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511.
This study addresses the effect of political transition and subsequent timber bans on forest loss in Myanmar, in the context of identified drivers. Cook’s Distance (CD) was applied to remotely sensed time-series forest loss dataset to measure the effect of the events. Forest loss derived fragmentation metrics were linked to drivers at a landscape scale. Results show that at the national level, the political transition in 2011 had maximum effect (CD 0.935) on forest loss while the timber bans decreased forest loss by 612.04 km2 and 213.15 km2 in 2015 and 2017 (CD 0.146 and 0.035), respectively. The effect of the events varied for different States/Regions. The dominant drivers of change shifted from plantations in 2011 to infrastructure development in 2015. This study demonstrates the effects of policy on forest loss at various scales and can inform decision-makers for forest conservation, planning and development of mitigation measures.  相似文献   
512.
Key Elements of Landscape Pattern Measures   总被引:9,自引:0,他引:9  
  相似文献   
513.
This study examines and critiques “nature-deficit disorder” (NDD), Richard Louv's popular theory of how and why children are alienated from nature. Specifically, I explore NDD within the context of one forest conservation education program that aligns with and operationalizes Louv's message. Underlying Louv's and forest educators' discourses are culturally specific assumptions about human-nature relationships. Both evoke a fall-recovery narrative—that children are separated from nature and must return—and promote science and naming to reconnect. I argue that, in the absence of deeper cultural examination and alternative practices, NDD is a misdiagnosis—a problematic contemporary environmental discourse that can obscure and mistreat the problem. I call on adults to rethink human-nature disconnectedness by returning to the psyche, digging deeper to the problem's cultural roots, and using nontraditional communication practices such as emotional expression and non-naming.  相似文献   
514.
One year old needles of both healthy and damaged silver fir and Norway spruce from the area of Trento (Northern Italy) were observed by SEM. Needles of damaged trees show quite evident structural alterations of epidermis, expecially epicuticular waxes. Roots and needles of both fir and spruce are also tested for their metal content. Evidence is reported of an increasing concentration of Fe, Mg and Ca in roots of plants grown on alkali soil. Ca, and to a lesser extent Fe, Al and Pb, appears to be more present in old needles, whereas K and Mg exhibit higher amounts in young needles. Some indications are found between damage and the content of some metals such as Mg and Mn in needles.  相似文献   
515.
Sustainability has become a major focus area within forest products industry. The European operational environment and national environmental steering in EU member states highlight the importance of sustainable development and the development of associated new management approaches to promote sustainability. This article reviews some key elements of sustainability management, covering examples of both Finnish forest products industry initiatives and public environmental steering at the European level. An assessment is made of the current situation and an outline of a future outlook for sustainability management, with special emphasis on bridging the gap between industry initiatives and environmental steering in the form of legislation, policies and strategies at the EU level.This study applied a hybrid approach comprising a review of EU sustainability initiatives, a policy and legal review and a questionnaire survey of forest industry actors. The results of the future outlook indicate that energy efficiency is perceived to be the most important focus area in addition to e.g. environmental and waste management and recycling. Less than half of the companies aim at applying sustainability management. Life-cycle management is also considered to be important whereas product-based approaches, climate change and local industrial symbiosis receive very little attention. All responding companies aim to integrate the principles of sustainability into their operations and most companies consider that life-cycle thinking, management and assessment are useful for them. Energy efficiency is identified as the most important focus area with energy and materials efficiency seen as the most crucial factors for the achievement of responsible competitive advantage and building of sustainable value-added. The findings indicate that sustainability and life-cycle management are not receiving enough management focus at the moment and neither is the industry receiving enough guidance at either the EU level or via national steering and regulatory frameworks.  相似文献   
516.
The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5 yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C + H) loss of up to 38%, while loss for the other wood types was 0–10% in most samples. The C + H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27 g OC g?1 dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than previously reported.  相似文献   
517.
Abstract

The spatial distribution of hexazinone and two primary metabolites were measured in forest soil for two years following the aerial application of a granular formulation, PRONONE 10G, in northern Alberta. Residues were quantified using solid‐phase extraction and capillary gas chromatography. Initial deposition rates of two hexazinone treatments averaged 2.3 ± 0.5 and 4.1 ± 0.8 kg/ha for each triplicated plots. One year after application, residues of hexazinone averaged 0.25 ± 0.09 and 0.40 ± 0.02 kg/ha in 2.3 and 4.1 kg/ha treatment, respectively, in the 0–10 cm surface soil; and were distributed vertically in soil depths of 0–10, 10–20, and 20–30 cm at ratios of 10:11:2 and 10:5:2, respectively, in 2.3 and 4.1 kg/ha treatment. Metabolites A and B amounted to 15 and 30% of hexazinone, respectively. Two years after application, the vertical movement of hexazinone in soil was quantifiable to the 40‐cm depth in both 2.3‐ and 4.1‐kg/ha treatment plots. Trace amounts of hexazinone were detected at 130 cm only in the 2.3‐kg/ha plot, which is likely due to the more freely downward movement of hexazinone to deeper horizons along decayed root channels.  相似文献   
518.
Abstract

Four techniques were studied for capacity to preserve sixteen organophosphorous pesticides in distilled water and in creek water. A technique using chloroform effectively preserved all sixteen pesticides for the three weeks of the study and refrigeration was effective for fourteen of the pesticides, but buffers of pH A and pH 7 appeared undependable as preservatives.  相似文献   
519.
The influence of different concentrations of ozone under different light intensities on young trees of European beech (Fagus sylvatica L.) is studied. Young beeches were exposed continuously for 5 months in fumigation chambers, located outdoors, with 131±30/μg/m3O3, and for 2 months in fumigation chambers, located in air‐conditioned greenhoouses, with 100±10, 200±20 and 300±30/μg/m3O3, respectively. The observed symptoms point towards an increased xeromorphism in beech leaves, positively influenced by high light intensities. Ozone‐induced water stress may be the cause of xeromorphic tissue changes. On the ultrastructural level chloroplasts have become senescent.  相似文献   
520.
Twenty years after the Chernobyl accident, root uptake from the surface layers of contaminated forest soils plays a major role in radiocaesium ((137)Cs) transfer to the trees and accumulation in perennial compartments, including stemwood. Trustworthy long-term predictions (modelling) of stemwood contamination with (137)Cs should accordingly be based on a reliable picture of this source-sink relationship. Considering the complexity of the processes involved in (137)Cs cycling in forest stands, elementary ratios like transfer factors (TF) were shown to be not very relevant for that purpose. At the tree level, alternatives like the wood immobilisation potential (WIP) have therefore been proposed in order to quantify the current net (137)Cs accumulation in stemwood. Our objective was here to compare WIP values determined for a series of contaminated forest stands in Belarus with the corresponding pools of (137)Cs available in the soil for root uptake. The comparison reveals that both indices are quite proportional, whatever the forest ecosystem features. This corroborates the relevancy of WIP as an indicator of the current (137)Cs root uptake by the trees, which could accordingly help to improve the existing models of (137)Cs cycling and the long-term management of contaminated forest ecosystems.  相似文献   
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