山地型旅游城镇土地利用变化特征及其驱动机制——以井冈山市为例

文章基于多期遥感影像,研究了井冈山市2007-2013年的土地利用变化情况,结果发现:1)建设用地是相对变化较大的土地利用类型,呈现出沿交通线向外围不断拓展的空间分布趋势; 2)旅游基础设施和服务设施用地不断增加,使林地、耕地等向旅游用地不断转化; 3)自然地理环境、交通可达性等因素显著影响了相关城镇土地利用变化,并由此形成了综合发展型、景区主导型、交通主导型和传统村镇型4种旅游用地模式。这说明旅游业的快速发展对井冈山市城镇土地利用变化产生了重要影响,并给其生态环境带来较大压力,相关政府部门应加以合理管控。     

喀斯特城市新区土地利用时空演变研究——以贵阳市观山湖区为例

为探究喀斯特城市新区的土地利用时空演变特征、趋势和强度,基于2010、2015和2020年3期遥感影像,结合ArcGIS等空间分析技术及动态度模型,从土地利用数量结构、空间格局和动态度方面分析了喀斯特城市新区观山湖区2010～2020年土地利用时空变化特征。结果显示：观山湖区在研究期内各类土地利用变化显著,耕地、水域、草地以及未利用地的面积持续减少,其中下降幅度最大的是耕地面积,林地和建设用地面积不断增长。空间变化呈现中部耕地锐减和建设用地以原金阳新区为中心向西南方向扩张的显著特征。根据研究结果提出了研究区土地资源可持续利用的对策建议：进一步合理规划土地利用、缓解城市化进程中的人地矛盾以及科学开展生态治理。     

基于CA-Markov和InVEST模型的生境质量时空演变及预测——以武汉市为例

以长江经济带核心城市武汉为研究区,基于2010年、2015年、2020年的土地利用数据,使用CA-Markov模型和InVEST模型并结合LEI值,探究了土地利用变化所引起的生境质量演化特征,以及两者之间的影响力与关联性。结果表明：(1)2010-2020年,研究区的土地利用类型以耕地、水体和建设用地为主,耕地面积逐年减少,建设用地面积逐年增加。武汉市作为全国重要的工业基地和内陆最大的水陆空交通枢纽中心,以厂矿、大型工业区和交通道路为主的其他建设用地类型的增加比例最大,大量高生境质量的土地利用类型向低生境质量转化,城市整体的生境质量等级一直处于下降趋势。(2)2020-2025年,研究区内土地利用格局和生境质量的演变趋势与2010-2020年基本一致。生境质量较低的地类由城市中心向四周逐渐蔓延,中心城区的生境质量基本处于低等级,只有少数湖泊湿地附近的生境质量为中或较低等级。     

内蒙古阴山北麓农牧交错区土地利用动态分析及预测

基于阴山北麓农牧交错区2000年、2005年、2010年、2015年四期土地利用遥感监测图,利用ARCGIS和IDRISI软件分析了区域土地利用格局及其时空变化规律和变化趋势,并用CA-Markov模型对2020年的土地利用变化趋势进行了模拟。结果表明:(1)草地、耕地和未利用地为研究区的优势地类,2000-2015年耕地面积逐渐减少,主要转化为林地和草地;林地、居民工矿用地面积逐渐增加;草地面积在2000-2010年逐渐增加,2010-2015年又显著减少,主要转化为未利用地;未利用地面积在2000-2010年逐渐减少,2010-2015年又呈增加趋势;水域面积没有发生显著的变化。(2)2000-2005年由于生态工程实施的扰动,使得土地利用处于调整期;2005-2010年土地利用处于稳定期;2010-2015年土地利用处于衰退期。(3)2020年土地利用的变化趋势和2010-2015年这5年间的变化趋势大体相同,主要变化发生在草地和未利用土地上,但变化幅度显著增加。     

河北省唐县土地利用分区及重心迁移规律

土地利用分区及重心迁移规律研究对区域土地合理利用与科学管理有重要意义。文章将土地利用类型按照主导功能划分为建设区、粮产区、生态区、潜力区4种用地功能区。采用土地利用转移矩阵研究唐县土地利用变化情况,采用重心迁移理论研究唐县土地利用功能区转变规律。结果表明:(1)2009-2015年,研究区建设用地面积显著增加,水域、林地、园地面积明显减小。耕地转出方向主要为其他土地和建设用地,分布在南部平原地带,耕地转入方向主要为水域和其他土地,分布在西大洋水库和唐河流域;其他土地主要转出方向为耕地和建设用地,主要转入方向为耕地。(2)唐县土地利用功能区转变规律明显,2009-2015年,建设区日趋扩张,增加了232.17hm~2;生态区日趋缩减,减少了457.1hm~2;各土地利用功能区重心均发生明显偏移,其中,建设区、潜力区重心分别向东南方向迁移237.4m、278.4m,粮产区、生态区重心分别向西北方向迁移221.5m、549.8m。(3)建设区中心城镇在原基础上向外扩张,并沿道路迅速发展;粮产区向西北方向压缩生态区,同时南部粮产区被建设区挤占;生态区逐渐被压缩。     

基于土地利用时空格局演变的新乡市生态风险分析

高速的城镇化发展使新乡市的生态环境逐步脆弱,基于土地利用时空格局演变的生态风险研究旨在为新乡市的土地结构优化及生态建设提供科学的理论依据。文章以新乡市2000年、2010年、2020年土地利用数据为基础,构建生态风险指数,采用ArcGIS空间分析法对新乡市的土地利用类型及土地利用时空格局演变下的生态风险变化特征进行分析。结果表明：1)2000—2020年新乡市的土地利用类型及面积发生不同程度的变化,耕地作为优势景观,面积不断缩小;林地面积先增加后减少,但总量趋于平稳;草地不断退化,面积不断缩小;建设用地的面积呈现持续增长的状态,城市的建设加快了土地利用类型的变化速率。2)由于城市用地极速扩张,耕地成为主要土地转出类型,大幅转化为建设用地且转化比例逐渐增大。3)新乡市的土地利用生态风险异质性显著且呈上升趋势,但低生态风险区占主导地位,高生态风险区主要位于城市中心的建设用地并呈放射状向周边辐射,较低生态风险区主要位于研究区北部,较高生态风险区主要位于南部水域,受人为干扰较多。总之,新乡市的生态风险与土地利用类型及转换速率保持一致并呈现非正向发展,亟需对新乡市的生态环境状况进行合理改善。     

2000—2010年辽河流域景观格局动态分析

以2000年、2005年、2010年土地利用数据,运用地理信息系统,采用景观转移矩阵、景观指数、土地利用动态度,kappa指数方法,对辽河流域10 a间的景观格局变化进行综合研究,并对辽河流域内所包含的各市辖区县的土地利用度进行分析。结果表明:研究区景观主要以耕地、林地为主。2000—2010年间,各个景观存在不同程度的变化,其中耕地大幅度减少,城镇用地大幅度增加,城镇用地主要由耕地、湿地转化而来;土地利用度及土地利用动态度逐年提高,市辖区的土地利用度明显高于各县;景观指数与Kappa指数表明:主要类型的景观变化幅度较小,景观总体变化趋势趋于复杂,破碎化加剧,人为影响突出。     

城镇化背景下洱海上游土地利用演变过程分析

近年来,洱海流域社会经济发展迅速,城镇化进程加快,土地利用发生了较大变化。研究长时间序列洱海上游的土地利用演变过程,分析其与城镇化进程的耦合关系,具有重要意义。以洱海上游1975,1985,1995,2005和2015年遥感影像为基础数据,提取了各时期土地利用斑块信息,计算了土地利用转移矩阵,借助土地利用动态度模型、信息熵模型和分形模型,定量描述和分析了洱海上游土地利用的演变过程。结果表明:1)近40年间,洱海上游以林地、农田和灌草丛为优势地类,建设用地面积呈持续增加趋势,整体上土地利用综合程度处于中等水平;2)转移变化方面,主要以灌草丛的转出和建设用地的转入为典型特征,单一类型的动态度变化较小,其中建设用地的动态度变化较为明显,其面积处于增加趋势;3)洱海上游1975—2015年间的土地利用斑块信息熵、均衡度及稳定性亦发生了相应变化。分析研究城镇化背景下洱海上游土地利用演变特征,对于提升土地集约化程度,合理规划管理土地资源,科学制定经济发展政策,促进土地的科学与可持续利用,加快城镇可持续发展具有重要的指导意义。     

滇池流域土地利用动态变化分析

在RS和GIS的支持下,获取了滇池流域1998年、2002年及2010年的土地利用分类图,通过土地利用动态度方法,分析了流域22年间土地利用类型的数量变化。结果表明：耕地和建设用地主要沿滇池分布,林地面积所占比例较大;土地利用类型变化主要发生在耕地、未利用地、建设用地,其土地利用动态度分别为1．598％、2．698％和9．021％;人口增长和经济的快速发展是滇池流域土地利用／覆被变化的主要驱动力。     

基于遥感影像的太原土地利用频度变化分析

以山西太原为研究区,基于ArcGIS平台应用重编码和重分类的方法,对太原市2000年、2005年、2010年、2015年4个时相下的土地利用变化和变化频度进行了分析,并得出了相关结论：(1)2000～2005年太原市土地利用类型变化中,建设用地面积增加最多,表明政府大力发展经济建设,建设用地面积的变化和经济发展水平、人口密度等密切相关;(2)研究时段内,耕地变为建设用地的面积占比较大,应注重粮食安全和城市的健康发展;(3)2000～2015年水域面积没有明显的变化,表明在城市发展过程中,注重水资源的涵养,没有盲目占用水域面积。基于太原市土地利用变化情况,对区域土地资源管理、社会经济发展规划等土地利用提供决策依据具有重要意义。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.