The Role of Roadsides in Plant Invasions: a Demographic Approach

Abstract:  Non-native plant species are common along roadsides, but presence does not necessarily indicate spread along the road axis. Roadsides may serve merely as habitat for a species spreading independently of roads. The potential conduit function of roads depends on the habitat specificity of the spreading species, its dispersal range relative to the spacing of roads in the landscape, and the relative importance of long- and short-range dispersal. We describe a demographic model of the road × species interaction and suggest methods of assessing conduit function in the field based on the model results. A species limited to roadside habitat will be constrained to spread along the road axis unless its long-range dispersal is sufficient to carry it across the intervening unfavorable area to another road. It will propagate along a road corridor at a rate determined by the scale of short-range dispersal. Effective management of an invasion requires distinguishing between the habitat and conduit functions, a distinction difficult to make with only snapshot data. Invasions can be reconstructed by several methods, but none is totally satisfactory. We suggest comparing stem distributions on transects parallel and perpendicular to the road axis, and beside the road, and away from it, with an idealized Gaussian curve. Such comparisons would allow discrimination between pattern determined by habitat suitability and pattern reflecting random and facilitated dispersal.     

Rural and Suburban Sprawl in the U.S. Midwest from 1940 to 2000 and Its Relation to Forest Fragmentation

Abstract:  Housing growth and its environmental effects pose major conservation challenges. We sought to (1) quantify spatial and temporal patterns of housing growth across the U.S. Midwest from 1940–2000, (2) identify ecoregions strongly affected by housing growth, (3) assess the extent to which forests occur near housing, and (4) relate housing to forest fragmentation. We used data from the 2000 U.S. Census to derive fine-scale backcasts of decadal housing density. Housing data were integrated with a 30-m resolution U.S. Geological Survey land cover classification. The number of housing units in the Midwest grew by 146% between 1940 and 2000. Spatially, housing growth was particularly strong at the fringe of metropolitan areas (suburban sprawl) and in nonmetropolitan areas (rural sprawl) that are rich in natural amenities such as lakes and forests. The medium-density housing (4–32 housing units/km²) category increased most in area. Temporally, suburban housing growth was especially high in the post-World War II decades. Rural sprawl was highest in the 1970s and 1990s. The majority of midwestern forests either contained or were near housing. Only 14.8% of the region's forests were in partial block groups with no housing. Housing density was negatively correlated with the amount of interior forest. The widespread and pervasive nature of sprawl shown by our data is cause for conservation concern. Suburban sprawl has major environmental impacts on comparatively small areas because of the high number of housing units involved. In contrast, rural sprawl affects larger areas but with less intensity because associated housing densities are lower. The environmental effects per house, however, are likely higher in the case of rural sprawl because it occurs in less-altered areas. Conservation efforts will need to address both types of sprawl to be successful.     

四川土法炼磺区土壤环境化学变化初探

土法炼磺特大的“三度”排放量以及对生态环境所造成的难以逆转的毁坏,已引起社会各界的关注,但是炼磺危害区土壤环境的化学变化,却尚未曾有过专门研究。本文根据土壤样品的测定结果,探讨了四川土法炼磺区土壤环境的化学变化。结果表明:土壤PH值约降低1.1—2.4,重金属元素Cu、Zn、Cd、Pb、Ni、Mn、Fe的富集率约为30—150％,以有效态含量为标志的元素活性约增加20—55％。     

Indigenous Grass Ecology and Socio-Economic Values in Swaziland

The fast-degrading land resources of Swaziland requires a multi-faceted approach to their management. One resource of utmost importance to all Swazis is grass. Grass research over the years had focused on pasture grass, while other uses have been neglected. The omission is a serious one and could be attributed to the neglect of indigenous grass knowledge and people's socio-economic values of grasses. Grass as a major resource is used for cattle feed, ecological control measures, medicinal plants and crafts. Within the study area, 46 grass species were identified and described by the local people. The neglect of the people's knowledge and utilitarian values of grass is a waste of resources. Thus, for grass research to be relevant to the people and national development objectives, research scientists should rethink their approach; they need to recognize and incorporate the indigenous knowledge about other uses of grasses.     

Mortality rate and population density regulation in the great tit, Parus major L.: A review

A comparative analysis of published estimates of survival rates in different populations of great tits is made separately for adult and juvenile birds. The relationship between environmental conditions and demographic parameters in the reproduction of populations is discussed. Published in Russian in Ekologiya, 2006, No. 3, pp. 199–207. The article was translated by the author.     

Trends in Sex Ratios of Turtles in the United States: Implications of Road Mortality

Abstract:  Road mortality has been implicated as a significant demographic force in turtles, particularly for females, which are killed disproportionately on overland nesting movements. Moreover, the United States' road network has expanded dramatically over the last century. We therefore predicted that historical trends in sex ratios of turtle populations would be male biased. To test this prediction, we synthesized published estimates of population-level sex ratios in freshwater and terrestrial turtles in the United States (165 estimates for 36 species, published 1928–2003). Our analysis suggests that the proportion of males in populations has increased linearly ( p = 0.001); the trend in male bias is synchronized with the expansion of the surfaced portion of the road network since 1930; sex ratios became more male biased in states with higher densities of roads; and populations have become more male biased in aquatic species, in which movement differentials between males and females are greatest, and are least biased in semiaquatic and terrestrial species, in which overland movements are more comparable between sexes. Our results suggest an ongoing depletion of breeding females from wild turtle populations over the last century because of many factors, including, and perhaps chiefly, road mortality.     

Cultural values of natural resources among the San people neighbouring Kgalagadi Transfrontier Park,South Africa

Globally, cultural values of natural resources are increasingly recognised as important for local natural resource management and conservation in and beyond parks. The tendency has been to focus on the direct-use rather than the cultural values and importance of natural resources. The cultural values underlying natural resources (directly or indirectly used) and various natural resource-based activities, and the implications for conservation, remain little explored. Drawing from household surveys, in-depth qualitative interviews, observations and secondary data, we explore the cultural significance of natural resources and different land-use practices among the San people bordering Kgalagadi Transfrontier Park in South Africa. Our findings illustrate that though cultural values are inextricably linked to resource use, they are not recognised by all community members. Further, cultural values arise from a diverse and sometimes conflicting array of values that punctuate individuals' lifestyles. A better understanding of context-specific cultural settings and the linkages between the cultural and material dimensions of resource use can lead to the development of interventions that can ensure effective conservation of both natural resources and culture.     

Cultural issues in post‐disaster reconstruction: the case of Typhoon Morakot in Taiwan

Most members of Taiwan's indigenous communities live in areas that are prone to natural disasters. Yet, due to their marginalised cultural, economic and political status, each time such calamities strike, any assistance they receive is usually provided without considering their actual needs. The areas hardest hit by Typhoon Morakot in August 2009 were the indigenous villages in the southern and eastern parts of the island. After the initial emergency relief efforts had been completed, there remained the highly challenging task of reconstruction and the resettlement of those who lost their homes and livelihoods. This paper examines the cultural conflicts that arose during the reconstruction process, with special emphasis on the participation of Taiwan's indigenous communities and their capacity for resilience. It was found that community participation and identification are key issues in effective disaster governance.     

Towards sustainable community‐based natural resource management in the indigenous Meqmegi community in Taiwan: Rethinking impacts of local participation

This paper examines approaches for local resident participation in community‐based natural resource management (CBNRM); focusing particularly on the potential impacts that local participation imposes on the natural environment. This study used qualitative methods to collect data, and selected Meqmegi, an indigenous community in Taiwan, as a case study. The findings indicate that many opportunities can be created that stimulate a community to participate in natural resource management; moreover, residents are prone to use their own ways to participate. Therefore, although local participation is praised for its people‐oriented way of natural resource management, impacts from the participation process will ultimately be imposed on the environment. We suggest that more consideration be given to the environmental conditions during the process of local participation via CBNRM to make sure that impacts on the environment are positive, and lead to a truly sustainable future.     

Kibale Forest Wild Coffee: Challenges to Market‐Based Conservation in Africa

Abstract: Declining rural security and pressures to reduce public‐sector expenditures in the late 1990s spurred efforts to develop alternative funding models for Uganda's Kibale National Park (KNP). The Wild Coffee Project, established in 1999 with support from the U.S. Agency for International Development, the World Bank, and the Ford Foundation, sought to develop a market for wild coffee that had been harvested traditionally from areas within today's KNP. The Kibale Forest Foundation, a U.S.‐based nonprofit organization, was created to legalize harvests, obtain third‐party wild and organic certification, and coordinate management between KNP, the coffee industry, and local communities. Although the project was successful in legalizing, harvesting, and processing the world's first certified wild and organic coffee, efforts to gain entry into the international marketplace failed. Chief among the lessons learned from this project is that for many wild‐grown products, the value of “the story”—in both human and conservation terms—is likely to far exceed actual product values. This value differential should be captured through high‐value niche markets to avoid low commodity pricing and subsequent pressures to improve financial returns through over harvesting. In addition, local producers should hold significant assets in whatever brands are developed, creating a shared‐equity approach that serves social responsibility goals, fosters project sustainability, and ensures a steady stream of positive stories for use in marketing to build brand value. Shared equity—in this case ownership interest in the intellectual property embodied in the brand—provides a second incentive beyond transactional profits that can only be realized if resource conservation is maintained.