thereby suggest an unbalanced ecosystem.

A scientific means of determining if a certain region is "ecologically healthy" will probably never be achieved. Instead, we can look to the deep experience of long-time residents to understand the current trends. To these people, it will often be obvious if a region's health is deteriorating or thriving.

Making a difference

Many actions can be taken to relieve these impacts and bring about a healthier ecosystem. The preferable means of remediation is to strengthen the ecological process that has allowed the imbalance. While this may take more time than a technological solution, the results will be long lasting and may well bring other unintended benefits. It must be recognized that direct intervention will be required in some circumstances. Both types of actions have been well documented, and can be studied at many web sites.

This web site will not be suggesting particular actions. Instead, all stakeholders are encouraged to become familiar with their local grassland environment and to communicate with other interested parties. The local situation should be compared to the characteristics of a healthy ecosystem listed above. Existing and planned activities should be assessed with the principles of grassland conservation in mind, to ensure the actions make the best contribution to achieving the social and economic goals. It will quickly become evident that the diverse parties can agree on the need for some specific actions. The stakeholders are encouraged to proceed with these aspects, without trying to force agreement on all issues.

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ECOLOGICAL GOALS

Ecological Processes on the Grasslands

Determination of ecosystem health

Making a difference

ECOLOGICAL
GOALS