Influence of historical land use on present-day forest patterns: A case study in south-western Germany

Two major questions were investigated in this study: (1) What are the contributions of historical in comparison with natural factors to the development of present-day forest patterns? (2) What implications can be drawn from an understanding of forest patterns and historical land-use development with regard to landscape planning and nature conservation? The Sandstein-Spessart, a natural unit in south-western Germany, served as an example to show the influence of different types and intensities of land use on the differentiation of the natural landscape. The methodological approach to this study was a synthesis of previously available information. It was shown that different initial site conditions within the natural unit such as geology and climate led partly to the spatial differentiation of the present-day landscape. However, economic and political factors such as the glasswork industry and hunting activities also played a major role in the development of different forest patterns. Examples are given of how this synthesis of landscape ecology and landscape history can provide a useful basis for nature conservation and landscape planning.     

河北省平山县卸甲河流域各土地系统植被的比较研究

以河北省平山县卸甲河流域作为个例研究,划分了８个土地系统。在研究了各土地系统土地利用类型结构的基础之上,进一步比较了它们之间植物群系（林）的分布：植物种数量,乔木、灌木及草本植物状况,以及植物群系的组成结构。各土地系统之间差别很大。研究说明,封山育林、植树造林恢复植被,以及保护天然林,是保护生物多样性唯一有效的办法。另一方面,也说明生态土地分类注意人类影响程度和土地利用,更加易于和土地分类规划相结合     

Effect of terrain on landscape patterns and ecological effects by a gradient-based RS and GIS analysis

Terrain is an important environment factor that plays a vital role in human development by influencing the spatial layout of land use patterns. The terrain niche index, combined with slope and elevation, can comprehensively present detailed information about spatial differences in terrain and is superior to single terrain factors. We applied remote sensing and geographical information system to terrain gradient, used the non-dimensional distribution index to examine spatial distribution characteristics of various landscape types, and analyzed the ecological effects of landscape were quantitatively on terrain gradients. Eco-environment quality (EEQ) was evaluated using the forestry operation area as the evaluation unit. The spatial distributions in various landscapes were significantly influenced by terrain factors, especially by bodies of water, cropland and residential land. The spatial distribution varied greatly in different terrain gradients for similar landscape types. The areas associated with good, intermediate and poor EEQ were occupied primarily by natural landscape, semi-natural and largely artificial landscapes, respectively.     

半干旱黄土丘陵区不同土地利用类型植物物种多样性研究

【目的】为了更好地利用半干旱黄土丘陵区的土地资源,促进该区域植被恢复,提高生物多样性,使区域生态环境有所改善。【方法】以半干旱黄土丘陵区龙滩流域的植被为研究对象,对该流域11种典型的土地利用类型(2种农地、自然荒草地、人工牧草地、撂荒草地、灌木林地、5种乔木林地)的植被物种组成和多样性进行了调查研究。【结果】流域内共调查到种子植物56科166属254种,其中裸子植物门3科7属13种,占流域总科、总属、总种的5.36%、4.22%、5.12%;被子植物门53科159属241种,占流域总科、总属、总种的94.64%、98.78%、94.88%。在被子植物门中,双子叶植物纲有50科134属205种,单子叶植物纲有3科25属36种,两纲物种分别占流域总种数的80.71%和14.17%,占该门物种总种数的85.06%和14.94%。不同土地利用类型植被多样性分析结果表明,物种丰富度表现为农地物种丰富度低,人工牧草地、撂荒草地和灌木柠条林地居中,乔木林地(山杏、山毛桃、油松、侧柏、青杨)和天然荒草地高;物种多样性表现为马铃薯农地的物种多样性低,覆膜农地、人工牧草地、撂荒草地及灌木柠条林地居中,自然荒草地和乔木林地比较高;物种均匀度表现为农地、撂荒草地、人工牧草地及灌木柠条林地的均匀度高,自然荒草地居中,乔木林地低。【结论】不同土地利用方式和植被演替恢复时间差异是产生植被多样性差异的基础,也是该区域植被恢复和物种多样性保护需要考虑的重要要素。     

Natural reforestation is changing spatial patterns of rural mountain and hill landscapes: A global overview

The present landscape structure and function is the result of centuries of changes produced both by natural processes and human driving forces. For centuries many mountain and hillside areas have been the subject of deforestation to create space for agriculture and grazing, although the abandonment of traditional mountain agriculture has produced a natural forest recovery in many regions of the world. The physical changes imposed on the landscape by the development of secondary woodland have brought both positive and negative consequences, depending on the geographical and economic context and on the scale of the sites. Among the ecological problems caused by natural reforestation, one of great interest is the reduction of open spaces resulting in a loss of landscape heterogeneity and mosaic features. This review paper focused its attention on landscape metrics or indices that are frequently used to assess the structural characteristics of the landscape and to monitor changes in land use: mean patch size (MPS), connectivity (CONN), boundary length (BL) and the patch number (NP). Through the analysis of 52 selected papers and 53 case studies, we identified the main gaps in current knowledge, providing directions for further research. Most of the reviewed studies focused only on a portion of the spatial attributes that we were interested in and only 32 case studies reported accurate data both on forest expansion rate and time range analyzed in the study area. We conclude that the study of changes in all the spatial attributes considered within the same case study is a key to explain ecological consequences in mosaic cycles or in stochastic dynamic landscapes that emerged from the interplay of several processes, and to predict and explain their spatial and temporal characteristics. The current knowledge of how changing spatial attributes affect biodiversity, habitats, and ecosystem functions is limited by the scarcity of studies that explicitly consider the shifting in time of the four spatial attributes together.     

金沙江干热河谷稀树灌草丛植被恢复方式研究

论述了金沙江干热河谷稀树灌草丛植被区自然概况,植物群落演替基本理论及封山育林(自然演替)与人工造林(人工促进恢复)2种恢复方式区基本情况。通过对比研究,结论是：封山育林自然演替3年后的稀树灌草丛,植物群落比人工促进恢复方式的复杂,生物多样性体现较好,灌木类逐渐转向耐旱、耐热、耐火、更新力强的抗逆类型发展,每获得1kg生物量的投入是人工播种方式的1／3。     

贵港君子垌客家传统聚落山水空间营建研究

以君子垌客家传统聚落为研究对象,以其营建过程中的人地互动和营建方式导向下形成的聚落景观格局为研究内容,采用文献研读、实地调研、系统分析相结合的方法,梳理归纳了聚落的水利系统、土地开发格局和居住空间格局,并对自然环境与社会文化特性相结合而营造出的人文景观进行了分析,以此来客观解读客家聚落景观蕴藏的耕读并行、重视宗社的文化...     

退耕坡地系统生态综合评价中几个景观生态学问题

退耕坡地系统属于退化土地生态系统,大部分是毁林(草)开荒形成的,是人为加速了自然生态系统的逆行演替而形成的低产脆弱的生态系统。对退化生态系统进行综合整治与恢复,以及人工生态系统的重建的理论基础是生态演替和人为设计理论。退耕还林(草)是通过一定的社会物质和能量的投入定向加速景观生态系统的演替过程。评价退耕地的生态经济效益是退耕还林(草)工程的重要组成部分,重点评定项目是否实现预期目标、项目的产出、效果和影响。本文应用景观生态学的理论:景观尺度与等级理论、景观空间格局与异质性理论、景观演化与干扰理论探讨了退耕地生态评价的内容、方法和应注意的问题,从而为退耕还林(草)工程的顺利进行提供有力的保障。     

Spatio-temporal dynamics of <Emphasis Type="Italic">Quercus faginea</Emphasis> forests in the Spanish Central Pre-Pyrenees

Anthropomorphic changes in land use have extensively modified natural forests in the European countries over the twentieth century. This yielded a decline in the number of plant species and fragmentation of their populations. Understanding of the impact of land use changes on the spatio-temporal dynamics of forest species is essential to the ecological sustainability of the natural forests in the region. In this study, we examined the spatio-temporal dynamics of Q. faginea forests in the Central Pre-Pyrenees (Spain) over period from 1957 to 2006. Gains and losses in Q. faginea forests were quantified by means of construction of matrix of changes. Patch fragmentation, isolation, and irregularity were assessed using a set of standard landscape metrics. Also, the probable factors influencing these changes were identified employing three statistical models. The univariate generalized additive model (GAM) was used to explore the nature of the relationship between the response and predictor variables. The Bayesian model averaging (BMA) and the adaptative regression mixed with model screening (ARMS) were employed to identify the most important factors affecting changes in Quercus faginea forests. The results of this research revealed substantial changes in the spatial patterns of Q. faginea forests in the Central Pre-Pyrenees over the last 50 years. These changes have been clearly reflected in noteworthy increase of fragmentation, isolation degrees, and patch irregularity. Changes in the spatial patterns of Q. faginea forests were particularly driven by the vast introduction of pine plantations and the former deforestation, associated with increasing the amount of croplands and pastures. In addition, roads acted as attractors for changes in land use and deforestation, which influenced strongly the spatial variability in Q. faginea forests. Therefore, the long-term sustainability of these forests largely depends on the landscape conservation, where this species occurs. Moreover, an improvement in the integrity and connectivity of the remaining patches of native Q. faginea forests is still demanded.     

Deforestation and fragmentation of Chaco dry forest in NW Argentina (1972–2007)

The sustained increase in the global food demand has favoured the recent expansion of industrial agriculture into neotropical dry forest ecosystems, with resulting changes in their extent and spatial configuration. Based on Landsat satellite images, we analyzed changes in forest cover and landscape configuration over an area of 600 by 100 km located in NW Argentina (Tucumán and Salta provinces) in four periods between 1972 and 2007. The study area, one of the most active deforestation frontiers of South American dry forest, was divided into six relatively homogeneous sectors in terms of land property structure and biophysical characteristics. During the study period 1.4 millions hectares of dry forest were cleared. Deforestation started in the 1970s as a result of technological changes and increasing rainfall; continued (with spatial and temporal fluctuations) during the 1980s and 1990s in association to the sustained global demand of soybean, and was accelerated (to ca. 100,000 ha year⁻¹) between 2001 and 2007 following the global increase in commodity prices, and the national peso devaluation. We described the landscape structure using eight landscape indices, summarized as one synthesis value: the Euclidian distance across the seven dimensions from a theoretical non-fragmented situation. In areas with soil limitations deforestation resulted in relatively stable, highly fragmented landscapes. In contrast, the sites with regional coarser-scale limitations (rainfall), deforestation produced a less fragmented landscape where agriculture concentrates in sites with high rainfall. Sites with no limitations for agriculture tend to a largely deforested landscape with few small and poorly connected forest patches. The land properties size seems to influence some indices of fragmentation, but the synthetic index of fragmentation suggests an overall convergence of fragmentation patterns towards a similar configuration across different biophysical and land tenure conditions.     

盈江县沙化土地的综合治理

山高坡陡，切割强烈；降水丰富，降水年内分配不均；土层深厚，土体疏松等是盈江县沙化土地形成的主要自然因素。森林植被遭到破坏，坡耕地面积逐年增加等是盈江县沙化土地形成的主要人为因素。盈江县现有沙化土地面积2520.5hm^2，有流动沙地、兰固定沙地、固定沙地、沙改田4个沙化土地类型。通过长期的治理，沙化土地各类型面积及利用状况发生明显变化，总体发展趋势呈现逆转，沙化土地得到有效利用。今后需以治理水土流失为中心，采取生物措施、工程措施、农业措施相结合，开发利用并举的综合治理措施。     

城郊采石场生态恢复与景观重建

打破对采石场传统的绿化模式,将采石场分成平台面和立体面,由于各个"面"的功能、结构、质地与特点存在明显的差异,针对不同"台""面"采取不同的工程措施和生物措施:将"平台区"设计为休闲园,利用坡面和挡土墙绿化,设计"藤龙景观",不但恢复生态环境,而且,营造了新的特色景观,不仅为停采的采石场提供就业机会,同时又为城区居民提供休闲度假去处。       

拉萨河谷植被演替规律及人工恢复对策

阐述拉萨河谷植被分布特征及演替规律,分析人为干扰对植被分布的影响。提出保护残存的天然植被,适度的造林技术,适当选择造林树种,采用容器育苗技术,开发替代能源,合理利用水资源等植被恢复对策。     

尼日利亚农林业发展与荒漠化防治探析

尼日利亚南部紧邻几内亚湾, 为热带雨林气候, 北部与撒哈拉沙漠接壤, 为稀树干草原。历史以来, 有多条沙垄深入该国北部100~200 km, 风沙土遍布, 生态环境脆弱。近年来, 森林因砍伐和烧荒以每年1.36%的速度消失, 而沙化土地每年以35万hm2的速度增加, 荒漠化发展迅速, 生态安全堪忧, 气候旱化、人口增加、沙质地表及农林牧资源过度开发利用为主因。尼日利亚通过采取减少木材依赖型能源与工业、控制人口、草畜平衡、禁止开垦、环境意识与法制结合等对策与措施, 提高土地生产力, 逐步恢复稀树干草原, 促进社会经济可持续发展和生态环境的良性循环。文中介绍了尼日利亚农林业发展现状、荒漠化与沙产业发展、荒漠化防治中存在的问题与对策, 认为长期开展气候周期性变化对生物多样性与荒漠化关系影响研究以及成功地采用林木引种驯化、育苗造林、流沙垄固定、防护林营造、沙产业开发、适地适树等技术值得我国学习与借鉴。     

Understorey vegetation in young naturally regenerated and planted birch (Betula spp.) stands on abandoned agricultural land

The abandonment of agricultural lands in Northern and Eastern Europe increases the area covered by first generation forests, which are either formed as an outcome of secondary succession or established as plantations. However, questions remain as to how these new stands develop and what kind of species they favour, which in turn has impacts on their ecological and economical value. Our aim was to compare understorey vascular plant and bryophyte vegetation characteristics between naturally regenerated and planted birch stands on abandoned agricultural sites in Estonia, focusing on the aspects of species richness and forest understorey recovery. Species richness and diversity of vascular plants were similar in both stand types but the number of forest vascular plant species was significantly higher in naturally regenerated stands. The bryophyte layer of naturally regenerated stands had a higher species richness, diversity, and number of forest bryophyte species. The higher number of forest vascular plant and bryophyte species in naturally regenerated stands can be explained by the longer undisturbed succession period. The recovery of the forest understorey was unaffected by former agricultural land use (crop field or grassland). The influence of soil properties on the recovery of the forest understorey was not detected, but the number of vascular plant species that grow in forests as well as in grasslands was negatively correlated with distance from forest. Overall, understorey vegetation of natural and planted birch stands did not reveal substantial differences. However, in the case of vigorous natural birch regeneration in the vicinity of forest land, unassisted reforestation should be favoured.     

基于GIS的桃山林场森林景观格局研究

以河北省木兰围场国有林场管理局桃山林场施业区内的森林资源为对象,利用GIS技术对其森林景观及分布规律进行分析,结果表明:桃山林场森林景观以混交林为主体,其面积占景观总面积的60.42%,斑块数量占景观斑块总数量的29.01%,优势度达到3.474 5。在斑块规模中,以混交林斑块最大,纯林和荒山荒地也有较大规模,疏林地也有相当规模分布,未成林造林地、宜林沙荒地、灌木林、耕地和其它用地景观规模最小;各类斑块的极差值均较大,斑块大小的分化较强烈。混交林的形状最复杂;其次是未成林造林地、纯林、荒山荒地、灌木林、宜林沙荒地、耕地和疏林地;其它用地的形状规整,边缘形状简单,说明这类景观斑块受人为干较严重。     

Effects of roads,topography, and land use on forest cover dynamics in the Brazilian Atlantic Forest

Roads and topography can determine patterns of land use and distribution of forest cover, particularly in tropical regions. We evaluated how road density, land use, and topography affected forest fragmentation, deforestation and forest regrowth in a Brazilian Atlantic Forest region near the city of São Paulo. We mapped roads and land use/land cover for three years (1962, 1981 and 2000) from historical aerial photographs, and summarized the distribution of roads, land use/land cover and topography within a grid of 94 non-overlapping 100 ha squares. We used generalized least squares regression models for data analysis. Our models showed that forest fragmentation and deforestation depended on topography, land use and road density, whereas forest regrowth depended primarily on land use. However, the relationships between these variables and forest dynamics changed in the two studied periods; land use and slope were the strongest predictors from 1962 to 1981, and past (1962) road density and land use were the strongest predictors for the following period (1981–2000). Roads had the strongest relationship with deforestation and forest fragmentation when the expansions of agriculture and buildings were limited to already deforested areas, and when there was a rapid expansion of development, under influence of São Paulo city. Furthermore, the past (1962) road network was more important than the recent road network (1981) when explaining forest dynamics between 1981 and 2000, suggesting a long-term effect of roads. Roads are permanent scars on the landscape and facilitate deforestation and forest fragmentation due to increased accessibility and land valorization, which control land-use and land-cover dynamics. Topography directly affected deforestation, agriculture and road expansion, mainly between 1962 and 1981. Forest are thus in peril where there are more roads, and long-term conservation strategies should consider ways to mitigate roads as permanent landscape features and drivers facilitators of deforestation and forest fragmentation.     

基于适宜性评价的深圳梅林云步道选线研究

以深圳梅林山云步道为例,探索高密度城市中心区的浅山山地风景游步道的选线研究及建设策略。采用层次分析和开发适宜性评价方法,从空间、生态、行为3个层面,选取了地形地貌、植被、用地阻隔、交通、建设5个因子,建立综合评价体系,生成了梅林山云步道开发适宜性的分级图,结合梅林片区的用地规划、相关保护规划、城市空间格局与以及景观人文资源等现状,将云步道线路与区域、市域绿道系统和周边绿地等对接,在高密度的城市结构中创造展示自然生态法则的山地风景道系统与城市眺望系统。     

Linking physical, economic and institutional constraints of land use change and forest conservation in the hills of Nepal

This paper analyses the changes in spatial patterns of agricultural land use during the period 1976–2000 along the altitudinal gradients in a watershed in Nepal. Land change patterns during this period were examined using information on land use derived from satellite images from 1976, 1990 and 2000. During the 24-year period from 1976 to 2000 agricultural land use increased by 35% at a cost of loss of forestland. Agricultural expansion was most conspicuous at higher elevations (1150–2000-m). About 36%, 18% and 6% of forestland was converted into agricultural activities from higher, middle and lower elevations respectively in the period from 1990 to 2000. Spatial distribution of living standard parameters, including farm family income and, food availability obtained from family surveys, shows a decreasing trend as the elevation increases whereas percentage of food bought shows an increasing trend. In this way it was found that, lost forest areas were smaller when located around high-income areas with good quality agricultural land and near an administrative centre as compared to areas located around low-income areas with low quality agricultural land and far from an administrative centre. Additionally, a regression model is constructed, to link the socioeconomic variables with the conversion of forestland into agricultural activities, breaking the study area into smaller zones. The spatial trajectories of these zones are then contrasted, paying particular attention to the socioeconomic conditions and institutional arrangements governing access to land resources. The study finds that while overall land change patterns in the region are largely explained by elevation and the socioeconomic conditions of people living adjacent to the forestland, more specifically, in sub-regional areas, trajectories reflect the signatures of institutions governing access to land. As sustainability of the watershed is dependent on forests, continued depletion of forest resources will result in poor economic returns from agriculture for local people together with loss of ecosystem services.