Spatial assessment of forest cover and land-use changes in the Hindu-Kush mountain ranges of northern Pakistan

Anthropogenic activities and natural processes are continuously altering the mountainous environment through deforestation, forest degradation and other land-use changes. It is highly important to assess, monitor and forecast forest cover and other land-use changes for the protection and conservation of mountainous environment. The present study deals with the assessment of forest cover and other land-use changes in the mountain ranges of Dir Kohistan in northern Pakistan, using high resolution multi-temporal SPOT-5 satellite images. The SPOT-5 satellite images of years 2004, 2007, 2010 and 2013 were acquired and classified into land-cover units. In addition, forest cover and land-use change detection map was developed using the classified maps of 2004 and 2013. The classified maps were verified through random field samples and Google Earth imagery(Quick birds and SPOT-5). The results showed that during the period 2004 to 2013 the area of forest land decreased by 6.4%, however, area of range land and agriculture land have increased by 22.1% and 2.9%, respectively. Similarly, barren land increased by 1.1%, whereas, area of snow cover/glacier is significantly decreased by 21.3%. The findings from the study will be useful for forestry and landscape planning and can be utilized by the local, provincial and national forest departments; and REDD+ policy makers in Pakistan.

The relationship between soil,climate and forest development in the mid-mountain zone of the Sangong River watershed in the northern Tianshan Mountains,China

The mountainous forests in arid regions, being sensitive to climate change, are one of the key research topics related to the mechanism of interaction between climate and the terrestrial ecosystem. In this study, the spatial distribution of a mid-mountain forest and its environmental factors were investigated by using a combination of remote sensing technology, field survey, climate indices and soil nutrient analysis in the Sangong River watershed of the northern Tianshan Mountains. The forest （Picea schrenkiana） was distributed between 1,510 and 2,720 m asl. Tree height and diameter at breast height （DBH） exhibited a bi-modal pattern with increasing elevation, and rested at 2,450 and 2,250 m asl, respectively. The two maxima of DBH appeared at 2,000 and 2,550 m asl, and the taller trees were observed at 2,100 and 2,600 m asl. For the annual mean temperature, the difference was approximately 5.8℃ between the lowest and the highest limits of the forest, and the average decreasing rates per hundred meters were 0.4g℃ and 0.55℃ with increasing altitude between 1,500 and 2,000 m asl and above 2,000 m asl, respec- tively. The annual precipitation in the forest zone first increased and then decreased with the increase of altitude, and the maximum value was at 2,000 m asl. For per hundred meters, the annual precipitation increased with the rate of 31 mm between 1,500 and 2,000 m asl and decreased by 7.8 mm above 2,000 m asl. The SOM, TN and TP were high between 2,000 and 2,700 m asl and low at the lower and upper forest limits. The minimum CaCO3 con- centration, pH value and EC coincided with the maximum precipitation belt at 2,000 m asl. The SOM, TN and TP were high in the topsoil （0-10 cm） and differed significantly from the values observed in the deep soil layers （〉10 cm）. The soil nutrients exhibited spatial heterogeneity and higher aggregation in the topsoil. In conclusion, soil and climate are closely related to each other, working synergistically to determine the development and spatial distribution of the mid-mountain forest in the study area. The order of the importance of environmental factors to forest development in this study is as follows： soil nutrients〉precipitation〉elevation〉temperature.

Current vegetation dynamics of the “forest-mountain tundra” ecotones of Lake Baikal coastal ranges

During last decades, new trends appeared in the ecotones of the upper boundary of forests at the ridges surroundingLakeBaikal(Khamar-Daban and Baikal’sky Ridge): ones to advance of wood species (Pinus sibirica Du Tour, Abies sibirica Ledeb., Larix sibirica Ledeb., Larix dahurica Lawson) out of timber stands into the area of subgoltsy with Pinus pumila (Pallas) Regel. up to mountain tundras. In average, this is from 100 to 200 - 300 meters (maximum up to500 m) in linear distance from the margin of dense timber stand. A burst of forests renewal occurred in 1989-1995, it resulted probably from a high productivity of the seeds of wood species due to warmer winters in 1980ies-1990ies which favoured the formation of favourable climate-edaphic conditions for the development of forest communities above the forests boundary on the ridges surrounding Lake Baikal.

干旱区气候变化及其对山地森林生态系统稳定性和水文过程影响研究进展

在干旱区,水是形成绿洲的根本要素。干旱区高寒山地是维系西北干旱区绿洲存在、是当地国民经济持续发展和生态环境稳定的水源地,山地森林生态系统具有重要的涵养水源功能,有“绿色水库”之称。气候变化将改变山地生态系统结构、组成和水循环,加剧水资源短缺,威胁干旱区绿洲安全。回顾并综述了干旱区气候变化及其对干旱区山地森林生态系统稳定性和水文过程的影响研究进展,指出了研究中存在的问题,并提出未来在干旱区山地仍需要评估优于1 km空间分辨率的气候变化趋势,从多尺度、多界面、多学科、多方法开展气候变化对干旱区山地森林生态系统稳定性和水文过程影响的综合研究,以促进干旱区山地生态学的发展,为干旱区管理部门提供适应和缓解气候变化、科学的制定气候变化条件下水资源管理方案、实现水资源的有效管理奠定理论基础,促进干旱区气候变化条件下的环境和社会经济可持续性发展。

北京山区森林经营探讨——以门头沟区为例

为提高北京山区森林健康状况和森林质量,更好地发挥首都绿色生态屏障作用,以门头沟区为例,基于北京市第9次森林资源调查数据,通过对实地资料收集、文献查阅、现场调查等方法与手段,系统分析与评价了门头沟区森林资源现状、资源变化及目前森林经营中存在的问题。在此基础上,结合区域功能定位、森林资源结构、经营管理水平和经济社会状况等特点,提出了森林经营分类、生态修复、森林保护、森林资源多功能利用4方面山区森林经营措施、建议与对策,为森林可持续发展与健康经营提供科学依据与理论支撑。

Multi-scale analysis of trade-off/synergistic effects of forest ecosystem services in the Funiu Mountain Region,China

The trade-offs and synergies of forest ecosystem service are important research topics for several disciplines.The multi-scale analysis of service trade-offs and synergies assists in the implementation of more effective forest resource management.Based on multi-source data including forest distribution,topography,NDVI,meteorology and soil conditions,key forest ecosystem services,including total forest volume,carbon storage,water yield,soil retention and habitat quality were mapped and evaluated for the Funiu Mountain Region through integrated deployment of the CASA model,the InVEST3.2 model and the ArcGIS10.2 software.The characteristics of trade-offs and synergies among different ecosystem services were then mapped and considered across multiple spatial scales(i.e.,by region,north and south slopes,vertical belt)using the spatial overlay analysis method.The main results are as follows:(1)Mean forest volume is 49.26 m^(3)/ha,carbon density is 156.94 t/ha,water yield depth is 494.46 mm,the unit amount of soil retention is 955.4 t/ha,and the habitat quality index is 0.79.(2)The area of forests with good synergy is 28.79%,and the area of forests with poor synergy is 10.15%,while about 61.06%of forests show severe trade-offs and weak trade-offs.The overall benefits of forest ecosystem services in the study area are still low.In the future,bad synergy and severe trade-off areas should be the focus of forest resource management and efficiency regulation.(3)Synergy between ecosystem services is better for forest on south slope than that on north slope.Deciduous broad-leaved forest belt at moderate elevations on south slope in the mountains(SIII)has the highest synergies,while that at low elevations on north slope(NI)exhibits the lowest synergy levels.

清代赣南山区移民的山林经营--以张家地周氏文书为例

赣南山区为明清之际移民的山区开发活动提供了广阔的舞台,在此过程中,移民的山林经营方式是山区社会经济史研究的重点内容之一。发现于兴国县张家地的周氏文书种类丰富,涉及山林交易文书繁多,以此为切入点,能够展现兴国张家地周氏山林经营的情况,揭示周氏山林经营具有跨行政区交易,山林、房屋、田地混合交易,利用山林资源进行融资等特点。周氏的山林经营方式是赣南山区开发的一个缩影,其个案对于探讨赣南山区不同的林业财产形态与交易方式,揭示中国传统山区社会与外来移民家族之间的互动关系有着重要意义。

Study on Soil Moisture Distributing Characteristics of Artificial Forest in Mountainous Region

Physical characteristics of soil structure and soil moisture of five kinds of artificia! forests were researched in Shengquan Temple Forestry Farm, in the southern mountainous area of Jinan City, in order to offer scientific management and nurture of forest vegetation in mountainous area of North China. Results indicated that： （1） In these artificial forests researched, some indexes expressing soil pedonydrological physical character, such as soil density, porosity, infiltration rate, were much better than those in bare land, and these indexes Showed this order： mixed forest 〉 pure forest, Kalopanax pictus 〉 Koelreuteria paniculata 〉 Pistacia chinensis. （2） In dry and rainy seasons, with the increasing of soil depth, soil water content decreased in most parts of forest, and their extent of change was less than those in bare land. （3） With the increasing of soil depth, soil saturated water content decreased in all kinds of forests. Water storing capacity of surface soil layer was the best in the mixed forest, while differences were little in other forest. Water storing and adjusting capacity was good in the mixed forest, while water offering capacity had little discrepancy in all forests. Conclusions show that judging from water conservation and water use efficiency, mixed forest is better than pure forest, and in pure forest K. pictus is better than K. paniculata. Therefore, it is proposed that in the future, mixed forest should be fostered and managed firstly, the species being made up of K. pictus and P. chinensis. In the pure forest, K. pictus is much better than others. Nowadays K. paniculata, and P, chinensis, especially their soil surface vegetation and litter, should be protected. As to poor forest, closing hill for afforestation should be adopted. Poor forest have better be reconstructed to be mixed forest in available conditions.

基于植被覆盖度变化的山东泰山区域生态修复工程效果研究

采用最大值合成法、像元二分模型和趋势分析法,以NASA发布的2017—2022年MODIS NDVI 16d最大值合成数据为基础数据,通过植被覆盖度变化趋势对山东泰山区域生态修复工程整体效果进行研究。结果表明:2017—2022年泰山区域NDVI最大值和平均值总体呈波动上升趋势,最大值增长率为0.0055/a,平均值增长率为0.0049/a。山东省泰山区域Slope平均值为0.00478,生态修复工程绝大多数所处像元植被覆盖度变化率大于0,说明整个区域植被覆盖度有所改善,工程有明显效果。

内蒙古大兴安岭不同下垫面浅层地温的变化特征及其对气温的响应

基于鄂温克自治旗站和图里河站2005—2022年的实测地温和气温资料,采用线性倾向估计、Mann-Kendall检验等方法,系统分析该地区地温的时间演变规律及对气温变化的响应。结果表明:草原区和林区的各年平均气温均低于同时期的各层地温。草原区和林区的地温均随土层的加深而降低。林区年浅层地温气候倾向率大于草原区的年浅层地温气候倾向率。草原区春季气温变化对其年气温变化有显著影响;林区春、冬两季的0~20 cm浅层地温变化对年浅层地温变化有较大贡献;春、夏两季,草原区和林区浅层地温变化均与气温变化有较强的相关性。冬季,两站浅层地温变化对气温变化均不敏感,这可能是由于地表受到不同程度积雪覆盖的影响。草原区年平均浅层地温变化与气温变化的相关关系不明显,林区0~20 cm年浅层地温变化与气温变化呈较强的相关性。

天然林资源保护工程对长白山林区森林生态系统服务功能的影响

森林生态系统具有多种服务功能,对生态安全、生物资源和生存环境的保护、实现社会经济可持续发展起着重要的作用。依据国家林业局发布的《森林生态系统服务功能评估规范》(LY/T1721—2008),对涵养水源功能、保育土壤功能、固碳释氧功能、积累营养物质功能、净化大气功能5个方面进行评价,量化揭示天然林资源保护工程实施对长白山林区森林生态系统服务功能物质量及其价值的影响。结果表明:从1998年开始试点,到2010年一期正式结束,森林生态系统各项服务功能的物质量和价值量均呈现增加趋势。在涵养水源功能方面,调节水量增加了657.28×104m3,累计增加价值为113.45亿元;在保育土壤功能方面,固土量增加了4.6×104t,土壤中减少的氮流失0.02×104t,减少的磷流失0.01×104t,减少钾流失0.01×104t,累计增加价值为2.92亿元;在固碳释氧功能方面,固碳量增加了0.64×104t,释氧量增加了0.36×104t,累计增加价值为0.11亿元;在积累营养物质功能方面,固氮量、固磷量、固钾量均增加0.01×104t,累计增加价值0.3亿元;在净化大气功能方面,吸收二氧化硫、氟化物、氮氧化物、滞尘量分别增加24.71×104kg、0.64×104kg、1.08×104kg、1962.76×104kg,累计增加价值5.09亿元。森林生态系统服务功能价值总量增加了121.87亿元,平均每年增加约10亿元,超过工程每年各项投资之和。价值量增加额度依次为:1)涵养水源功能;2)固碳释氧功能;3)保育土壤功能;4)净化大气功能;5)积累营养物质功能。这些增加量只有一部分为工程区当地利用,其余都贡献到全国乃至全球。因此,及时制定和启动生态补偿等一系列政策和措施,将对更好的实施天然林资源保护工程、实现林区的可持续发展具有重要作用。

大岗山林区几种常见灌木生物量估算与分析

以江西省大岗山年株林场常绿阔叶林、人工杉木林、天然毛竹林3种典型森林类型为研究对象,调查研究了10种分布较广泛的灌木树种的高度、基径、冠幅范围和干湿比,通过回归分析构建各物种以植冠面积(A)、植株体积(V)、基径与株高乘积(DH)、基径平方与株高乘积(D2H)等为自变量的最优器官和全株生物量模型,并用最优模型对不同森林类型下这10种灌木生物量情况进行了研究。结果表明,单一物种器官和全株生物量最优模型多为二次或者三次方程,叶生物量最优模型采用的自变量多为V或者A,干、枝最优模型采用的自变量多为DH、D2H或者V,根最优模型采用的自变量多为D2H和V,全株生物量最优模型采用的自变量多为D2H或者V。常绿阔叶林、人工杉木林、天然毛竹林下这10种灌木的总生物量分别为1 284.38、1 088.08、968.13 kg·hm-2。

祁连山林区积雪分布规律调查

以祁连山西水林区排露沟流域为代表研究祁连山林区春天积雪分布规律 ,表明祁连山林区积雪分布与海拔高度关系极大 ,海拔越高 ,积雪越多 ;在较小尺度上 ,积雪分布与坡向、植被类型、林分郁闭度等因子有关 ,主要受森林植被影响 ,森林植被形成积雪小环境。

鲁中花岗岩山区人工林土壤水分物理性质

在济南市南部山区圣泉寺林场内,以5种人工林为研究对象,对其土壤物理结构和土壤水分特征进行研究,以其为北方石质山区人工林的科学经营与抚育管理提供依据。结果表明:①各种林分的土壤密度、孔隙度和渗透速率等表征土壤水文物理性质的指标明显好于无林地,其中混交林好于纯林,刺楸纯林好于黄连木、栾树纯林。②在旱季和雨季,随着土壤深度的增加,大部分林地土壤含水量呈现递减趋势,其变动幅度小于无林地。③随着土壤深度的增加,各林地土壤饱和持水量逐渐减小;混交林表层土壤蓄水功能最好,其它林分各层次差异较小。混交林对水分的贮蓄和调节能力较强,但各林分供水性能差别不大。在涵养水源和水分有效性方面,混交林优于纯林,纯林中以刺楸大阔叶树种较好,栾树较差。建议在今后的森林经营中,首先考虑营造混交林分,林种组成以刺楸×黄连木较好;若营造纯林以刺楸林分较好。在现有林分的经营管理中,对黄连木和栾树纯林应注重对其地表植被和枯枝落叶层进行保护,对残次林分采取封山育林措施,有条件时尽量改造为混交林。

秦岭火地塘林区油松群落乔木层的碳密度

为精确估计秦岭火地塘林区油松群落乔木层的碳储量,在外业调查的基础上,采用TOC-VTH-2000A型TOC分析仪测定了油松(Pinus tabulaeformis)、华山松(Pinus armandi)、锐齿栎(Quercus alienavar.acuteserrata)、华北落叶松(Larixprincipis)干、皮、枝、叶、根的含碳率,结合已建立的乔木不同器官生物量模型,计算了不同树种各器官的碳储量和乔木层的碳密度,分析了不同含碳率下各树种各器官碳储量的差异。结果表明:不同树种各器官含碳率明显不同;在相同生物量下,以实测含碳率、0.45和0.50作为植物的平均含碳率计算的油松的干、皮、枝、叶、根,锐齿栎的枝,华北落叶松的皮、枝、叶、根的碳储量有显著差异;油松群落乔木层碳密度为6.594 Mg.hm-2。

闽南山区连续年龄序列桉树人工林土壤养分动态

对闽南山区连续年龄序列(2a、3a、4a、5a、6a)的尾巨桉(Eucalyptus urophylla×E.grandis)人工林土壤有机碳及氮、磷、钾含量进行了分析,以评价土壤养分随林分年龄的变化动态.土壤有机碳、全氮、水解氮、全磷、速效磷均表现出随林分年龄增加而增加,到4a生时达到最大,随后则呈下降趋势,6a生时下降到最低值.速效钾含量则随林分年龄增加逐步下降,6a生林分0～20cm、20～40cm和40～60cm这3个土层速效钾含量分别比2a生下降了53.2%、44.4%和55.2%;土壤全钾含量也表现出一定的下降趋势.所有年龄林分的土壤有机碳、全氮、水解氮、全磷、速效磷和速效钾含量均随土层深度增加而降低,而土壤全钾则表现出相反的趋势.因此,在桉树人工林经营过程中,应定期增施钾肥,适时施用有机肥及氮、磷肥,以控制地力衰退.

林窗对日本落叶松人工林林下植物多样性的短期影响

采用样方法调查了鄂西建始县国有长岭岗林场日本落叶松人工林林窗及林下植物多样性,运用4种常用的物种多样性指数分析了林窗干扰对日本落叶松人工林植物多样性的影响。结果表明：林窗内木本植物和草本植物的物种数、Shannon-wiener指数、Simpson指数显著高于非林窗,Pielou指数亦高于非林窗,但差异不显著;不同大小级林窗的物种多样性表现出中林窗（50~100 m2）〉小林窗（〈50 m2）〉大林窗（〉100 m2）;林窗内物种多样性高于非林窗,但林窗中的木本植物和草本植物的优势种不明显,处于种群间竞争与共存阶段。日本落叶松人工林草本植物的多样性高于木本植物,林窗对林下植物多样性的影响主要是通过影响草本层而引起的。在森林经营实践中,要重视草本植物在林窗形成初期对人工林生物多样性的拓展作用,并通过模拟林窗干扰实行群团状择并在林窗中补植阔叶树种,提高鄂西山区日本落叶松人工林的植物多样性。

滇中高原山地防护林体系水土保持效益研究

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