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Exploring the Forest Cover Changes and Influential Factors of Dongsithouane National Production Forest Area, Savannakhet Province, Lao PDR
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作者 Souvanthone Douangphachachanh Chittana Phompila +5 位作者 Dipjoy Chakma Inta Chanthavong Maliphone Douangphachanh Puvadol Doydee Pengxiang Zhao Yuanchun Yu 《Journal of Data Analysis and Information Processing》 2024年第3期432-461,共30页
The Dongsithouane National Production Forest (DNPF) is one of the largest natural forest areas in Savannakhet, Lao PDR, which has been a vital support for the local community’s livelihood, Recently, significant chang... The Dongsithouane National Production Forest (DNPF) is one of the largest natural forest areas in Savannakhet, Lao PDR, which has been a vital support for the local community’s livelihood, Recently, significant changes in land use and land cover (LULC) have been observed in this area, leading to a reduction of natural forests. There were two separate methods of this study: firstly, to identify LULC changes across three different periods, spectral imagery from the Landsat 5 Thematic Mapper (TM) for the years 2001 and 2011, and the Landsat 8 Operational Land Imager (OLI) for 2021 were used as the primary data sources. The satellite images were preprocessed for various forest classes, including pretreatment of the top of atmosphere reflectance by using QGIS software’s semi-automatic classification plug-in (SCP), and ArcGIS was used for post-classification. A supervised classification approach was applied to the satellite images from 2001, 2011, and 2021 to generate diverse maps of LULC. Secondly, a household survey dataset was used to investigate influential factors. Approximately 220 households were interviewed in order to collect socio-economic information (including data on population growth, increased business activities, location of the area, agriculture land expansion, and need for settlement land). Household survey data was analyzed by using SPSS. Descriptive statistics, including frequency distributions and percentages, were applied to observe characteristics. Additionally, a binary logistic regression model was used to analyze the socioeconomic factors related to LULC change in DNPF. Key findings indicated a decline in natural forest areas within the study site. Specifically, both dry dipterocarp forest (−11.35%) and mixed deciduous forest (−0.18%) decreased from 2001 to 2021. The overall accuracy of the LULC maps was 94%, 86%, and 89% for the years 2001, 2011, and 2021 respectively. In contrast, agricultural land increased significantly by 155.70%, while built-up land, and water bodies increased by 65.54% and 35.33%, respectively. The results also highlighted a significant increase in construction land, up to 65.54%. Furthermore, the study found a correlation between agricultural expansion and a reduction of forest areas, along with an increase in built-up land along the forest areas’ boundaries. Timber exploitation and charcoal production also contributed to the decline in forest cover. The logistic regression model identified significant determinants of LULC change, including the area’s location, agricultural land expansion, increased business activity, and the need for settlement land. These factors have influenced the management of DNPF. Urgent sustainable management practices and actions, including forest ecosystem protection, village agricultural zoning, water source and watershed protection and public awareness, are required to preserve the forest areas of DNPF. 展开更多
关键词 Land Use/Land cover Change QGIS SCP Socioeconomic Factor Dongsithouane National Production forest Lao PDR
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Estimating Tree Canopy Cover and Identifying Deforestation Patterns in Meghalaya (1990-2021) through ML Classifiers
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作者 Tapan Dhar Sengalvarayan Aravindan Basudeb Bhatta 《Journal of Geographic Information System》 2023年第3期309-333,共25页
This study utilizes ML classifiers to estimate canopy density based on three decades of data (1990-2021). The Support Vector Machine (SVM) classifier outperformed other classifiers, such as Random Tree and Maximum Lik... This study utilizes ML classifiers to estimate canopy density based on three decades of data (1990-2021). The Support Vector Machine (SVM) classifier outperformed other classifiers, such as Random Tree and Maximum Likelihood. Satellite data from Landsat and Sentinel 2 was classified using a developed python model, providing an economical and time-saving approach. The accuracy of the classification was evaluated through a confusion matrix and area computation. The findings indicate a negative trend in the overall decadal change, with significant tree loss attributed to jhum cultivation, mining, and quarry activities. However, positive changes were observed in recent years due to the ban on illegal mining. The study highlights the dynamic nature of tree cover and emphasizes the need for biennial assessments using at least five time-series data. Micro-level analysis in Shallang, West Khasi hills, revealed a concerning trend of shortening jhum cycles. Automation in canopy change analysis is crucial for effective forest monitoring, providing timely information for law enforcement proposals and involving forest managers, stakeholders, and watchdog organizations. 展开更多
关键词 MEGHALAYA forest cover ML SVM Python Script Decadal Change Biennial Change
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Anthropogenic Threats to Degraded Forest Land in the Savannahs’ Region of Togo from 1984 to 2020, West Africa
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作者 Kossi Senyo Ehlui Wouyo Atakpama +6 位作者 Henrik von Wehrden Alagie Bah Edinam Kola Christian Anthony-Krueger Hodabalo Egbelou Kokouvi Bruno Kokou Tchaa Boukpessi 《Journal of Geoscience and Environment Protection》 2024年第1期164-179,共16页
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... 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. 展开更多
关键词 forest Degradation Land Use Land cover Savannahs Region TOGO
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Analysis of PM2.5 concentrations in Heilongjiang Province associated with forest cover and other factors 被引量:6
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作者 Yu Zheng San Li +2 位作者 Chuanshan Zou Xiaojian Ma Guocai Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第1期269-276,共8页
Atmospheric particulate matter(PM2.5) seriously influences air quality. It is considered one of the main environmental triggers for lung and heart diseases. Air pollutants can be adsorbed by forest. In this study we i... Atmospheric particulate matter(PM2.5) seriously influences air quality. It is considered one of the main environmental triggers for lung and heart diseases. Air pollutants can be adsorbed by forest. In this study we investigated the effect of forest cover on urban PM2.5 concentrations in 12 cities in Heilongjiang Province,China. The forest cover in each city was constant throughout the study period. The average daily concentration of PM2.5 in 12 cities was below 75 lg/m^3 during the non-heating period but exceeded this level during heating period. Furthermore, there were more moderate pollution days in six cities. This indicated that forests had the ability to reduce the concentration of PM2.5 but the main cause of air pollution was excessive human interference and artificial heating in winter. We classified the 12 cities according to the average PM2.5 concentrations. The relationship between PM2.5 concentrations and forest cover was obtained by integrating forest cover, land area,heated areas and number of vehicles in cities. Finally,considering the complexity of PM2.5 formation and based on the theory of random forestry, we selected six cities and analyzed their meteorological and air pollutant data. The main factors affecting PM2.5 concentrations were PM10,NO_2, CO and SO_2 in air pollutants while meteorological factors were secondary. 展开更多
关键词 forest cover Heilongjiang PROVINCE Influencing factor PM2.5 CONCENTRATIONS RANDOM forest
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Forest Cover Change Assessment in Conflict-affected Areas of Northwest Pakistan: the Case of Swat and Shangla Districts 被引量:4
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作者 Faisal Mueen QAMER Sawaid ABBAS +3 位作者 Rashid SALEEM Khurram SHEHZAD Hassan ALI Hammad GILANI 《Journal of Mountain Science》 SCIE CSCD 2012年第3期297-306,共10页
This study examines the spatial and temporal forest cover changes in Swat and Shangla districts to understand the deforestation pattern in context of the recent security conflict in these districts. We used multi-reso... This study examines the spatial and temporal forest cover changes in Swat and Shangla districts to understand the deforestation pattern in context of the recent security conflict in these districts. We used multi-resolution satellite images to assess the long term deforestation from 2001 to 2009 and also to identify episodic forest cutting areas appeared during the conflict period of Oct. 2007 - Oct. 2008. There are only 58 ha of deforestation identified during the conflict period while 1268 ha of gross annual deforestation were assessed during last eight years. Most of the deforestation patches persist around the administrative boundaries at sub-district levels (tehsils) which can be attributed to ambiguity in unclear jurisdiction between the forest official. The results highlight that the forest cutting appeared in Swat and Shangla during the conflict period is not as significant when compared with the long term deforestation pattern in the area. On the one side the results of the study are supportive to the picture that emerges from international studies which report high rate of deforestation in the country and on the other side it negates any relation between the security situation and the increasing deforestation in the north western Pakistan. The study concludes that deforestation assessments require verification by independent sources of data, such as satellite imagery to improve our understanding of deforestation processes. 展开更多
关键词 forest cover change DEforestATION Conflict-affected area GIS Pakistan
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Analysis of forest cover change at Khadimnagar National Park, Sylhet,Bangladesh, using Landsat TM and GIS data 被引量:1
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作者 Mohammad Redowan Sharmin Akter Nusrat Islam 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第2期393-400,共8页
We mapped the forest cover of Khadimnagar National Park (KNP) of Sylhet Forest Division and estimated forest change over a period of 22 years (1988-2010) using Landsat TM images and other GIS data. Supervised clas... We mapped the forest cover of Khadimnagar National Park (KNP) of Sylhet Forest Division and estimated forest change over a period of 22 years (1988-2010) using Landsat TM images and other GIS data. Supervised classification and Normalized Difference Vegetation Index (NDVI) image classification approaches were applied to the images to produce three cover classes, viz. dense forest, medium dense forest, and bare land. The change map was produced by differencing classified imageries of 1988 and 2010 as before image and after image, respectively, in ERDAS IMAGINE. Error matrix and kappa statistics were used to assess the accuracy of the produced maps. Overall map accuracies resulting from supervised classification of 1988 and 2010 imageries were 84.6% (Kappa 0.75) and 87.5% (Kappa 0.80), respec- tively. Forest cover statistics resulting from supervised classification showed that dense forest and bare land declined from 526 ha (67%) to 417 ha (59%) and 105 ha (13%) to 8 ha (1%), respectively, whereas medium dense forest increased from 155 ha (20%) to 317 ha (40%). Forest cover change statistics derived from NDVI classification showed that dense forest declined from 525 ha (67%) to 421 ha (54%) while medium dense forest increased from 253 ha (32%) to 356 ha (45%). Both supervised and NDVI classification approaches showed similar trends of forest change, i.e. decrease of dense forest and increase of medium dense forest, which indicates dense forest has been converted to medium dense forest. Area of bare land was unchanged. Illicit felling, encroachment, and settlement near forests caused the dense forest decline while short and long rotation plantations raised in various years caused the increase in area of medium dense forest. Protective measures should be undertaken to check further degradation of forest at KNP. 展开更多
关键词 forest cover Landsat TM supervised classification NDVI change statistics error matrix
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Assessing impact of climate change on forest cover type shifts in Western Himalayan Eco-region 被引量:1
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作者 P.K.Joshi Asha Rawat +1 位作者 Sheena Narula Vinay Sinha 《Journal of Forestry Research》 CAS CSCD 2012年第1期75-80,共6页
Climate is a critical factor affecting forest ecosystems and their capacity to produce goods and services. Effects of climate change on forests depend on ecosystem-specific factors including dimensions of climate (te... Climate is a critical factor affecting forest ecosystems and their capacity to produce goods and services. Effects of climate change on forests depend on ecosystem-specific factors including dimensions of climate (temperature, precipitation, drought, wind etc.). Available infor- mation is not sufficient to support a quantitative assessment of the eco- logical, social and economic consequences. The present study assessed shifts in forest cover types of Western Himalayan Eco-region (700-4 500 m). 100 randomly selected samples (75 for training and 25 for testing the model), genetic algorithm of rule set parameters and climatic envelopes were used to assess the distribution of five prominent forest cover types (Temperate evergreen, Tropical semi-evergreen, Temperate conifer, Sub- tropical conifer, and Tropical moist deciduous forests). Modelling was conducted for four different scenarios, current scenario, changed precipi- tation (8% increase), changed temperature (1.07℃ increase), and both changed temperature and precipitation. On increasing precipitation a downward shift in the temperate evergreen and tropical semi-evergreen was observed, while sub-tropical conifer and tropical moist-deciduous forests showed a slight upward shift and temperate conifer showed 'no shift. On increasing temperatm'e, an upward shift in all forest types was observed except sub-tropical conifer forests without significant changes. When both temperature and precipitation were changed, the actual dis- tribution was maintained and slight upward shift was observed in all the forest types except sub-tropical conifer. It is important to understand the likely impacts of the projected climate change on the forest ecosystems, so that better management and conservation strategies can be adopted for the biodiversity and forest dependent community. Knowledge of impact mechanisms also enables identification and mitigation of some of the conditions that increase vulnerability to climate change in the forest sector. 展开更多
关键词 Climate change forest cover types SHIFT western Himalaya genetic algorithm
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Forest cover dynamics in Palas Valley Kohistan, Hindu Kush-Himalayan Mountains, Pakistan 被引量:1
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作者 Noor ul HAQ Fazlur RAHMAN +1 位作者 Iffat TABASSUM MEHRAN 《Journal of Mountain Science》 SCIE CSCD 2021年第2期416-426,共11页
Forest cover change in the mountainous region is driven by a variety of anthropogenic and natural factors.The Hindu Kush-Himalayan Mountains has experienced a considerable vegetation cover change due to intensive huma... Forest cover change in the mountainous region is driven by a variety of anthropogenic and natural factors.The Hindu Kush-Himalayan Mountains has experienced a considerable vegetation cover change due to intensive human activities,such as population growth,proximate causes,accessibility,unstable political situations,government policy failure and poverty.The present study seeks to find out the impact of population growth and road network expansion on forest cover of Palas valley based on remotely sensed data and employing geospatial techniques.Changes in forest cover were determined by classifying time-series satellite images of Landsat and Sentinel 2 A.The images of October 1980,2000,2010 and 2017 were classified into six land cover classes and then the impact of population growth and accessibility on forest cover was analyzed.Furthermore,forest cover and land-use change detection map was prepared using classified images of 1980 and 2017.The data were collected mainly from field visits(ground verification),census reports,Communication and Works Department,Kohistan.Satellite imageries were obtained from the United States Geological Survey’s websites and classified in ERDAS imagine 2014 and ESRI ArcGIS 10.2.1 using supervised classification-maximum likelihood algorithm.Result of this study revealed that a substantial reduction in forest cover has taken place mainly in the proximity of human settlements.On the average,during the study period,annually more than 460 hectares of forest area has been converted into other uses. 展开更多
关键词 forest cover changes Population growth Road networks DEforestATION Palas Valley Pakistan
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Forest cover change and its driving forces in Fagita Lekoma District,Ethiopia 被引量:1
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作者 Yigez Belayneh Guo Ru +2 位作者 Awoke Guadie Zebene Lakew Teffera Mengesha Tsega 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第5期1567-1582,共16页
This study investigated forest cover change and the driving forces behind it in Fagita Lekoma District of Ethiopia that resulted in increased forest cover,which might be uncommon outside this case study area.The LULC ... This study investigated forest cover change and the driving forces behind it in Fagita Lekoma District of Ethiopia that resulted in increased forest cover,which might be uncommon outside this case study area.The LULC change analysis was made from 2003 to 2017 based on Landsat images.Socioeconomic analysis was carried out to identify the major driving forces that resulted in LULC change.A questionnaire survey,focused group discussion,key informant interviews and field observation were employed to analyze the link between LULC change and the driving forces.The 15-year period(2003–2017)image analysis revealed that the coverage of forest lands,built-up areas and grassland has increased by 256%,100%and 96%,respectively,at the expense of cultivated lands and wetlands.The increased forest cover is due to the woodlots expansion of Acacia decurrens Willd,which are designed for sustainable livelihoods and a land revitalization strategy in the study area.Rapid population growth,an increasing demand for charcoal and subsequent market opportunities,preferred qualities of A.decurrens or black wattle to halt land degradation as well as to improve land productivity,have been identified as the major driving forces of forest cover change.Chi squared analysis revealed that:a comparative cash income from the sale of A.decurrens;a dependency on natural forests;the distance from the district administrative center;the size of the active labor force,and the area of land owned have significantly affected the cover change.The major forest cover change is due to the expansion of A.decurrens plantations that have socioeconomic and environmental implications to improve rural livelihoods and revitalize the land.Thus,the positive experiences identified in this study should be scaled-up and applied in other similar settings. 展开更多
关键词 Acacia decurrens forest cover change Land degradation REVITALIZATION Sustainable livelihoods
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Spatial assessment of forest cover and land-use changes in the Hindu-Kush mountain ranges of northern Pakistan 被引量:5
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作者 Sami ULLAH Muhammad FAROOQ +3 位作者 Muhammad SHAFIQUE Muhammad Afra SIYAB Fazli KAREEM Matthias DEES 《Journal of Mountain Science》 SCIE CSCD 2016年第7期1229-1237,共9页
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 ... 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. 展开更多
关键词 forest cover changes Land use changes Remote sensing Hindu-Kush Mountain regions SPOT satellite images
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Vegetation cover density and disturbance affected arbuscular mycorrhiza fungi spore density and root colonization in a dry Afromontane forest, northern Ethiopia 被引量:4
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作者 Emiru Birhane Nakiguli Fatumah +2 位作者 Kidane Gidey Amanuel Zenebe Ssemwanga Mohammed 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第3期671-682,共12页
Arbuscular mycorrhiza fungi(AMF) are vital in the regeneration of vegetation in disturbed ecosystems due to their numerous ecological advantages and therefore are good indicators of soil and ecosystem health at large.... Arbuscular mycorrhiza fungi(AMF) are vital in the regeneration of vegetation in disturbed ecosystems due to their numerous ecological advantages and therefore are good indicators of soil and ecosystem health at large. This study was aimed at determining how the seasonal, vegetation cover density, edaphic and anthropogenic factors affect AMF root colonization(RC) and spore density(SD)in Desa’a dry Afromontane forest. AMF RC and SD in the rhizosphere of five dominant woody species, Juniperus procera, Olea europaea, Maytenus arbutifolia, Carissa spinarum and Dodonaea angustifolia growing in Desa’a forest were studied during the rainy and the dry seasons in three permanent study vegetation cover density plots(dense, medium, and poor). Each plot(160 x40 m2) has two management practices(fenced and unfenced plots) of area. A 100 g sample of rhizosphere soil from moisturefree composite soil was used to determine spore density.Spore density ranged from 50 to 4467 spores/100 g soil,and all species were colonized by AMF within a range of 4–95%. Glomus was the dominant genus in the rhizosphere of all species. Vegetation cover density strongly affected SD and RC. The SD was significantly higher(p < 0.05) in the poor vegetation cover density than in the other two and lowest in the dense cover; root colonization showed the reverse trend. Management practices significantly(p <0.05) influenced AMF SD and RC, with the fenced plots being more favoured. Seasons significantly(p < 0.05) affected RC and SD. More RC and SD were observed in the wet period than the dry period. Correlating AMF SD and RC with soil physical and chemical properties showed no significant difference(p> 0.05) except for total nitrogen. Disturbance, vegetation cover density, season and total nitrogen are significant factors that control the dynamics and management interventions to maintain the forest health of dry Afromontane forests. 展开更多
关键词 AM fungi DISTURBANCE Dry Afromontane forest SEASON Vegetation cover density
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Homeward bound:canopy cover and species identity influence non-breeding season homing success and speed in forest birds 被引量:1
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作者 Jin Bai Chelsea A.Weitekamp +1 位作者 Kelly Frye Kathryn E.Sieving 《Avian Research》 CSCD 2021年第2期173-180,共8页
Background:Efficient and safe movement is fundamental for wild birds to thrive in their environments.For arboreal forest animals,especially birds,canopy cover has a large impact on birds’daily movements and is a cruc... Background:Efficient and safe movement is fundamental for wild birds to thrive in their environments.For arboreal forest animals,especially birds,canopy cover has a large impact on birds’daily movements and is a crucial component of conservation strategies seeking to retain avian population in disturbed or urban habitats.Methods:We translocated woodland bird species utilizing different forest strata during two non-breeding seasons in Gainesville,FL,USA.We used linear model and generalized linear model to examine the effects of canopy cover and species identity on homing success and speed.Results:Among our study species of Tufted Titmouse(Baeolophus bicolor),Carolina Chickadee(Poecile carolinensis),and Northern Cardinal(Cardinalis cardinalis),we found that Carolina Chickadees and Tufted Titmice were more likely to return than Northern Cardinals.Among birds that successfully returned,homing speed is significantly affected by forest canopy cover and species identity(titmice had higher homing speed than cardinals).Birds return much faster in landscape with higher canopy cover.Conclusions:This study presented evidence of species identity’s effect on homing success and speed in common feeder bird species in Southeast US and provided further evidence that bird movements in the suburban land cover are constrained by low canopy cover. 展开更多
关键词 forest bird movement forest canopy cover Homing behaviour Non-breeding season Site fidelity
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Application of Remote Sensing and GIS in Forest Cover Change in Tehsil Barawal, District Dir, Pakistan 被引量:1
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作者 Anwar Sajjad Ahmad Hussain +4 位作者 Umar Wahab Syed Adnan Saqib Ali Zahoor Ahmad Ashfaq Ali 《American Journal of Plant Sciences》 2015年第9期1501-1508,共8页
The forests of Pakistan replicate plentiful climatic, physiographic and edaphic differences in the country and these forests face a serious problem of deforestation. Geographic information system (GIS) techniques and ... The forests of Pakistan replicate plentiful climatic, physiographic and edaphic differences in the country and these forests face a serious problem of deforestation. Geographic information system (GIS) techniques and remote sensing (RS) from satellite platforms offer a best way to identify those areas of deforestation, and thus a GIS and RS based study was conducted in tehsil Barawal, district Dir (U) to analyze forest cover change. The main objectives of the study were to: 1) identify different classes of land use and land cover, and its spatial distribution in the study area;2) determine the trend, nature, location and magnitude of forest cover change;and 3) prepare maps of forest-cover change in different time periods in the study area. To assess the objectives remote sensing and GIS techniques were utilized. A supervised image classification technique was applied on Landsat 5 satellite images of 2000 and 2012. Five main classes such as agriculture, forest, barren land, snow and water were identified. The results showed that the area of forest, barren land, agriculture, water and snow in year 2000 was 49.54%, 43.38%, 5.19%, 1.40% and 0.49% and the area in 2012 was 37.17%, 41.36%, 12.69%, 5.05% and 3.72% respectively. Furthermore 2.02% decrease in barren land, 12.37% decrease in forest and 7.5% increase in agriculture land were identified. Due to high deforestation rate and increased agricultural activities, it is recommended that awareness campaign should be launched in the study area to protect and conserve this forest from further deforestation. 展开更多
关键词 DEforestATION CHANGE Analysis forest cover CHANGE
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Land Cover Dynamics in the Kirisia Forest Ecosystem, Samburu County, Kenya 被引量:1
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作者 Fiesta Warinwa Francis Mwaura +1 位作者 John Warui Kiringe Antony Oduya Ndubi 《Advances in Remote Sensing》 2016年第3期168-182,共15页
The study characterized the status and trend of land cover transformation in Kirisia forest ecosystem between 1973 and 2015 using remote sensing and GIS. The dominant land cover types consisted of indigenous forest fo... The study characterized the status and trend of land cover transformation in Kirisia forest ecosystem between 1973 and 2015 using remote sensing and GIS. The dominant land cover types consisted of indigenous forest followed by shrub land and bush land. The findings showed a major increase in the built environment by 55.4% and an overall reduction in forest cover by 21.3%. Up to 83.9 km2 of the original indigenous forest was lost between 1973 and 1986 due to severe fires. Thereafter, 23.7 km2 of the remaining indigenous forest was lost between 1986 and 2000 mainly through charcoal burning, illegal timber logging and livestock forage harvesting. A slight recovery occurred between 2000 and 2015 with a 5% increase in indigenous forest cover mostly through natural succession by shrub land and bush land in the burnt forest areas especially following the 1998 El Nino period. The land cover change in the forest ecosystem was not exceptional in Kenya but mirrors similar changes that have been documented in other valued dry land watershed ecosystems in the country including the national water towers. The continued loss of forest cover is likely to affect the water recharge capacity in the watershed thereby creating severe water scarcity for the people in Mararal town as well as nearly 142,954 other individuals in the Kirisia region. Appropriate interventions are therefore needed to mitigate the negative land cover change in Kirisia forest and restore its hydrological functions and water recharge capacity. 展开更多
关键词 Kirisia Watershed Ecosystem forest cover Water Supply
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Stand development patterns of forest cover types in the natural forests of northern Baekdudaegan in South Korea
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作者 Ji Hong Kim Guangze Jin Sang Hoon Chung 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第2期381-390,共10页
The purpose of this study was to classify current forest cover types,and to investigate stand development patterns for natural forests in six areas in northern Baekdudaegan,South Korea.Twenty-eight independent forest ... The purpose of this study was to classify current forest cover types,and to investigate stand development patterns for natural forests in six areas in northern Baekdudaegan,South Korea.Twenty-eight independent forest communities were aggregated into eight forest cover types by species composition in the overstory of each forest community.The forest cover types were of mixed mesophytic,‘‘others’ ’ deciduous,Quercus mongolica dominant,Q.mongolica pure,Pinus densiflora–Q.mongolica,P.densiflora,Betula ermanii,and Q.mongolica–P.koraiensis.The ecological information was organized by importance value and species diversity for each forest type.Based on the correlation between species diversity index and the abundance of Q.mongolica plus P.densiflora for corresponding forest cover types,we compared the developmental process and approximate successional pathway between each cover type.The P.densiflora forest cover type changes into the P.densiflora–Q.mongolica cover type,followed by the Q.mongolica dominant cover type through continuous invasion of the oak trees.Furthermore,the Q.mongolica pure cover type would spread toward the Q.mongolica dominant cover type with a mixture of various deciduous tree species.The Q.mongolica dominant cover type progresses through the other deciduous cover types to the mixed mesophytic cover type with diversified composition and structure.On the mid to lower slopes,with loamy soils and good moisture conditions,various deciduous forest types should progress,by ecological succession,toward the mixed mesophytic cover type without any further disturbance. 展开更多
关键词 Baekdudaegan forest cover type Species composition Species diversity Stand development PATTERNS
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Evolution of forest cover in Portugal: A review of the 12th–20th centuries
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作者 Fernando Reboredo Joo Pais 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第2期249-256,共8页
Portugal's forests in the 12th century were dominated by the Fagaceae represented by Quercus and Castanea, and several pine species From the 12th century onwards, forests underwent changes in their management startin... Portugal's forests in the 12th century were dominated by the Fagaceae represented by Quercus and Castanea, and several pine species From the 12th century onwards, forests underwent changes in their management starting with protection and ultimately leading to intense exploitation. The massive naval construction during the maritime expansion (mainly in the 15th-16th centuries) involved felling of approximately 5 million trees mainly Quercus suber, Pinus pinea and other Quercus species. Cumulative fuel-wood consumption of 959 Mm3 during 1300-1854 was attributed to demographic expansion while the deforestation rate during 1636-1854 accounted for a minimum of 72.6% and a maximum of 96% of total forest cover. The volume of timber used in railway sleepers from 1856 onwards might have reached 0.5 Mm3. The last quarter of the 20th century increased the forest cover of Portugal through the World Bank program of Eucalyptus globulus reforestation. 展开更多
关键词 forest cover change forest exploitation forest economics Portugal.
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Zonal aspects of the influence of forest cover change on runoff in northern river basins of Central Siberia
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作者 A.Onuchin Т.Burenina +2 位作者 А.Shvidenko D.Prysov A.Musokhranova 《Forest Ecosystems》 SCIE CSCD 2021年第3期602-614,共13页
Background:Assessment of the reasons for the ambiguous influence of forests on the structure of the water balance is the subject of heated debate among forest hydrologists.Influencing the components of total evaporati... Background:Assessment of the reasons for the ambiguous influence of forests on the structure of the water balance is the subject of heated debate among forest hydrologists.Influencing the components of total evaporation,forest vegetation makes a significant contribution to the process of runoff formation,but this process has specific features in different geographical zones.The issues of the influence of forest vegetation on river runoff in the zonal aspect have not been sufficiently studied.Results:Based on the analysis of the dependence of river runoff on forest cover,using the example of nine catchments located in the forest-tundra,northern and middle taiga of Northern Eurasia,it is shown that the share of forest cover in the total catchment area(percentage of forest cover,FCP)has different effects on runoff formation.Numerical experiments with the developed empirical models have shown that an increase in forest cover in the catchment area in northern latitudes contributes to an increase in runoff,while in the southern direction(in the middle taiga)extensive woody cover of catchments“works”to reduce runoff.The effectiveness of geographical zonality in regards to the influence of forests on runoff is more pronounced in the forest-tundra zone than in the zones of northern and middle taiga.Conclusion:The study of this problem allowed us to analyze various aspects of the hydrological role of forests,and to show that forest ecosystems,depending on environmental conditions and the spatial distribution of forest cover,can transform water regimes in different ways.Despite the fact that the process of river runoff formation is controlled by many factors,such as temperature conditions,precipitation regime,geomorphology and the presence of permafrost,the models obtained allow us to reveal general trends in the dependence of the annual river runoff on the percentage of forest cover,at the level of catchments.The results obtained are consistent with the concept of geographic determinism,which explains the contradictions that exist in assessing the hydrological role of forests in various geographical and climatic conditions.The results of the study may serve as the basis for regulation of the forest cover of northern Eurasian river basins in order to obtain the desired hydrological effect depending on environmental and economic conditions. 展开更多
关键词 River runoff CATCHMENTS forest cover Geographic zoning Central Siberia
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Forest cover change and its effects on the livelihood of the dependent local people:the case of Sesheke district of Zambia
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作者 Banda Arnold Sakala Enock Mulenga Mark 《宝鸡文理学院学报(自然科学版)》 CAS 2013年第4期44-49,共6页
Objective-To investigate forest cover change in Masese Local Forest Reserve and its effects on the livelihoods of the dependent communities;to establish the occurrence of forest cover change in Masese Local Forest Res... Objective-To investigate forest cover change in Masese Local Forest Reserve and its effects on the livelihoods of the dependent communities;to establish the occurrence of forest cover change in Masese Local Forest Reserve;to determine the extent of forest cover change in Masese from 1990to 2005;to determine the tree species that have been affected by forest cover change in Masese; and to assess the effects of forest cover change on the livelihoods of the dependent communities. Methods-Interviews and questionnaire were conducted with a proportion of 36households from Maondo and 84households from Mulimambango settlements.Scenes of landsat images of 1990,2000, 2005and Earth Google image for Masese were used for map analysis.Also remote sensing was used to analyze landsat images and Google image to detect forest and non-forest classes.Results and Conclusion-Forest cover change has adverse implication on the provision of wood forest products and nonwood forest products to the dependent local communities.The declining status of dominant Baikiaea Forest that has exploitable species for building materials and fuel wood has affected the livelihoods of the dependent local communities.There is also increased cost and shortage of fire wood and building materials due to deforestation in Masese Forest Reserve. 展开更多
关键词 forest cover change local communities livelihoods Masese forest reserve dependent communities
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Land Use/Land Cover and Forest Canopy Density Monitoring of Wafi-Golpu Project Area, Papua New Guinea 被引量:2
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作者 Slady Akike Sailesh Samanta 《Journal of Geoscience and Environment Protection》 2016年第8期1-14,共14页
This study aims to examine the use of Remote Sensing and Geographical Information System (GIS) technology in land use/land cover mapping to aide sustainable planning and development in the Wafi-Golpu project area. At ... This study aims to examine the use of Remote Sensing and Geographical Information System (GIS) technology in land use/land cover mapping to aide sustainable planning and development in the Wafi-Golpu project area. At the same time, this study examines an existing method of Forest Canopy Density (FCD) model to estimate forest canopy density of the proposed deforestation site, which is known as the Advanced Exploration Feasibility Study Activities (AEFSA) area within the Wafi-Golpu Project site. The FCD model calculates the forest canopy density using the three (3) indices of vegetation, soil and shadow from the Landsat-8 Operational Land Imager (OLI) satellite image of year 2013. In this study an attempt has been made to monitor the forest loss or degradation during deforestation in a natural forest stand of the Wafi-Golpu project area using forest FCD mapping and monitoring model and the findings of the study will assist the project planners and developers with their work on forest rehabilitation and reforestation for the purposes of sustainable forest management. The result of the work shows that a considerable amount of forest loss will be undertaken during the AEFSA deforestation exercise and also the findings show that a reliable land use/land cover map will greatly assist sustainable development in a resource project development period. 展开更多
关键词 Remote Sensing GIS FCD Model Land Use/Land cover forest Land Management
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Forest Cover to Double in 50 Years
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《China Population Today》 2000年第1期20-20,共1页
关键词 SFA OVER forest cover to Double in 50 Years THAN
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