Practical Application of Multivariant Analysis Techniques to the Forest Management of Active Farmers in the Northwest of Spain

As managers almost exclusive in many worldwide forestry regions, non-industrial private forest (NIPF) owners come to play a key role in balanced integrating the variety of forest uses and functions in policies for promoting and revitalising rural areas. In Galicia, a region in the Spanish Northwest, over 67.5% of forestland and 80% of woodland is managed by NIPF owners. Almost 40% of the Galician NIPF owners are agricultural or livestock farmers who manage a total of 169,755 agrarian holdings with woodlands. Although the number of agricultural holdings has dropped significantly over the last 60?years, farmers still constitute a representative section of the NIPF owner population in Galicia. Starting from an initial population of 31,285 active full-time professional farmers in the region, and based on data collected by a personal questionnaire from a sample comprising 4,383 of these professional farmers for the period 1993?C2003, Discriminant Analysis (DA) was used to identify which socioeconomic, territorial and public-political factors were useful in distinguishing, and to what extent, that a certain population of Galician active farmers should opt to own and manage forestland areas within their agrarian holdings. The results suggested that the forestry production capacity for the area in which the agricultural holding is located, the size and the number of plots in the land base, the number of years the farmer has been the owner and the economic yield from the holding over the total family income were key factors in distinguishing between farmers with forestry activity (forestland owners) and farmers with no forestry activity (farmland owners). These findings could be used as a guide for designing, planning, and implementing research and policy measures that could allow NIPF landowners with farming and livestock activity to develop sustainable forestry, as key agents in promoting rural development.     

Effects of changes in land use and land cover on sediment discharge of runoff in a typical watershed in the hill and gully loess region of northwest China

Land use plays a much more important role than other factors, such as climate, soil properties, topographic features, vegetation coverage, human activities and others, in affecting soil erosion and sediment discharge. In order to understand the effects of changes in land use on sediment discharge and to provide a theoretical basis for land use planning, management and ecological restoration, we used the controlled Qiaozidong watershed and the uncontrolled Qiaozixi watershed in the third sub-region of the Loess Plateau as examples and analyzed the effects of land use and land cover on the discharge of sediments. The results show that the impact of land use and land cover on the annual amount of sediment discharge is significant. Compared with the uncontrolled watershed during similar periods, the amount of sediment discharged from the controlled watershed was reduced by 44%, 75% and 86%, respectively, in wet, normal and dry years. In the controlled watershed, compared with the period from 1986 to 1994, the amount of sediments discharged was less during the period from 1995 to 2004. The impact of land use and land cover on sediment discharge demonstrated characteristics of seasonal fluctuation. The effects of sediment reduction in the controlled watershed were greater than those in the uncontrolled watershed in May and September. In the controlled watershed, the reduction effect coincided with the distribution of rainfall. The amount of discharged flood sediments is closely correlated with rainfall, rainfall intensity in a 60 min period and the volume of flood. The rainstorm-runoff process and the rainstorm-sediment discharge process demonstrate that land cover has a strong regulatory and control function in the flood process and sediment discharge in rainstorms. For the controlled watershed, given the same precipitation frequency distribution, the average amount of sediment discharged during the land use period from 1995 to 2004 was less than that during the earlier land use period from 1986 to 1994 under every recurrent period. __________ Translated from Journal of Beijing Forestry University, 2007, 29(6): 115–122 [译自: 北京林业大学学报]     

对当前征占用林地管理主要问题之反思

根据全国连清资料,我国每年有林地转变为非林地的面积为56.2万hm2,目前我国林地管理存在着管理部门之间关系混乱、行政干预严重、林业部门自身执法犯法问题突出等问题。分析了造成这些问题的原因,提出了建立健全法制、理顺管理关系、加大案件查处力度、加强执法队伍建设、加大舆论宣传等对策。     

鄂托克旗土地利用动态变化及其影响要素分析

在RS与GIS技术的支持下,利用1991、2000和2007年三期TM影像,对鄂托克旗1991-2007年的土地利用动态变化特征及其影响要素进行分析。结果表明,土地利用最重要的转化方向有：1991-2000年耕地向草地、未利用地和城乡、工矿用地的转化;草地、水域向未利用地的转化;2000-2007年未利用地向草地、水域和耕地的转化;耕地向林地和草地的转化;城乡、工矿居民点用地向草地和林地的转化。反映鄂托克旗既有退耕还林还草、积极治理沙漠的事实,又有毁草开垦荒地的现实。随着耕地和未利用土地的减少,林地和草地面积增加,说明当地环境的改善已取得了成效。     

Modeling landscape dynamics in an Atlantic Rainforest region: Implications for conservation

The dynamics of the Atlantic Rainforest loss and recovery are still not fully understood despite its long history of human occupation. In this study, we investigated changes in an Atlantic Rainforest region due to major biophysical and human proximate causes. First, we modeled land-cover and land-use changes from 1962 to 2000, including deforestation and forest regrowth, and thereby simulated future landscape trajectories to assess their possible effects on the conservation of forest species of the Ibiúna Plateau, a region located in Southeastern Brazil within the Atlantic Rainforest biome. We modeled four scenarios (status quo, random, lawenforcement, and land-use intensification) and simulated their resulting landscape trajectories for the year 2019 using DINAMICA. The landscape dynamics in the study region were particularly intense. During the first period of 1962–1981, the rate of forest regrowth (3% year⁻¹) was greater than the rate of deforestation (2% year⁻¹), whereas in the latter period of 1981–2000, increasing urbanization and the spreading of rural establishments resulted in more deforestation (2.9% year⁻¹) than regrowth (1% year⁻¹). These dynamics imprinted a heterogeneous landscape, leading to the predominance of progressively younger secondary forests with increasingly less capacity of hosting sensitive forest species. The influence of proximate causes on the dynamics of deforestation and forest regrowth showed consistent patterns, such as higher forest regrowth rates near rivers, on steep slopes and far from dirt roads, whereas losses in young secondary vegetation and forest were far from rivers, on gentle slopes and near urban areas. Of the modeled scenarios, only the law enforcement scenario may lead to the recovery of a network of interconnected forest patches, suggesting that simply the enforcement of current forest laws, which prohibit deforestation on unsuitable agricultural areas and along river margins and establish a minimum of 20% of forest remnant per rural property, may effectively favor forest species conservation in the short term (two decades) without the need of any forest restoration effort.     

Fragmentation patterns and systematic transitions of the forested landscape in the upper Amazon region,Ecuador 1990–2008

The analysis of the systematic transitions in the forested landscape and the study of the forest fragmentation patterns allow us to deepen our understanding of the changes in the vegetation ground cover. The importance of knowing the intricate patterns of the land usage of the upper basin of the Amazon region is widely recognized. This zone is one of the most diverse biological areas in the world, is home to large areas of mature tropical cloud forest and demonstrates high probabilities of stable climatic conditions in light of global warming. The research quan- tiffed systematic transitions through the ＂loss＂ and ＂gain＂ of the different categories of landscape during the eighteen-year study period of the Ecuadorian Amazon Region （EAR）, the forest fragmentation patterns were also analyzed based on a set of indicators. Therefore, with respect to the entirety of the landscape, the results registered for the ground coverage in forested areas during the first period （1990-2000）, show a decrease of 6.99% and an increase of 0.68%; and during the second period （2000-2008）, show a decrease of 3.99% and an increase of 2.14%. It demonstrated that forest and agricultural areas tended to replace or be replaced by herbaceous vegetation faster than expected fortuitously. Finally, the indices of fragmentation signaled intense changes during the 1990-2000 period with a reduction during the period 2000-2008. Per- centages registered in the Largest Patch Index （LPI） were between 79.58%; 52.39% and 49.99% respectively; while the Patch Density （PD） varied between 0.04; 0.06 and 0.07. This suggests the propensity of for- est cover to remain intact. The results of this investigation suggest a tendency towards stability in Ecuador＇s Amazon landscape. Within the framework for development and management of this area, the tendency is natural regeneration. This permits a consolidation of the conservation, reforestation, forestation and agricultural forestry plans, programs and systems for the protected areas in EAR.     

我国喀斯特石漠化地区林下经济种植模式及问题分析

由于我国喀斯特石漠化地区人地矛盾突出、林地与土地利用率低、森林生态系统破坏严重,改善喀斯特地区森林生态系统的经济功能、防控石漠化恶性演替仍是当下亟需解决的艰巨任务。林下种植是一种经典的立体复合林业生产经营方式,能够实现林地资源最大利用化、缓解人多地少的矛盾、推动区域经济循环可持续发展、保障林农经济效益稳步增长,最终达到林业经济、农业发展和生态建设同步优化的目标。文中主要分析了喀斯特石漠化地区8种代表性林下种植模式的特征、效益及不足,并提出各林下种植模式关于结构优化升级、调整改善方面的核心对策,以期为喀斯特地区石漠化治理与林业发展提供理论支持与借鉴,确保生态、经济、社会效益的同步优化。     

Monitoring the effects of land use and cover changes on net primary production: A case study in China's Yongding River basin

Changing land uses and cover types influence vegetation composition and health, so understanding the effects of these changes on net primary production (NPP) provides an important tool for monitoring ecosystem responses to environmental change. Using remote-sensing images and precipitation, temperature, and total solar radiation data from 1978, 1987, 2000, and 2005, and a light utilization efficiency model, we studied the effects of changes in these parameters and land use and cover types on NPP in China's Yongding River basin. We determined the NDVI of vegetation in the basin, and used these results to estimate the NPP of vegetation in the basin and the influence of land use and cover type changes on NPP under two climate scenarios: one in which the precipitation and temperature of the previous period remain unchanged into the following period, that is, use the climate in 1978, 1987 and 2000 to analyze NPP data in 1987, 2000 and 2005 respectively, and another in which both parameters remain constant at their 1978 values throughout the study period. With the climate unchanged from the former period, NPP in 1987 decreased compared with the 1978 value by 20–50 gC/m², and then increased by more than 40 gC/m² in western and central parts of the basin from 1987 to 2000. From 2000 to 2005, NPP decreased in the northwestern, northern, and eastern parts of the basin. With climate unchanged from 1978 to 2005, NPP increased from 1987 to 2000 by from 10 to 30 gC/m² in most areas. From 2000 to 2005, some farmland in western and northwestern parts of the basin and some forest land were converted into grassland, decreasing NPP by 40–50 gC/m².     

湖南省林地保护利用现状及对策

通过对湖南省林地保护利用现状进行分析,探讨了存在的主要问题,从严格林地用途管制、实行林地分级保护、加强森林资源管理、积极补充林地、引导节约用地、优化结构、保障重点、科学经营、持续利用等方面提出了相应的对策。     

Impact of Land Tenure Change on Land Use

China is a public ownership country. At present, theownership of land belongs to the country andcollectivity. In China, the meaning of ownership ofland is the light that the owners of land can possessthe land, use the land, get some interest from the landand deal with the land according to laws. The 4 sectionsof ownership of land can either be combined or beseparated to carry out. In practice, these 4 sections ofownership are usually separated to carry out. The tenureof land is an independent…     

农林牧交错典型区近20年的林地变化及其驱动因素分析——以阿鲁科尔沁旗为例

选择农牧交错典型区－阿鲁科尔沁旗,利用1980年以来的各典型时期的土地详查数据和遥感影像数据,运用时间序列分析与比较方法、LUCC指数分析方法,对其近20年的林地变化过程进行分析,结果发现:1985-2008年间,研究区林地面积增加11.295万hm2,林地动态度达2.32,林地已成为该旗仅次于草地的土地利用重要类型;...     

Soil and sediment phosphorus fractions in a forested watershed at Acadia National Park,ME, USA

Phosphorus (P) is often the critical limiting nutrient controlling the productivity of natural waters. Understanding the linkages between terrestrial and aquatic P dynamics is essential to defining the mechanisms governing P availability in the ecosystem. We used P fractionation techniques to investigate landscape patterns of P distribution in soils, and associated stream and lake sediments, in a forested watershed at Acadia National Park, ME, USA. Specifically, we investigated the chemical and spatial distribution of P in primary and secondary mineral phases along a topographic and bathymetric transect based on distance from the stream for soils and lake sediments. The dominant P fraction was associated with aluminum (Al) hydroxides, a fraction that also included some iron (Fe) hydroxides and organic P. The Al–P fraction accounted for 62% and 66% of total P in all soil and lake samples, respectively. These results suggest that secondary Al, and to a lesser extent Fe, dominate P dynamics in these soils and lakes. Stream sediments appear to originate from deeper, less weathered portions of the soil with lower accumulations of secondary Al and Fe. As a result, stream sediments have little capacity for adsorbing P, relative to soil or lake sediments. Phosphorus fractionation results also suggested that both exposed and occluded primary apatite-P still persists in these soils, stream sediments, and lake sediments. Extractable apatite-P concentrations increased progressively with decreasing distance from the stream in the watershed and with increasing distance from the stream and depth in the lake. These trends were attributed to spatial patterns in the intensity of pedogenesis in the watershed and the influence of winnowing and sedimentation on lake sediment composition.     

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.     

上思县林地各功能分区的保护利用方向与措施

根据区域资源现状以及生态建设和林业产业布局,将上思县林地划分为5个功能区,即北部四方岭用材林功能区、中部台地工业原料林功能区、东部水源涵养林功能区、南部丘陵防护林用材林功能区、南部十万大山自然保护功能区。阐述各功能分区范围和林地资源现状,并参照国家有关林地保护利用的相关规划要求,分别不同功能分区提出相应的保护利用方向和措施。     

Assessing rates of forest change and fragmentation in Alabama,USA, using the vegetation change tracker model

Forest change is of great concern for land use decision makers and conservation communities. Quantitative and spatial forest change information is critical for addressing many pressing issues, including global climate change, carbon budgets, and sustainability. In this study, our analysis focuses on the differences in geospatial patterns and their changes between federal forests and nonfederal forests in Alabama over the time period 1987–2005, by interpreting 163 Landsat Thematic Mapper (TM) scenes using a vegetation change tracker (VCT) model. Our analysis revealed that for the most part of 1990 s and between 2000 and 2005, Alabama lost about 2% of its forest on an annual basis due to disturbances, but much of the losses were balanced by forest regeneration from previous disturbances. The disturbance maps revealed that federal forests were reasonably well protected, with the fragmentation remaining relatively stable over time. In contrast, nonfederal forests, which are predominant in area share (about 95%), were heavily disturbed, clearly demonstrating decreasing levels of fragmentation during the time period 1987–1993 giving way to a subsequent accelerating fragmentation during the time period 1994–2005. Additionally, the identification of the statistical relationships between forest fragmentation status and forest loss rate and forest net change rate in relation to land ownership implied the distinct differences in forest cutting rate and cutting patterns between federal forests and nonfederal forests. The forest spatial change information derived from the model has provided valuable insights regarding regional forest management practices and disturbance regimes, which are closely associated with regional economics and environmental concerns.     

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。     

半干旱黄土丘陵沟壑区人工林土壤水分与其群落特征研究

2009年,对定西巉口林场人工针叶林、阔叶林及针阔混交林23个植被类型土壤水分和林下物种多样性特征进行了连续观测和调查.结果显示:山杏林地土壤水分最低,青杨林和青杨+油松混交林地最高,均与其他林地存在显著性差异,荒草地土壤水分高于其他林地介于中间;土壤水分亏缺量最大的为阔叶乔木或灌木林,其次为针叶林或针阔混交林,衰退的人工林地土壤水分亏缺量最小;浅层土壤水分(0～80 mm)与Margalef丰富度指数、Shannon-wiener多样性指数和均匀度指数相关性极显著,存在线性关系.而深层土壤水分与上面3个植物多样性指数无相关性.该研究对阐明人工林地土壤水分环境以及其与群落发育阶段和植物多样的相应关系,指导科学培育人工林提供理论基础.     

国内外林地流转影响因素及成效研究进展

文中对比国内外不同产权安排下林地流转影响因素及成效的研究内容与方法发现,由于林地产权制度和交易规模、交易主体的不同,对私有林地交易和集体林地流转的研究存在差异性.工业林地交易行为的研究基于企业利润最大化的角度;家庭林地的出售受财产税等林地持有成本的影响较大,林地购入以休闲、娱乐等效用最大化为目标.我国集体林区小农户行为...     

Concentrated flow paths in riparian buffer zones of southern Illinois

Riparian buffers in agricultural landscapes should be designed to trap pollutants in overland flow by slowing, filtering, and infiltrating surface runoff entering the buffer via sheet flow. However, observational evidence suggests that concentrated flow is prevalent from agricultural fields. Over time sediment can accumulate in riparian buffers forming berms that restrict sheet flow; these berms ultimately back up surface runoff, resulting in an eventual breakthrough that concentrates overland flow. This study examines the occurrence of concentrated flow paths (CFPs) in riparian buffers at both the field and watershed scale. At the field scale, intensive topographic surveys were conducted at ten field sites in southern Illinois. To assess the prevalence of CFPs at the watershed scale, three watersheds in southern Illinois were selected for walking stream surveys along randomly selected 1,000 m reaches. CFPs were identified in all topographic surveys and all walking stream surveys. Among field sites, concentrated flow accounted for 82.5–100% of the drainage leaving the agricultural fields. Sediment berm accumulation was identified at all field sites and was positively correlated with CFP size. At the watershed scale, CFPs were more abundant in agricultural areas compared to forested land. Results from this study indicate that concentrated flow was prevalent across all study sites at both the field and watershed scale. Thus, surface water quality may suffer in areas with poorly functioning buffers, and managers must consider the occurrence of CFPs when designing and maintaining riparian buffers to protect stream water quality.     

海口市土地利用景观稳定性研究

基于克里金插值模型对海口市土地利用景观格局稳定性进行研究分析,利用改进型土地利用景观稳定性评价模型对景观稳定性综合评价,得出：（1）2010—2015 年,海口市生态环境整体良好,各行政区景观稳定性差异显著,但整体呈下降趋势;各行政区景观均遭受不同程度破坏,景观稳定性遭受影响;（2）2010—2015 年,海口市城镇建设不断扩张及国际旅游岛战略不断推进,景观稳定性整体呈现下降趋势,Ⅴ及景观稳定区消失,Ⅰ级景观稳定区和Ⅱ级景观稳定区面积大幅增加。