Protected Areas and in situ Conservation

Conserving plants in their natural habitat is often regarded as the mainstay of plant species conservation, but this involves more than the simple expedient of putting a fence around a few individuals. Most species, except those that are recent immigrants, have evolved in concert with other species and environmental factors such as climate, soils, and moisture. Even the simplest of ecosystems are rarely random selections of animals and plants thrown together, but rather complex networks of mutual interactions and interdependencies. Thus, conservation of individual species needs to take into account the communities within which species occur, its genetic makeup, the particular role they play in maintaining other parts of the system, and the species on which they themselves depend.

Communities include many feedback loops with a constant interplay of animals, plants, and physical factors, which in various ways reinforce processes that change through time. This raises important questions for management of communities and ecosystems: What happens when communities are stressed in various ways? What species losses can be expected on the basis of community structure? Are some kinds of communities more susceptible to catastrophes and species invasions than others? What kinds of species invade and what is their effect? Will the loss of one species cause other losses to cascade through the community, and if so, how far? Are there critical key species in the food web? If substantial numbers of species are lost, will they be recovered when original conditions are restored?

Comprehensive species conservation requires preservation of species throughout their complete geographic and habitat range and a consideration of patterns of variation. Conservation of plants must also take animals into account. Continued evolution will involve the interaction of both internal and external factors at a range of levels right down to the individual, and even the genome. As a result, there are a number of fundamental questions to consider when conserving species or special vegetation types in protected areas:

• Should protected areas be selected on the basis of strict biogeographic criteria?

• Can existing protected areas be upgraded to improve their conservation effectiveness?

• Are several small reserves better than one large one?

• The minimum viable population (MVP) debate—how large does the population have to be to be viable, and does MVP differ widely for different species?

• How is protection integrated with traditional uses of plants?

• How can plant conservation best be integrated with local people's development aspirations and wealth generation?

• How can we involve local stakeholders in the management of protected areas?

• How do we protect a mosaic of many habitat types which may be necessary for life history stages, or to conserve the full habitat needs of key pollinators and dispersers?

• Should priority be given to protection of representative areas, or of areas with high levels of species richness or unique vegetation types?

• What strategies will best protect genetic diversity within populations?

• If we simply protect representative ecosystems, are all species adequately protected along with them?

• What management and monitoring regimes should be implemented?

• Should there be routine provision for harvesting target plants in the protected area for sustainable use or for germplasm?

Most people accept the validity of these questions, but justifiably argue that one usually has to be pragmatic. Social and economic issues may be sensitive, especially where dense human habitation or questions of traditional use exist. Final boundary placement may have to be a compromise of financial and political factors, existing patterns of land ownership and use, and the practical availability of sites for preserves.

When people think of protected areas, the first thing that often comes to mind is the National Park System. These have wide international recognition as "jewels in the conservation crown" They enjoy a high public profile and are often large, preserving extensive ecosystems. But they may be too large to facilitate management of highly endangered species. They are also public areas, in that traditionally people have reasonably unconstrained access. On the other hand, strict nature reserves are well suited for conservation of individual species and smaller ecosystems. Yet, neither may meet the needs of relict stands of vegetation growing in highly modified, urban habitats, or the requirements of genetic resource conservation.

The UNESCO Man and the Biosphere programme have drawn attention in many countries to the need for a range of habitat types, from core areas that are close to a natural state, through transition zones, seres, and ecotones, to human-influenced lands. Particularly valuable is the concept of buffer zones bounding protected areas, and the range of mechanisms that can be used to protect nature values on production lands, including land management agreements and conservation covenants.

Sites not specifically protected for nature conservation may have high conservation value and reasonable permaneance. Examples include sacred sites such as churchyards and temples, railway or motorway embankments, lighthouse reserves, and military sites. In the United Kingdom burial grounds and churchyards are sometimes extremely valuable for protection of wildflowers that have all but disappeared from the countryside. There is an increasing need to think laterally when considering sites for conservation of natural vegetation and native species. Even sports and recreation grounds and racecourses are known to provide protection for populations of threatened plants. Management may not be simple on such sites. Competing uses have to be carefully meshed with conservation needs and there are likely to be conflicts that require compromise solutions.

Preserving biotic communities is not the same as preserving genes. Since communities are classified according to vegetation structure, and the dominant plant and animal keystone species, it is quite possible to preserve a community-type and still lose many species. It is also possible to preserve a species and lose genetically distinct populations. Although on-site conservation requires that biological diversity be considered as a whole—that is, in the form of intact communities—the type of conservation strategies employed and their outcome will depend on the particular focus. A protected area may concentrate on conserving a particular ecosystem, such as the Peat Swamp or Heath Forests of Malaysia, Terra Firme forest in Amazonia, or Scalesia forest on the Galapagos Islands. It may be focused on a particular and important tree species of one of those communities, such as Gonostylus bancanus found in the Peat Swamp Forests or Lippia growing in Scalesia forest. A protected area may also be established to conserve genetically distinct populations of such species, rather than the whole range of variation.

It is often assumed that conventional reserves to protect species and habitats are sufficient to conserve all aspects of biological diversity. This ignores the particular needs of genetic resource conservation concerned with crop relatives and wild species with economic value. The aim of genetic resource conservation is to maintain as many as possible of the genes or groups of genes found in these species in a representative array of combinations (Prescott-Allen and Prescott-Allen 1986).

A special kind of protected area is an in situ (on-site) genetic reserve, which is a location where wild genetic resources are conserved by maintaining gene pools of species in their natural habitat.

The emphasis is on species of known or potential economic value, and a necessary function is to provide for use of the gene pool. There are two important distinctions between management for gene pool conservation and management for other types of conservation. First, the unit of management is the gene pool rather than the species, community, or ecosystem. Second, provisions must be made for collection and sustainable use of plants from the reserve by bona fide breeders and research workers, and for supply of germplasm to ex situ gene banks.

These are the first steps for effective genetic resource conservation in natural habitats:

1. Select target taxa or region and undertake an ecogeographic survey to establish foci of genetic diversity for the taxa. This will determine where the reserve could be located within the region.

2. Survey potential sites for the genetic reserve and select the reserve site(s) based on scientific, economic and practical factors. Sites already under some form of protection, or in common ownership, are likely to be most easily converted to genetic reserves.

3. Establish working relationships between protected area managers, major users (such as plant breeders, geneticists, population biologists, and ethnobotanists), local traditional resource users, and the local community. This provides a range of expertise to carry out steps 2 and 4.

4. Complete a more detailed survey of population status, ecology, and life history of the target taxa within the genetic reserves.

5. Establish the management and monitoring regime for the genetic reserve that promotes the retention of genetic diversity within the reserve.

6. Use the routine genetic reserve monitoring to feedback into the reserve management regime.

7. Promote use of the reserve and the value resource by professional and traditional users, while ensuring use does not adversely impact genetic diversity of the target taxa.

8. Establish a link with ex situ conservation to ensure any unique genetic diversity is duplicated to ensure security.

An in situ gene bank may be a formally designated protected area such as a nature reserve. It may be a zone designated within a protected area that has other objectives, such as a national park. It may be a protected area specifically set aside with genetic resource conservation as its only purpose. Where there is competition among different users of land wanted for a gene bank, there may have to be careful selection so that adequate gene pools are protected in relatively few sites. Once organized, a national system of genetic reserve will include an array of different types of protected areas (Prescott-Allen and Prescott-Allen 1986):

1. Protected areas with many objectives, and some parts zoned for gene pool conservation. It is logical that existing protected areas are candidates for consideration as pilot genetic reserves.

2. Protected areas whose objectives do not permit artificial maintenance of seres (a developmental series of communities following in succession to a climax stage) or subcli-maxes, but instead conserve climax species through protection of ecosystems in their natural state.

3. Protected areas whose primary objective is gene pool conservation.

The distribution of protected areas should be such that they conserve at least one viable population of each major genetic variant of the target species. Protected populations must be sufficiently viable as to be self-sustaining, and so minimize the loss of genes that only occur in low frequency.

Those sites which have the highest numbers of target populations must be a priori for more detailed investigation and monitoring. It will be necessary to ensure that plant numbers are sufficient to maintain long-term populations, critical habitats are identified, essential associates such as pollinators and fruit dispersers are present, and other activities in the area do not jeopardize ex situ functions (MacKinnon et al. 1986). This is where it becomes essential to determine key biological parameters, such as minimum viable population size, natural, and induced fluctuations in the population, and interactions with co-existing species.

Between two areas of very dissimilar habitat or land use, there will be a transition zone where the habitats or land use interact as edge effects. Edge effects have two main consequences. In very small reserves, there is a risk of the whole reserve being subject to edge effects so that no undisturbed core remains; it becomes important to determine not only preferences of target species for core or non-core habitats, but also the preferences of inter-related organisms, such as pollinators. The concept has been particularly developed for the boundary between land grossly disturbed by people and predominantly natural habitat.

A widely adopted technique for minimizing edge effects and maintaining core areas is to establish buffer zones around reserves. Buffer zones are areas peripheral to national parks or reserves which have restrictions placed on their use to give an added layer of protection to the nature reserve itself, and to compensate villagers for the loss of access to strict reserve areas (MacKinnon et al. 1986).

There is considerable scope for protected areas and buffer zones for plant conservation to also help local people in a very practical way. Economic poverty of many tropical countries is aggravated by the adoption of new and inappropriate agro-silvicultural systems. Many traditional systems of agriculture (for example, multicrop and agroforestry systems) have evolved to minimize environmental impact. Their displacement can be disastrous. Protected areas are not only living laboratories for science and benchmarks against which to assess change; they can also offer valuable facilities, especially in buffer zones, for education and awareness programs, and for research into low-impact systems of land-use.

Local people may not have a profound understanding of modern conservation objectives, but there are many examples of traditional cultural practices that have themselves led to the protection of ecosystems and species. Where local practices such as type, timing, and intensity of harvesting are compatible with long-term conservation, management should aim to incorporate them. Other uses of plants by local people may have to be modified, especially where there are increasing demands on grazing land, fuelwood, or food plants. Necessary changes should be introduced at a pace that allows people to adapt and understand. Examples include progressing from wild harvest to sustainable cultivation of such crops as African ginger in South Africa and bulbs in Turkey. Common concerns provide a basis for dialogue to develop a system of management that will conserve plants and their environment, yet not alienate people. Local preference in employment is also an excellent way to integrate protected areas into the community and benefit people in the immediate vicinity. A high proportion of locally-generated wealth should be shown to directly benefit communities immediately adjacent to, and perhaps otherwise disadvantaged by, a protected area.

Managing protected areas does not come free. It can usually be assumed that costs of management are more likely to escalate than decrease. In too many instances, management has come to a standstill because it was assumed that necessary resources would become available or would not cost. Similarly, it is tempting to keep adding new protected areas into a system, but each time this happens it is necessary to budget not only for setting up a reserve (land purchase, fences, signs, etc.), but also for continued management. Cuts in research funding too often occur in those areas that are of most value to the conservation of plants, including population biology and monitoring. These are not seen as revenue earning, and monitoring in particular is open to criticism as being

"open-ended". Funding must be sufficient to carry out the minimum necessary activities to maintain a viable conservation program.

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