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2000—2021年广西森林资源数量与质量动态分析 被引量:1
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作者 庞正轰 于永辉 +4 位作者 莫烔松 阳晶晶 韦应强 唐天 石驭天 《桉树科技》 2023年第4期63-72,共10页
2000—2021年,广西森林资源数量发生了巨大变化。森林面积从981.91万hm~2增加到1486.37万hm~2,森林蓄积从37076万m^(3)增加到97822万m^(3),森林覆盖率从41.32%上升到62.55%,林地利用率从71.84%上升到92.11%,年均单位面积生长量从4.09 m^... 2000—2021年,广西森林资源数量发生了巨大变化。森林面积从981.91万hm~2增加到1486.37万hm~2,森林蓄积从37076万m^(3)增加到97822万m^(3),森林覆盖率从41.32%上升到62.55%,林地利用率从71.84%上升到92.11%,年均单位面积生长量从4.09 m^(3)·hm^(-2)上升到7.97 m^(3)·hm^(-2),平均单位面积蓄积量从48.80 m^(3)·hm^(-2)上升到84.25 m^(3)·hm^(-2)。森林年生长量从4018.17万m^(3)增加到9137.0万m^(3),年度木材产量从1637.06万m^(3)增加到3899.58万m^(3)。根据2000—2021年历次广西森林资源连续清查及监测结果,采用层次分析法从森林起源、森林结构、森林产能、森林健康、森林价值5个方面37项指标对森林资源进行了质量评价,结果表明2000—2021年森林质量从及格等级上升到良好等级。对森林质量提升原因进行了系统分析,认为政策驱动、市场引领、加大投入、科技支撑、科学管理是提升森林质量的重要因素。为提升广西森林资源质量和实现高质量发展,提出了调整林种结构、树种结构、龄组结构、加强幼林抚育管理、适当调减森林采伐量等对策措施。 展开更多
关键词 森林资源数量 森林质量 动态分析
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塔里木盆地西南缘森林与林地数量红线的遥感方法研究
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作者 全小丽 《区域治理》 2020年第38期102-104,共3页
森林数量红线是国家保护森林与林地的一种手段,是管理森林与林地的工具,也是对森林和林地评价的尺度和标准。森林与林地数量红线的制定已经到了关键时期,条件已经成熟,利用遥感影像成果,从人口、水资源等方面综合进行科学地统计分析,计... 森林数量红线是国家保护森林与林地的一种手段,是管理森林与林地的工具,也是对森林和林地评价的尺度和标准。森林与林地数量红线的制定已经到了关键时期,条件已经成熟,利用遥感影像成果,从人口、水资源等方面综合进行科学地统计分析,计算出森林与林地数量红线,为地区的生态环境保护建设、产业结构布局及社会经济的发展提供科学的依据和建议。 展开更多
关键词 塔里木盆地 森林数量红线 林地数量红线
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以森林资源增长为突破口推进林业供给侧改革 被引量:1
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作者 储艳苗 《现代农业科技》 2017年第2期120-121,共2页
基于生态论观点来看,供给侧改革三要素可以表述为人、资源和科学技术,重点是社会管理方式的改革,通过科学、公平的公共管理政策,合理配置资源,激活人的活力,以及实行科学、持续、高效的资源利用方式,从而实现社会的公平有序与发展。就... 基于生态论观点来看,供给侧改革三要素可以表述为人、资源和科学技术,重点是社会管理方式的改革,通过科学、公平的公共管理政策,合理配置资源,激活人的活力,以及实行科学、持续、高效的资源利用方式,从而实现社会的公平有序与发展。就林业供给侧改革而言,重点在于加大森林资源培育力度,培育健康森林,促进森林数量与质量双增长。 展开更多
关键词 林业 供给侧 改革 森林质量 森林数量
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Using multispectral landsat and sentinel-2 satellite data to investigate vegetation change at Mount St. Helens since the great volcanic eruption in 1980 被引量:2
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作者 Katharina TELTSCHER Fabian Ewald FASSNACHT 《Journal of Mountain Science》 SCIE CSCD 2018年第9期1851-1867,共17页
Long-term analyses of vegetation succession after catastrophic events are of high interest for an improved understanding of succession dynamics. However, in many studies such analyses were restricted to plot-based mea... Long-term analyses of vegetation succession after catastrophic events are of high interest for an improved understanding of succession dynamics. However, in many studies such analyses were restricted to plot-based measurements. Contrarily, spatially continuous observations of succession dynamics over extended areas and timeperiods are sparse. Here, we applied a change vector analysis(CVA) to investigate vegetation succession dynamics at Mount St. Helens after the great volcanic eruption in 1980 using Landsat. We additionally applied a supervised random forest classification using Sentinel-2 data to map the currently prevailing vegetation types. Change vector analysis was performed with the normalized difference vegetation index(NDVI) and the urban index(UI) for three subsequent decades after the eruption as well as for the whole observation time between 1984 and 2016. The influence of topography on the current vegetation distribution was examined by comparing altitude, slope angles and aspect values of vegetation classes derived by the random forest classification. WilcoxRank-Sum test was applied to test for significant differences between topographic properties of the vegetation classes inside and outside of the areas affected by the eruption. For the full time period, a total area of 516 km2 was identified as re-vegetated, whereas the area and magnitude of re-growing vegetation decreased during the three decades and migrated closer to the volcanic crater. Vegetation losses were mainly observed in regions unaffected by the eruption and related mostly to timber harvesting. The vegetation type classification reached a high overall accuracy of approximately 90%. 36 years after the eruption, coniferous and deciduous trees have established at formerly devastated areas dominating with a proportion of 66%, whereas shrubs are more abundant in riparian zones. Sparse vegetation dominates at regions very close to the crater. Elevation was found to have a great influence on the reestablishment and distribution of the vegetation classes within the devastated areas showing in almost all cases significant differences in altitude distribution. Slope was less important for the different classes-only representing significantly higher values for meadows, whereas aspect seems to have no notable influence on the reestablishment of vegetation at Mount St. Helens. We conclude that major vegetation succession dynamics after catastrophic events can be assessed and characterized over large areas from freely available remote sensing data and hence contribute to an improved understanding of succession dynamics. 展开更多
关键词 Mount St. Helens Vegetation change Remote sensing Change vector analysis (CVA) Supervised classification Topography Density-plots
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Soil Disturbance from Different Mechanised Harvesting in Hill Tropical Forest, Peninsular Malaysia
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作者 Mohd Hasmadi Ismail Norizah Kamarudin 《Journal of Environmental Science and Engineering》 2010年第1期34-41,共8页
The impacts of mechanised forest harvesting to soil physical properties are the major concern by forest managers, which have the potential to impact soil sustainability and forest productivity. Malaysia is practicing ... The impacts of mechanised forest harvesting to soil physical properties are the major concern by forest managers, which have the potential to impact soil sustainability and forest productivity. Malaysia is practicing reduce impact logging (RIL) and applying code of forest harvest practice in forest harvesting and operations for sustainable forest resources management. In 2001, a machinery called Rimbaka Timber Harvester R2020-A was introduced for timber extraction for peat swamp forest and later on the machine was introduced to the hill tropical forest as an alternative to other machines. The study aimed to evaluate soil compaction (soil cone index, soil bulk density, soil moisture content and soil pore space) by Rimbaka Timber Harvester R2020-A and crawler tractor KOMATSU D60-A. A total of five samples were randomly taken using core sampler of 50 mm height and 50 mm diameter at the beneath a lug imprint for passes 1, 4 and 8. Altogether samples were 45. The locations of sample were to the fight and left of each rut centre for both machines. Treatment effects were evaluated using analysis of variance (ANOVA). Result showed that compaction by Rimbaka machine was increased bulk density from 1.14 to 1.43 g/cc, cone index from 1.94 to 3.45 g/cm3 decreased total pore space by 43% and decreased soil moisture content by 19%. Meanwhile compaction by KOMATSU D60-A was increased bulk density from 1.2 to 1.43 g/co, cone index from 1.24 to 1.94 g/cm3 decreased soil moisture content by 11% and total pore space by 6%, respectively. The value increased rapidly as more passes increase on the track surface. The higher soil disturbance by Rimbaka machine was due to physical design and specification of the machine. This study also observed that there was significant difference in the total passes of machinery used in harvesting operation. Although Rimbaka machine is showing more effected to soil compaction, the machine is a practical alternative to avoid skid trail and reduce road density in forest area. 展开更多
关键词 Soil disturbance bulk density cone index pore space harvesting operation Rimbaka harvester system crawler tractor.
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Assessment and analysis of microwave emissivity and transmissivity of a deciduous forest towards the estimate of vegetation biomass 被引量:2
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作者 ZHANG ZhongJun YU XianChuan +1 位作者 ZHAO ShaoJie CHAI LinNa 《Science China Earth Sciences》 SCIE EI CAS 2014年第3期534-541,共8页
Forests play an important role in the global carbon cycle and have a potential impact on global climatic change.Monitoring forest biomass is of considerable importance in understanding the hydrological cycle.Because o... Forests play an important role in the global carbon cycle and have a potential impact on global climatic change.Monitoring forest biomass is of considerable importance in understanding the hydrological cycle.Because of the problem of dense forest cover,no reliable method with which to retrieve soil moisture in forest areas from the microwave emission signature has been established.All of these issues relate to the microwave emissivity and transmissivity characteristics of a forest.The microwave emission contribution received by a sensor above a forest canopy comes from both the soil surface and the vegetation layer.To analyze the relationship of forest biomass and forest emission and transmissivity,a high-order emission model,the matrix-doubling model,which consists of both soil and vegetation models,was developed and then validated for a young deciduous forest stand in a field experiment.To simulate the emissivity and transmissivity of a deciduous forest in the L and X bands using the matrix-doubling model,the parameters of components of deciduous trees when the leaf area index varies from 1 to10 were generated by an L-system and a forest growth model.The emissivity and transmissivity of a forest and the relationships of these parameters to forest biomass are presented and analyzed in this paper.Emissivity in the L band when the leaf area index is less than 6 and at viewing angles less than 40°,and transmissivity in the L band are the most sensitive parameters in deciduous forest biomass estimation. 展开更多
关键词 forest biomass matrix-doubling microwave emission TRANSMISSIVITY L-SYSTEM
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