Land cover mapping of deciduous forest regions using ETM+ data: a case study of Azerbaijan Province, Iran

Up to date information about the existing land cover patterns and changes in land cover over time is one of the prime prerequisites for the preparation of an integrated development plan and economic development program of a region. By using ETM＋ image data from 2002, we provided a land cover map of deciduous forest regions in Azerbaijan Province, Iran. Initial qualitative evaluation of the data showed no significant radiometric errors. Image classification was carried out using a maximum likelihood-based supervised classification method. In the end, we determined five major land cover classes, i.e., grass lands, deciduous broad-leaf forest, cultivated land, river and land without vegetation cover. Accuracy, estimated by the use of criteria such as overall accuracy from a confusion matrix of classification was 86% with a 0.88 Kappa coefficient. Such high accuracy results demonstrate that the combined use of spectral and textural characteristics increased the number of classes in the field classification, also with excellent accuracy. The availability and use of time series of remote sensing data permit the detection and quantification of land cover changes and improve our understanding of the past and present status of forest ecosystems.

Rational Harvesting Policy and Sustainable Development of Community in Forest Regions

Forest ecosystem is one of the most important ecosystems in the world that human-beings rely on. Forest harvesting policy is one of the main criteria indicating how and how much the human beings open up and make use offorest. Whether the policy is reasonable or not has high relations with not only the increasing or decreasing of forest system,but also the development speed of human society. In this paper, the author analyzed the development of interaction between human society and forest ecosystem from ancient times to today. Then author stated that the rational harvesting policy should be the harvesting sequences of both harvesting density and harvesting time, which might result in the maximumcomprehensive benefit, including economical profit, social benefit and ecological benefit, of forest to human society. Atlast, according to the analysis of interaction bctween human-beings and her environment, the prediction analysis for humansociety development in forest regions in the future was prescnted using Entropy Growing Analysis.

Anthropogenic Threats to Degraded Forest Land in the Savannahs’ Region of Togo from 1984 to 2020, West Africa

This study focuses on the landscape dynamics of the savannahs’ region in the far north of Togo. Based on a literature review and satellite images analysis using GIS and remote sensing, the study aims to ascertain the effects of anthropogenic threats on the forest coverage of the Savannahs’ Region between 1984 to 2020. The objective is to clarify the dynamics of land use in the region from 1984 to 2000 and from 2000 to 2020. The findings indicate a significant decline in forest coverage within the region from 1984 to 2020, a trend attributed to land use patterns. Dry forests in the Savannah region are largely converted to farmlands, housing, dry savannahs or agroforestry parks, leading to a steady reduction in forest areas.

Mapping and Floristic Diversity of the Nakpadjouak Community Forest, Tami Canton, Togo (West Africa)

Since 2015, community forests have been promoted in Togo as an alternative to protect areas from degradation and as a means of contributing to forest landscape restoration. The study focuses on the Nakpadjouak Community Forest (NCF) in Tami (Togo, West Africa) which contributes to community forests sustainable management. It aims in (i) mapping forest ecosystems and analysing their dynamic and (ii) characterizing the floristic diversity of the NCF. The ecosystems were mapped and their dynamic was evaluated based on Google Earth images of 2014 and 2020. Floristic and forestry inventories were carried out using the transect technique in a sample of 20 plots of 50 m × 20 m. The NCF was made up mainly by wooded/shrub savannahs (95.37%) and croplands/fallow (4.63%) in 2014. These two land use types undergone changes over the 6 years prior to 2020. By 2020, the NCF had 3 land use types: wooded/shrub savannahs (77.59%), open forest/wooded savannahs (22.23%), and croplands/fallows (0.18%). A total of 89 plant species belonging to 70 genera and 28 families were recorded within the NCF. The dominant species are: Heteropogon contortus (L.) P.Beauv. and Combretum collinum Fresen. followed by Pteleopsissuberosa Engl. & Diels, Annona senegalensis Pers. The most common species are: Lannea acida A.Rich. s.l., A. senegalensis, Vitellaria paradoxa C.F.Gaertner subsp. paradoxa, C. collinum and Acacia dudgeonii Craib ex Holland. Due to its small area of just 40 hectares and its diverse plant life, this community forest of Savannahs Region is a significant biodiversity hotspot and warrants conservation efforts.

Regional differences of water conservation in Beijing’s forest ecosystem

The water conservation capacities of main forests in Beijing,China were estimated through the quantitative analysis.Various methods developed in published papers on forest hydrology were employed.The forests in Huairou,Yanqing,Miyun,Mentougou and Fangshan districts are the main contributors to water conservation（the cumulative ratio reaches 65%）,and the forests in Tongzhou,Chaoyang,Shunyi and Daxing districts have the highest water conservation capacity（3000 m3/ha）.Altitude and slope are the key factors to affect the water conservation capacity.The forests located in Plain Area,Hilly Area,Low Mountain,and Middle Mountain contributes 27%,28%,24% and 21% of the conserved water,respectively.The water conservation capacity of forests in Plain Area（2 948 m3/ha）,is superior to the forests in other regions.And the forests situated on Flat Slope,Moderate Slope and Gentle Slope constitute the largest proportion（nearly 93%） of water conservation,while the forests on Flat Slope has the highest water conservation capacity（2 797 m3/ha）,and the forest on Steep slope has the lowest water conservation capacity（948 m3/ha）.

Causal effects of shelter forests and water factors on desertification control during 2000–2010 at the Horqin Sandy Land region, China

The Horqin Sandy Land（HSL）, the largest sandy land in the semi-arid agro-pastoral ecotone of Northeast China, has been subject to desertification during the past century. In response, and to control the desertification,government implemented the Three-North Shelter/Protective Forest Program, world＇s largest ecological reforestation/afforestation restoration program. The program began in1978 and will continue for 75 years until 2050. Understanding the dynamics of desertification and its driving forces is a precondition for controlling desertification.However, there is little evidence to directly link causal effects with desertification process（i.e., on the changing area of sandy land） because desertification is a complex process,that can be affected by vegetation（including vegetation cover and extent of shelter forests） and water factors such as precipitation, surface soil moisture, and evapotranspiration.The objectives of this study were to identify how influencing factors, especially shelter forests, affected desertification in HSL over a recent decade. We used Landsat TM imagery analysis and path analysis to identify the effects of spatiotemporal changes in water and vegetation parameters during2000–2010. Desertification was controlled during the study period, as indicated by a decrease in desert area at a rate of163.3 km2year-1and an increase in the area with reduced intensity or extent of desertification. Total vegetation cover in HSL increased by 10.6 % during the study period and this factor exerted the greatest direct and indirect effects on slowing desertification. The contribution of total vegetation cover to controlling desertification increased with the intensity of desertification. On slightly and extremely severe desertified areas, vegetation cover contributed 5 and 42 % of the desertification reduction, respectively. There were significant correlations between total vegetation cover and water conditions（i.e., evapotranspiration and precipitation）and the area of shelter forests（P ／ 0.0001）, in which water conditions and the existence of shelter forests contributed49.7 and 12.8 % to total vegetation cover, respectively. The area of shelter forests increased sharply due to program efforts, but only shrub forests had significant direct effects on reducing the area of desertification categorized as slightly desertified. The reason for the lack of direct effect of increased arbor forests（accounting for 95.3 % of the total increase in shelter forests） on reducing desertification might be that the selected arbor species were not suited to water conditions（low precipitation, high evapotranspiration） prevailing at HSL. The establishment of shelter forests aided control of desertification in the HSL region, but the effect was less than expected. Effective control of desertification in the HSL region or other similar sandy areas will require greater improvements in vegetation cover. In particular,shrub species should be selected for plantation with reference to their potential to survive and reproduce in the harsh climatic and weather conditions typical of desertified areas.

Assessing the vulnerability of a forest ecosystem to climate change and variability in the western Mediterranean sub-region of Turkey：future evaluation

This study evaluates the multifactorial spatial modelling used to assess vulnerability of the Du¨ zlerc？am？（Antalya） forest ecosystem to climate change.This was done to produce data,to develop tools to support decisionmaking and the management of vulnerable Mediterranean forest ecosystems affected by climate change,and to increase the ability of these forest ecosystems to adapt to global change.Based on regionally averaged future climate assessments and projected climate indicators,both the study site and the western Mediterranean sub-region of Turkey will probably become associated with a drier,hotter,more continental and more water-deficient climate.This analysis holds true for all future scenarios,with the exception of RCP4.5 for the period from 2015 to 2030.However,the present dry-sub humid climate dominating this sub-region and the study area shows a potential for change towards more dry climatology and for it to become semiarid between 2031 and 2050 according to the RCP8.5 high emission scenario.All the observed and estimated results and assessments summarized in this study show clearly that the densest forest ecosystem in the southern part of the study site,characterized by mainly Mediterranean coniferous and some mixed forest and maquis vegetation,will very likely be influenced by medium and high degrees of vulnerability to future environmental degradation,climate change and variability.

Predicting equations of main factors affecting regional climate in the"Three-North" Protective Forest Area

The relationship between the change of forest resources and climatic factor in the, “Three-North” region of China were studied in this paper. The predicting equations of climatic factor (dependent variable) with regional independent variable (longitude, latitude and altitude) and stand independent variable (forest coverage rate), were developed by extensively using the linear and nonlinear regression methods. With these models, we can calculate the ecological benefit of Shelter-belt forest.

Research on Converting Cultivated Land into Forests and Regional Sustainable Development

The capability of sustainable development of Wuchuan County is evaluated comprehensively with theories and methods of regional sustainable development capability evaluation, which are extensively applied at home and abroad. The results indicate that the developing speed and patterns of Wuchuan County cannot satisfy the demand of the regional sustainable development. Moreover, the patterns, distributions, tree species, growing patterns, and other aspects must consider the restriction of ecological water utilization. It is put forward that the standards for selecting the converting lands are slope, desertification degree, and rainfall.In addition, the control of soil erosion and the prevention of land desertification are selected as the dualpurpose of the converting project.

An Innovative Land Approach for Spatially Determining SDGs-Sustainably Governing German Spree Forest and Lusatia Region

In times of highest necessities for United Nations Sustainable Development Goals(SDGs)and acknowledging planetary boundaries,the need for understanding general global goals and regional to local strategic governing structures has to be supported while combining assessment,monitoring,governance approaches,together with landscape planning,land use based approaches,land system and sustainability science.The initial research embeds an incrementally worked out theoretical framework followed by applied research parts.The case studies and field data in the German Lusatia Region and inner part Spree Forest Region inhabit intrinsic drivers of finding ways over bridging deficiencies of theoretical and applied adjusted objectives and in this small excerpt mainly about the scale and planning level,instrumental flexibility deficiencies while transmitting global transformation needs to the regional,local planning level and backward(counter-current principle).Innovative instrumental assessment structures were created with a new approach of spatially determining SDGs for accelerated Climate Smart Planning(CSP)and Integrated Drought and Water Management(IDWM).This research supports processes around acceleration and assessment of climate change-,crises-related and sustainable development options while enhancing interdisciplinary sustainability science for gaining more regional land resilience.

Development Plan for Under- forest Economy of Henan Province Based on Central Plains Economic Region

Firstly,this paper analyzed current situations,major practice and existing problems of under-forest economy in Henan Province.Then,it made an in-depth discussion of guiding thought,principle and objectives,construction task and safeguarding measures of the underforest economic development plan. Besides,it analyzed benefits of the under-forest economic development plan. By 2017,the area of underforest economic land will reach 1. 60 million hm2,create output value of 155. 2 billion yuan( accounting for more than 20% of forest output value),provide 3. 27 million jobs,and will greatly increase ecological carrying capacity of construction and development of the Central Plains Economic Region( CPER).

Evaluation of the Land Production Potential in the Context of Returning Farmland to Forest in Karst Region:A Case Study of Guizhou Province

In this paper, we take Guizhou Province (the heart of southwestern Karst region in China) as the research object. By establishing gray forecasting model and time series forecasting model, we conduct the accuracy test on the actual production capacity of land and the forecasted production capacity of land in 2007 and 2008, and then conduct comprehensive forecast of the land production potential in Guizhou Province in 2020. On this basis, considering the nutritional standards needed by three kinds of life type (dressing warmly and eating one's fill, well-off life, relatively affluent life), we evaluate the land production potential in Guizhou Province under the project of returning farmland to forest. Based on the evaluation results, we put forth the relevant recommendations for achieving sustainable land use in the context of returning farmland to forest in Guizhou Province.

Eco-environment Restoration and Regional Differentiation Characteristics Based on “Building Terrace and Returning Slope Farmland to Forests and Grass”

Based on the scientific and technological achievements in the past decade in the Loess Hilly-gully Region and the successful demonstration experience in Yan'an Yangou watershed, we summarize the characteristics of eco-environment restoration pattern based on "building terrace and returning slope farmland to forests and grass". According to the data on land use, slope farmland and the agricultural population in 1999, we calculate the area of new terrace that needs to be built, the area of garden plot that needs to be extended, vegetation restoration area and investment demand in counties (cities, districts). Establishing and using some indicators, such as basic farmland extension indicator, garden plot extension indicator, vegetation restoration index and investment demand density, we conduct type classification and analysis of regional differentiation characteristics in 55 counties (cities, districts). The results show that in the Loess Hilly-gully Region, 691 600 hm2 of new terrace needs to be built, 792 000 hm2 of economic forests and orchards need to be extended, 5 410 200 hm2 of vegetation needs to be restored, and the total investment demand is 15.82 billion yuan; in terms of geographical distribution, obviously there are two key areas for eco-environment restoration (one is located in the border area between northern Shaanxi and northwestern Shanxi, and the other is located in the eastern Gansu and southern Ningxia area); the classified regional guidance policies should be formulated as soon as possible, and the limited funds should be concentrated in the key areas.

基于机器学习的“一带一路”投资国别风险预测研究

“一带一路”倡议提出十年间,中国对沿线国家的投资规模持续扩大。然而,企业在抓住机遇,进行“一带一路”沿线国家投资的同时,也需要重点关注“一带一路”投资国别风险。本文从政治、经济、社会和对华关系4个维度构建“一带一路”投资国别风险预测指标体系;运用灰色关联分析计算样本国家的综合风险评价值;基于2012~2022年间“一带一路”沿线国家的数据,利用机器学习构建GA-BP神经网络、支持向量回归和随机森林3种预测模型;通过对比预测精度,确定最佳预测模型,利用2021年的指标数据,对2022年的投资国别风险进行预测。研究结果表明:(1)在“一带一路”投资国别风险的研究背景下,支持向量回归模型预测效果最优,证明机器学习模型能够有效应用于风险管理领域;(2)“一带一路”投资国别风险存在明显的地区差异,中东欧地区和东南亚地区投资国别风险普遍较低,而南亚地区投资国别风险普遍较高,但都存在特例。本文研究结果可为“走出去”企业在“一带一路”沿线国家的投资决策提供参考。

关帝山3个典型森林群落优势种的氮素利用策略差异

【目的】研究关帝山林区华北落叶松林、白桦林和沙棘林3个典型森林群落优势种的新生枝叶氮含量、地上生物量和氮利用效率对5个土壤施氮梯度的差异化响应,阐明3个森林群落优势种不同的氮利用功能特性和氮利用策略,为氮沉降背景下的森林质量提升和精准经营提供理论依据。【方法】采用野外5梯度土壤氮(0、9、18、27和36 g·m^(−2) a^(−1))添加试验的方法,比较3个森林群落优势种和群落总体的新生枝叶氮含量、地上新增生物量和氮利用效率对土壤不同施氮量的响应;采用线性模型拟合地上新增生物量随新生枝叶氮含量、氮利用效率和土壤氮素供应水平的变化过程;通过构建结构方程模型,分析土壤氮添加影响地上新增生物量的作用路径。【结果】3个群落优势种的新生枝叶氮含量总体表现为华北落叶松<白桦<沙棘,新生叶氮含量显著高于新生枝,两者的差异表现为白桦>华北落叶松>沙棘,生长盛期的枝叶氮含量都高于末期,生长期之间的差异也表现为白桦>华北落叶松>沙棘;新生枝和新生叶在生长盛期和末期的氮含量都有随施氮量增加而增加的趋势,但3个优势种的变化表现出显著不同的趋势,饱和施氮量和饱和氮含量均表现为华北落叶松<白桦<沙棘;3个群落新生枝叶生物量都随施氮量的增大而升高,但递增率拟合结果表现为华北落叶松林>沙棘林>白桦林;群落氮利用效率都随施氮量增大而降低,以华北落叶松林的降幅最大,沙棘林最小,也随优势树种枝叶氮储量的升高而降低,以白桦林降幅最大,沙棘林最小;群落优势种和群落类型对群落新生枝叶氮储量和氮素利用效率直接作用显著,也受施氮量的影响,进而正向驱动群落新增生物量积累。【结论】华北落叶松林、白桦林和沙棘林3个森林群落新增生物量的差异主要取决于群落类型及其优势种的差异,直接受群落优势种的氮利用效率和新生枝叶氮含量的影响,并受土壤供氮水平的调节;三者的氮利用策略分异表现在氮需求、氮利用效率、环境氮敏感性、饱和氮供应水平4个方面;依次表现为“低需求-高效率-高敏感-低饱和”、“较低需求-低效率-较高敏感-较低饱和”和“固氮型-高需求-低效率-低敏感-高饱和”3个氮利用策略类型,可为不同氮沉降情境或林地氮含量水平下的林分优势树种选择、结构调控和林地精准管理提供依据。

无人机倾斜摄影测量技术在林区植被恢复治理中的应用

林区植被破坏后,需要对破坏区域进行测量评估再实施恢复治理。林区由于树林的遮挡,存在通视困难。信号障碍等难题,使用传统的全站仪、GPS测量方法采集数据较为困难,本文提出,依靠无人机倾斜摄影测量模式获取空间数据,再通过三维建模,最后生成各类成果数据文件。项目实例应用证明本文的测量方法和模式有效,效果良好。

黑龙江森工林区绿色发展模式研究与指标评价

本文从森林资源保护、森林生态系统服务、森林经济发展和森林社会文化发展等方面分析了森工林区的绿色发展模式,提出了森工林区绿色发展模式的指标评价体系,旨在为黑龙江森工林区绿色发展模式的实施提供参考。

Impact of regional human capital and urban sprawl on forest——based on a forest conservation model

Metropolitan cities in China have become a major economic hubs with an unprecedented increase of land use and decline of environmental resources. Based on a simple and abstract forest conservation model, this paper attempts to explain changes of forest resources caused by urban sprawl. Through the research, it is found that high level of regional human capital is beneficial to curb urban sprawl. In this vein the model presents the urban forest conservation cost strategy at the Nash equilibrium of varied discount factor and parameter control.

滇中地区主要森林凋落物有效截留量及其影响因素

[目的]研究滇中地区主要森林类型凋落物有效截留量差异及其影响因素,为该地未来植被恢复和森林管理提供科学支撑。[方法]利用样方调查法、烘干法和浸泡法分析了昆明市双河—磨南德水源林自然保护区内的地带性次生常绿阔叶林(SF)、针阔混交林(TF)、旱冬瓜林(ACF)、华山松林(PA)、成熟云南松林(OPY)、幼龄云南松林(YPY)、银荆林(AD)7种主要森林类型凋落物未分解层(OL)和半分解层(OF)的有效截留量及其影响因素。[结果](1) 7种森林类型凋落物厚度为2.06~7.57 cm,其中OL层1.10~4.30 cm, OF层0.83~3.93 cm,凋落物层厚度排序为TF>ACF>PA>OPY>SF>AD>YPY,凋落物蓄积量为4.75~17.45 t/hm^(2),其中OL层占比为32.02%~62.48%,OF层占比为37.52%~67.98%,凋落物层蓄积量排序为TF>PA>SF>OPY>ACF>AD>YPY。(2)凋落物最大持水率为115.3%~170.7%,初始吸水速率为3.65~5.62 g/(g·h),凋落物持水率和浸水时间的关系可用对数函数y=aln(x)+b表示,吸水速率与浸水时间可用幂函数y=kt~n表示。(3)凋落物最大持水量为7.05~32.19 t/hm^(2),排序为PA>TF>SF>OPY>ACF>AD>YPY,有效截留量为5.45~25.34 t/hm^(2),以TF最高(25.34t/hm^(2)),PA(24.99 t/hm^(2))和SF(24.62 t/hm^(2))次之,YPY最低(5.45t/hm^(2)),影响有效截留量的场地特征主要为蓄积量、自然含水率、分解强度以及厚度,影响有效截留量的水动力过程主要是最大失水量、前6.0 h平均吸水速率和前2.0 h平均吸水速率。[结论]滇中地区未来植树造林应以针阔混交林为主,注重对地带性次生常绿阔叶林的保育,采取辅助自然更新的措施促进人工纯林向混交林演化,同时减少踩踏、收集凋落物等人类活动的干扰,从而增加森林生态系统凋落物的水源涵养能力。

晋西黄土区典型人工林土壤水分的垂直分布特征

【目的】探究晋西黄土区人工林恢复过程中0~500 cm土层土壤含水量垂直特征,为改善人工林土壤水环境,实现林水平衡提供理论依据。【方法】以晋西黄土区蔡家川流域5种典型人工林(刺槐Robinia pseudoacacia、侧柏Platycladus orientalis、油松Pinus tabuliformis、刺槐-侧柏、刺槐-油松)为研究对象,通过土钻烘干法测定0~500 cm土层土壤含水量,分析人工林土壤含水量的垂直特征。【结果】研究区典型人工林平均土壤含水量由大到小依次为侧柏、刺槐-侧柏、油松、刺槐-油松、刺槐,5种人工林土壤含水量差异显著(P<0.05),降水量及土壤质地是影响人工林土壤含水量的主要因素;在垂直方向上,人工林土壤含水量变异程度均为中等变异,变异系数随土层深度的增加呈减小趋势,约在360 cm土层形成稳定变化,人工植被主要影响0~360 cm土层内的土壤水,5种人工林中刺槐林地土壤水分变异程度最大,侧柏林地土壤水分最为稳定;采用有序聚类法将人工林土壤水分垂直层次划分为交换层、利用层、调节层和稳定层,不同林分间层次划分深度存在一定差异。【结论】研究区人工林可导致土壤含水量一定程度的减少,刺槐、油松、刺槐-油松林会加剧对深层土壤水分的消耗,其中刺槐林对深层土壤水分的消耗最为明显,建议在林业生态工程建设时,适当减少刺槐林面积,提高侧柏栽植比例。对现存土壤含水量较低的刺槐林,通过间伐降低林分密度,或将其改造为混交林,以期改善土壤水环境,实现林水平衡。