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1.
In deciding to keep or fell a forest stand given its age, the risk of loss of timber through wildfire is an important consideration. If trees also have value from sequestration of carbon, another effect of fire is the unplanned loss of stored carbon. Factors affecting the decision to keep or fell trees, and how much to spend on fire protection, are investigated using stochastic dynamic programming, using carbon sequestration in stands of mountain ash in Victoria as a case study. The effect of treating sawlogs as a permanent carbon sink after harvesting is explored.  相似文献   

2.
The large-scale implementation of the Grain for Green project on the Chinese Loess Plateau since 1999 has greatly increased the vegetation coverage and rapidly decreased the agricultural land by converting slope cropland to planted vegetation (forest and grasslands). However, the geological, hydrological, ecological, and agricultural effects of the Gully Land Consolidation (GLC) project launched at Yan’an City in 2011 to address these land-use problems are not clearly understood. To assess the project outcomes in this region, we examined 71 of the 193 subprojects (61 treated gullies and 10 untreated gullies); measured geological, hydrological, ecological, and agricultural indices in the field; and tested disturbed (n = 447) and undisturbed (n = 142) soil samples (e.g., particle size distribution, saturated hydraulic conductivity, bulk density, and heavy metal contents). We found that: (1) slope stability improved for 67 % of the subprojects, (2) severe swamping was found only for 2 % of the subprojects, (3) the average increase in NDVI was 0.0231, 69 % of treated gullies NDVI was increased, and (4) crop yield was overall improved. There were no significant differences between the treated and untreated gullies in soil texture, saturated hydraulic conductivity, bulk density, or heavy metal contents (Cr, Zn, Cu, Ni, Pb), although particle size contents (range of 0.05 mm – 0.20 mm) differed significantly (p < 0.05). To promote successful gully land consolidation, the GLC project should (1) prioritize slope stability and long-term maintenance of water preservation facilities in gullies, (2) use bioengineering to accelerate the maturation of newly created land, or develop new cropping system after the GLC project; (3) on the basis of Grain for Green, integrate the GLC project, and modern agriculture to be complementary.  相似文献   

3.
Studies of land use policies are commonly based on the environmental impacts or on people's direct responses to the policies. However, research on the impact of policy implementation on people's livelihood and activities and the subsequent economic development of an area is incomplete. We selected Yanchang County as an example to track land use changes and their effects on the livelihood of the local population following the implementation of a new land use policy known as the Grain for Green Project (GGP). The data were collected from statistical yearbooks, questionnaire surveys, and satellite imagery from 1990, 2000, and 2008. We found that dramatic land use changes have occurred in Yanchang County. The vegetation coverage improved significantly from 1990 to 2008, as the grassland and forest areas increased from 44.1% to 60.1% and from 17.7% to 18.4% of the total land area, respectively. The cultivated land declined from 37.3% to 20.7%. With the agricultural area and grain production decreasing from 64 × 103 tons to slightly over 20 × 103 tons per year, an increasing number of local people sought employment in towns and cities. The non-farm income increased, and the local income structure shifted. Migrant and orchard worker income contributed the most to the balance of the total household income. We narrowed our focus to discuss how the GGP accelerated the changes in the participants’ lifestyles and what might be done to sustain the long-term effects of the GGP. While the GGP has brought about considerable environmental benefits, a comprehensive study of environmental–social systems is still needed to achieve a more efficient land use policy. The research results presented in this paper demonstrate that changes in land use and people's activities were triggered by policy changes. We aim to pave the way for studies on the “policy-land-use-social development” chain and to provide references for new policies.  相似文献   

4.
Road development in mountainous forestlands can lead to naturally formed slopes being disturbed. Efficient planning methodologies can assist forest engineers in either preventing or reducing the environmental impacts of forest roads. In this study, we first prepared an inclusive landslide susceptibility map for our study area using a Bayesian model. We next designed 12 road network alternatives using PEGGER, an ArcView GIS extension. We extracted the values of these alternatives from the susceptibility map to evaluate their environmental feasibility. We also evaluated the alternatives from an economic perspective using a model for conducting cost estimates of the forest roads. Our results show that this approach is useful for identifying the alternative that meets environmental and economic goals. The policy implications of this study suggest that if the development of road networks in mountainous areas is an important forestry goal, mechanisms should be aimed primarily at controlling slope instability.  相似文献   

5.
Selective logging (SL) contributes nearly 15 percent of the global timber needs. Considering its role in sustainable timber production, biodiversity conservation and forest carbon enhancement, assessment of SL policies and practices is crucial. This paper assesses the policies and practices of SL in natural production forests of the Tarai region of Nepal and Queensland Australia to explore the key differences in such policies and practices and their possible implications in achieving sustainable forest management objectives. The primary methods applied in the study were review and synthesis of key policy documents and qualitative analysis of the information gathered from key informant interviews and stakeholders’ workshop. Altogether, 53 respondents from a wide range of stakeholder groups (government organizations-15, non-government organizations/networks-15, private sector including the individual landowners-13, local political leaders-3 and independent forest experts/scientists-7) were consulted. Findings suggest that: (1) frequent and inconsistent changes in policy provisions, lengthy administrative procedures and heavy engagement of state forest agencies in forest product harvesting and sales processes play key roles in sub-optimal forest production in Nepal, whereas lower dependency on forest-products, higher labour costs, lack of species-wise royalty rate and flexibility in selecting optional logs are the key factors for increased wastages of forest products in Queensland; (2) recovery and utilisation of the harvested forest product is better in Nepal but policy and practical considerations on biodiversity and environment are better in Queensland; and (3) Forest harvesting specific codes of practice, occupational health and safety standards, and their compliance mechanism of Queensland could be beneficial for Nepal to minimise operational harvesting risks and to attract professional harvesters that support promoting sustainable use and management of natural forests, as we found this aspect almost neglected in Nepal.  相似文献   

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