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131.
M. Matucha M. Gryndler S. T. Forczek H. Uhlířová K. Fuksová P. Schröder 《Environmental Chemistry Letters》2003,1(2):127-130
The fate of chloroacetic acids (CAA) in forest soils was studied using radio-indicator methods. We showed that chloroacetic acids are both microbially degraded and simultaneously formed by chloroperoxidase-mediated chlorination of acetic and humic acids. The degree of biodegradation of chloroacetic acids in soil depends on their concentration. Dichloroacetic acid (DCA) is degraded faster than trichloroacetic acid (TCA). Chlorination of acetic acid led to a fast formation of dichloroacetic acid, whereas chlorination of humic acids gave rise to trichloroacetic acid. Both processes lead to a steady state in soil, participate in the chlorine cycle and possibly also in decomposition of organic matter in forest ecosystems. 相似文献
132.
133.
Yuepeng Zhou Xiaoping Shi Dengyan Ji Xianlei Ma Satish Chand 《Natural resources forum》2019,43(2):95-110
The decentralization of property rights is the focus of the forest tenure reforms in several developing countries. In China, it was achieved by the launch of a new round of collective forest tenure reform beginning in 2003, which provided farmers with more integrated and secure forestland rights. Drawing on household data collected in Jiangxi province in 2011 and 2013, this paper examines the impacts of households’ recognition of property rights and improved tenure security on forestland rental activities. Our empirical results show that households with higher perceptions of more complete use rights and mortgage rights have a lower probability and intensity of renting‐in land, while households with lower expectations of future forestland redistribution or expropriation are more likely to rent in forestland and more of it. These results imply that the development of a forestland rental market leading to better forest management requires an integrated forestland management approach consisting of decentralization of property rights and village governance. In particular, the central government may further clarify the rights and obligations affiliated to forestland ownership, contractual rights, and management rights; while the village collective may shift from direct intervention in the integrity and security of forestland rights to the supervision and protection of decentralized forestland rights to increase efficiency from the decentralization of property rights. 相似文献
134.
Ning Liu Jatin Kal Shirong Liu Vanessa Haver Bernard Dell Keith R.J. Smettem Richard J. Harper 《环境科学学报(英文版)》2020,32(4):262-274
Increasing atmospheric CO2 is both leading to climate change and providing a potential fertilisation effect on plant growth. However, southern Australia has also experienced a significant decline in rainfall over the last 30 years, resulting in increased vegetative water stress. To better understand the dynamics and responses of Australian forest ecosystems to drought and elevated CO2, the magnitude and trend in water use efficiency (WUE) of forests, and their response to drought and elevated CO2 from 1982 to 2014 were analysed, using the best available model estimates constrained by observed fluxes from simulations with fixed and time-varying CO2. The ratio of gross primary productivity (GPP) to evapotranspiration (ET) (WUEe) was used to identify the ecosystem scale WUE, while the ratio of GPP to transpiration (Tr) (WUEc) was used as a measure of canopy scale WUE. WUE increased significantly in northern Australia (p < 0.001) for woody savannas (WSA), whereas there was a slight decline in the WUE of evergreen broadleaf forests (EBF) in the southeast and southwest of Australia. The lag of WUEc to drought was consistent and relatively short and stable between biomes (≤3 months), but notably varied for WUEe, with a long time-lag (mean of 10 months). The dissimilar responses of WUEe and WUEc to climate change for different geographical areas result from the different proportion of Tr in ET. CO2 fertilization and a wetter climate enhanced WUE in northern Australia, whereas drought offset the CO2 fertilization effect in southern Australia. 相似文献
135.
This paper provides an overview of the emerging role of Aboriginal people in Sustainable Forest Management (SFM) in Canada over the past decade. The 1996 Royal Commission on Aboriginal Peoples (RCAP) provided guidance and recommendations for improving Aboriginal peoples' position in Canadian society, beginning with strengthening understanding and building relationships between Aboriginal and non-Aboriginal parties. This paper explores the extent to which advances in Aboriginal/non-Aboriginal relationships and Aboriginal forestry have been made as a result of RCAP's call for renewed relationships based on co-existence among nations. Such changes have begun to alter the context in which Aboriginal/non-Aboriginal relationships exist with respect to SFM. While governments themselves have generally not demonstrated the leadership called for by RCAP in taking up these challenges, industry and other partners are demonstrating some improvements. A degree of progress has been achieved in terms of lands and resources, particularly with co-management-type arrangements, but a fundamental re-structuring needed to reflect nation-to-nation relationships has not yet occurred. Other factors related to increasing Aboriginal participation in SFM, such as the recognition of Aboriginal and treaty rights, are also highlighted, along with suggestions for moving Aboriginal peoples' SFM agenda forward in the coming years. 相似文献
136.
Johan Uddling Alan J. Hogg Ronald M. Teclaw David S. Ellsworth 《Environmental pollution (Barking, Essex : 1987)》2010,158(6):2023-2031
Rising atmospheric carbon dioxide (CO2) may alleviate the toxicological impacts of concurrently rising tropospheric ozone (O3) during the present century if higher CO2 is accompanied by lower stomatal conductance (gs), as assumed by many models. We investigated how elevated concentrations of CO2 and O3, alone and in combination, affected the accumulated stomatal flux of O3 (AFst) by canopies and sun leaves in closed aspen and aspen-birch forests in the free-air CO2-O3 enrichment experiment near Rhinelander, Wisconsin. Stomatal conductance for O3 was derived from sap flux data and AFst was estimated either neglecting or accounting for the potential influence of non-stomatal leaf surface O3 deposition. Leaf-level AFst (AFstl) was not reduced by elevated CO2. Instead, there was a significant CO2 × O3 interaction on AFstl, as a consequence of lower values of gs in control plots and the combination treatment than in the two single-gas treatments. In addition, aspen leaves had higher AFstl than birch leaves, and estimates of AFstl were not very sensitive to non-stomatal leaf surface O3 deposition. Our results suggest that model projections of large CO2-induced reductions in gs alleviating the adverse effect of rising tropospheric O3 may not be reasonable for northern hardwood forests. 相似文献
137.
Abstract: Regional conservation planning increasingly draws on habitat suitability models to support decisions regarding land allocation and management. Nevertheless, statistical techniques commonly used for developing such models may give misleading results because they fail to account for 3 factors common in data sets of species distribution: spatial autocorrelation, the large number of sites where the species is absent (zero inflation), and uneven survey effort. We used spatial autoregressive models fit with Bayesian Markov Chain Monte Carlo techniques to assess the relationship between older coniferous forest and the abundance of Northern Spotted Owl nest and activity sites throughout the species' range. The spatial random-effect term incorporated in the autoregressive models successfully accounted for zero inflation and reduced the effect of survey bias on estimates of species–habitat associations. Our results support the hypothesis that the relationship between owl distribution and older forest varies with latitude. A quadratic relationship between owl abundance and older forest was evident in the southern portion of the range, and a pseudothreshold relationship was evident in the northern portion of the range. Our results suggest that proposed changes to the network of owl habitat reserves would reduce the proportion of the population protected by up to one-third, and that proposed guidelines for forest management within reserves underestimate the proportion of older forest associated with maximum owl abundance and inappropriately generalize threshold relationships among subregions. Bayesian spatial models can greatly enhance the utility of habitat analysis for conservation planning because they add the statistical flexibility necessary for analyzing regional survey data while retaining the interpretability of simpler models. 相似文献
138.
Minna Hares 《Environmental management》2009,43(3):381-395
This paper aims at exploring the local background of and solutions to the forest conflict in upland areas inhabited by ethnic
minorities, who are called hill tribes, in northern Thailand. A so-called hill tribe problem has been officially identified
as a result of the slash-and-burn cultivation and other perceived problems, such as opium poppy cultivation, illegal immigration,
and the suspicion of disloyalty to the state. This has created distrust and tension between the groups and authorities. The
local conflict has recently been related to the dilemma of conserving the forest from all human interference, while many people
live and make their livelihood within and adjacent to the protected areas. Furthermore, as the results imply, strictly protected
areas and reforestation have also increased the competition over land and natural resources and, thereby, the likelihood of
local conflicts. The scarcity and pollution of water, illegal logging, and poor fire control have contributed to the conflicts
between local communities. The conflicts between the local communities and officials have been nourished by political and
public discussions. Using definitions and terms with negative connotations and ignoring the heterogeneity between the groups
or labeling some groups as malevolent have increased distrust and strengthened existing stereotypical images. Conflict resolution
starts with efforts toward better mutual understanding, and changes in structures and attitudes are necessary. Local cooperation,
utilization of traditional methods, and local institutions are central to conflict solving. 相似文献
139.
Increasing recognition of the human dimensions of natural resource management issues, and of social and ecological sustainability and resilience as being inter-related, highlights the importance of applying social science to natural resource management decision-making. Moreover, a number of laws and regulations require natural resource management agencies to consider the “best available science” (BAS) when making decisions, including social science. Yet rarely do these laws and regulations define or identify standards for BAS, and those who have tried to fill the gap have done so from the standpoint of best available natural science. This paper proposes evaluative criteria for best available social science (BASS), explaining why a broader set of criteria than those used for natural science is needed. Although the natural and social sciences share many of the same evaluative criteria for BAS, they also exhibit some differences, especially where qualitative social science is concerned. Thus we argue that the evaluative criteria for BAS should expand to include those associated with diverse social science disciplines, particularly the qualitative social sciences. We provide one example from the USA of how a federal agency − the U.S. Forest Service − has attempted to incorporate BASS in responding to its BAS mandate associated with the national forest planning process, drawing on different types of scientific information and in light of these criteria. Greater attention to including BASS in natural resource management decision-making can contribute to better, more equitable, and more defensible management decisions and policies. 相似文献
140.
Forest carbon (C) sequestration is being actively considered by several states as a way to cost-effectively comply with the forthcoming United States (US) Environmental Protection Agency’s rule that will reduce power plant C emissions by 32% of 2005 levels by 2030. However, little is known about the socio-ecological and distributional effects of such a policy. Given that C is heterogeneous across the landscape, understanding how social, economic, and ecological changes affect forest C stocks and sequestration is key for developing forest management policies that offset C emissions. Using Florida US as a case study, we use US National Forest Inventory Analysis and Census Bureau data in both linear regression and quantile regression analyses to examine the socio-ecological and economic determinants of forest C stocks and its relationship with differing communities. Quantile regression findings demonstrate nonlinearity in the effects of key determinants, which highlight the limitations of regularly used mean-based regression analyses. We also found that forest basal area, site quality, stand size, and stand age are significant ecological predictors of carbon stocks, with a positive and increasing effect on upper quantiles where C stocks are greater. The effect of education was generally positive and mostly significant at upper quantiles, while the effects of income and locations with predominantly minority residents (as compared to whites) were negative. Upper quantiles were also affected by population age. Our findings underscore the importance of considering the broader socio-ecological and economic implications of compliance strategies that target the management of forests for carbon sequestration and other ecosystem services. 相似文献