摘要:

Wildlife resources under the protective custodianship of skilled managers can thrive and sustain important revenues. Such custodianship is generally lacking among communal rural societies in Africa because of land use policies that overlook the capacity and the practical importance of actively engaging these societies in wildlife management. In Zambia participation by local village communities in this management is recognized as a prerequisite for wildlife development and conservation. This participation is permitted through the administrative management design (called ADMADE) for game management areas. To help improve the capacity of rural communities to become more knowledgeable and effective in managing their wildlife resources, a geographical information system (GIS), based on ARC/INFO software, was applied and tested as an appropriate technology. It was hypothesized that maps composed of easily recognizable information about land use issues affecting the welfare of local residents and their natural resources would facilitate communal societies to make technically improved land use decisions with broad‐based support within the community. Results offered a growing set of achievements in land use planning by local community leaders in support of this hypothesis. Custom designed maps produced by this technology were used by these leaders to explain and build consensus at the community level on ways to resolve resource use conflicts. Results also demonstrated the pragmatic and cost‐effective value of training local residents to participate in the collection of GIS data as a way of making maps more locally acceptable and better focused on relevant issues and needs.

ISSN:1051-0761    

DOI:10.2307/2269337

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY

摘要:

Wildlife management in tropical areas inhabited by rural people requires an understanding of the interactions between game choice of hunters and the biology of game species. This paper presents an analysis that combines information on game use and game biology in an attempt to understand better the game hunting system and its effect on mammalian populations. Game choice by non—tribal inhabitants was studied in the north—eastern Peruvian Amazon within the Reserva Communal Tamshiyacu—Tahuayo (RCTT). The correlation between game preferences and actual harvests was calculated using Ivlev's index of selectivity. Hunters preferred large—bodied mammals and mammals with high economic value. Actual harvests did not reflect preferences of hunters, but were correlated with reproductive productivity of game species, measured as the species rmax. Impact of hunting on the biomass of game was not correlated with preferences of hunters or actual harvests. Both game choice by hunters and susceptibility of species to hunting depended mainly on the reproductive productivities of game species. Thus, game management in the RCTT must consider the dominating effects of reproductive biology and consider variance in rmaxwhen determining harvests.

ISSN:1051-0761    

DOI:10.2307/2269338

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY

摘要:

In the Atlantic lowland tropical rainforests of the Rio San Juan region, Nicaragua, we are conducting applied vegetation community analyses within an attempt to integrate non—timber forest products with natural forest management. Two long—term sampling plots were evaluated: one primary tropical rainforest plot before and 1 yr after selective logging, and another plot 9 yr after selective logging with and without Hutchinson Liberation Silviculture treatment (in which selected young trees are released from competition for light). The purpose of the study was to evaluate changes in community ecology variables with logging, damage, regeneration, and silviculture, both for useful plant species and for the plant community as a whole, and to evaluate the potential for incorporating non—timber forest product management with silvicultural management. One year after logging there was an increase in species (from 19± 5 to 33± 10 species/10m2) and density (from 42 ± 19 to 120 ± 60 plants/10m2) due to establishment or increase of secondary species (vines, grasses, balsa, cecropia) and to seedling regeneration after logging. The more severe the logging damage the more severe were the effects on some variables, particularly increased densities of vines and secondary species. Forest plots 9 yr post—harvest appeared to be returning to pre—harvest levels of species (28 ± 6 species/10m2) and density (76 ± 21 plants/10m2). Hutchinson Liberation Silviculture, while promoting growth of desired timber, did not significantly affect either non—timber forest products or the basic physiognomy of the forest. These results are contrasted with other silvicultural systems, particularly the Hartshorn Strip Clearcut, in which regeneration was dominated by resprouts and the proportion of vines was even higher. Hutchinson Liberation Silviculture provides the potential for simultaneous management of non—timber forest products, and moreover, non—timber forest product management holds the potential for significantly reinforcing silvicultural management.

ISSN:1051-0761    

DOI:10.2307/2269339

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY

摘要:

There are few if any examples of the demonstrably sustainable extraction of either timber or non—timber forest products. Even well—known products such as brazil nuts and mahogany lack a sufficient knowledge base to design a sustainable extraction system. Potential extraction systems for timber and non—timber forest products from tropical forests should be evaluated both in terms of their sustainability and their impact at the ecosystem level. The impact of forest product harvest on the demographics of the target species can be explored with the use of mathematical models, although we still lack an adequate understanding of some of the basic processes that are structuring tropical tree communities. Matrix models are relatively quick to construct, and they may be appropriate for modeling the dynamics of populations that are harvested without introducing large changes to the ecosystem, while individual—based mechanistic models are more appropriate for modeling the effects of harvest that cause large changes in population and ecosystem structure. Once the maximum sustainable level of harvest has been identified with the use of models, an economic analysis of the range of harvest intensities between zero and maximum sustainable yield should be conducted, with the goal of identifying the range of possible harvest intensities that are both sustainable and economically viable. This range of harvest intensities should then be analyzed in terms of its impact on the ecosystem, so that the harvest intensity that is chosen will not result in impacts to the forest that are unacceptably high.

ISSN:1051-0761    

DOI:10.2307/2269340

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY

摘要:

Five years of research have increased our understanding of the effects of disturbances on some forest processes and given directions for forest management in Guyana. At present most logging concentrates on Chlorocardium rodiei (greenheart) and current practices are damaging, but they may have little effect on the overall water balance and nutrient cycle if some simple rules are adhered to. The basic research results do not lead to a fully documented sustainable forest management system, as translation to practical management is not always simple. In general it would appear that applied research may give fast results in an often quick and dirty approach. Basic research, if directed at the right forest processes, may provide answers when the quick and dirty approach does not fulfil its objectives. As such they are complementary. In tropical forest management we cannot wait until basic research provides all answers leading to proper forest management, and a combination of the two would probably provide most answers in the long term.

ISSN:1051-0761    

DOI:10.2307/2269341

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY

ISSN:1051-0761    

DOI:10.2307/2269342

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY

摘要:

With the exception of the tropics, nowhere has the relationship between resource management and conservation of biological diversity been more controversial than in the Pacific Northwest region of the United States. Widespread loss and fragmentation of old—growth ecosystems have stimulated critical review and revision of existing forest management policies. However, studies of the consequences of forest management for plant species diversity are sorely lacking. We present data from permanent—plot and chronosequence studies in managed and unmanaged forests of western Oregon and Washington to describe the early responses of understory communities to forest harvest, and to suggest how post—harvest practices that alter natural successional processes may influence long term patterns of diversity and species occurrence. Permanent—plot studies of early succession in old—growth Pseudotsuga forests suggest that changes in understory diversity are fairly short—lived following clear—cut logging and slash burning. Populations of most vascular plant species recover to original levels prior to canopy closure. However, diversity may remain depressed for more than two decades on severely burned sites, and some species may experience local extinction. Evidence of the effects of post—harvest practices on vascular plant diversity is limited by an absence of community—level studies in older, managed forests. Chronosequence studies of natural forest stands indicate that, following canopy closure, vascular plant species diversity tends to increase with time, peaking in old growth. Few understory species are restricted to, or absent from, any stage of stand development (i.e., young, mature, or old growth). However, many species differ significantly in their abundance among stages. A majority of these showed greatest abundance in old growth. Changes in levels of resources (increased shade), changes in the spatial variability of resources and environments (increased horizontal and vertical heterogeneity), and species' sensitivity to fire and slow rates of reestablishment/growth may drive these trends during natural stand development. Silvicultural prescriptions that maintain or foster spatial and temporal diversity of resources and environments will be most effective in maintaining plant species diversity. Practices associated with intensive, short—rotation plantation forestry, that preclude or delay the development of old—growth attributes, may result in long—term loss of diversity. Ultimately, it may be necessary to manage some stands on long rotations (150—300 yr) to maintain understory species that require long periods to recover from disturbance.

ISSN:1051-0761    

DOI:10.2307/2269343

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY

摘要:

The ecological literature on eastern forest‐floor herbs and data collected in the southern Appalachians in Tennessee and North Carolina suggest five possible ecological mechanisms for reducing or limiting alpha diversity of vernal herbs in logged stands, three of which may also account for the slow recovery of some herbaceous species: (1) logging reduces populations of rarer herbs; (2) populations of forest‐floor species are further reduced during the successional stages following logging, either by inability to adapt to changed microclimate or by competition withr‐selected species that are better dispersers and better able to tolerate desiccation and increased radiation; (3) forest‐floor herbs have slow growth and reproduction rates, thus population densities increase slowly; (4) many forest‐floor herbs are clonal, ant‐dispersed, or gravity‐dispersed, thus they are slow to reoccupy suitable habitat once extirpated or greatly reduced in population numbers; and (5) logging results in less‐than‐optimal conditions for forest‐floor herb reproduction by modifying microhabitats on the forest floor and by temporarily eliminating gap‐phase succession. The data indicate some species of vernal herbs are far more tolerant of disturbance than others, and that sensitive species can be identified and utilized as indicators of community integrity and diversity.

ISSN:1051-0761    

DOI:10.2307/2269344

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY

摘要:

The current interest among resource managers in ecosystem management necessitates a better understanding of the response of plant species diversity to forest management practices. This study attempted to assess the effects of one forest management practice–clear‐cutting–on plant biodiversity in a mid‐Appalachian hardwood forest by comparing species composition and diversity between two young (≈ 20 yr following clear‐cutting) and two mature (>70 yr following selective cutting) watersheds. Sampling was confined to the herbaceous layer (vascular plants ≤ 1‐m in height) and woody overstory (stems ≥ 2.5 cm diameter at 1.5‐m height). The important tree species occurred on all watersheds, but the relative importance of these species varied greatly with stand age. Less shade‐tolerant species, such as black cherry (Prunus serotina) and tulip poplar (Liriodendron tulipifera), are replaced by more‐tolerant species, such as northern red oak (Quercus rubra) and sugar maple (Acer saccharum), as the stand matures. Analysis of tree species richness per plot suggests that the competitive thinning process decreases species evenness as the stand develops. Important herb‐layer species included stinging nettle (Laportea canadensis), violets (Viola spp.), seedling of striped maple (A. pensylvanicum), and several fern species. In sharp contrast with the trees, these species appeared to vary little with stand age. Species diversity (H') did not vary with stand age for either the overstory or the herbaceous layer. Detrended correspondence analysis showed a significant correlation between species composition of the two strata for the mature watersheds, but not the young, clear‐cut watersheds. Thus, we suggest a temporal shift in processes influencing species composition following disturbance from allogenic factors (e.g., soil characteristics) to autogenic factors (e.g., stand characteristics), which lead to a linkage between forest strata later in succession. The degree to which forest management alters species composition in these central Appalachian forest ecosystems may be tied to the degree of alteration of the link between strata.

ISSN:1051-0761    

DOI:10.2307/2269345

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY

摘要:

Increasing demands for products and services from tropical forests require solutions that conserve biodiversity while responding to human needs. I review various paradigms of tropical forest resiliency and fragility to focus attention on the management of biodiversity. The management of tropical biodiversity is possible within the context of land use programs that focus on ecosystem management. New ecological paradigms of tropical‐forest resiliency underpin tropical‐ecosystem management. They can and/or should replace paradigms that highlighted ecosystem fragility and led to the belief that tropical forests cannot be managed. To lead the way in tropical‐ecosystem management, ecologists must also consider social, political, and economic factors that affect the way people relate to the biota. Ecosystem management will require use of modern technology to mitigate the negative consequences of poor development and land use practices. In spite of efforts to preserve ecosystems as they occur today, species composition of future tropical forest landscapes will be different than today's.

ISSN:1051-0761    

DOI:10.2307/2269346

出版商:Ecological Society of America    

年代:1995

数据来源: WILEY