Vegetation Type Map Research Articles

Distribución potencial y conectividad del paisaje: criterios para reevaluar el grado de amenaza de Campylorhynchus yucatanicus (Aves: Troglodytidae)

Geographic distribution and habitat quality are key criteria for assessing the degree of risk of species extinction threat. Campylorhynchus yucatanicus (Yucatán Wren, Troglodytidae) is an endemic bird of the Northern coast of the Yucatán Peninsula, Mexico, with a distribution restricted to a narrow strip of habitat, between Campeche and Yucatán states. Currently, the Yucatán coast has lost more than half of the coastal dune vegetation, and other habitats have been modified mainly because there is no urban development plan and the natural resources management is poor. These factors threaten C. yucatanicus, which is listed as a near threatened species by IUCN and as an endangered species by Mexican law NOM-059-2010. In this paper, C. yucatanicus´s potential distribution was modeled using 64 presence records from several sources (1960 y 2009), a set of climate variables, and a vegetation index layer of normalized difference (NDVI). To assess the degree of landscape connectivity we used a map of vegetation types and land use, distance to villages and paved roads. The potential distribution model showed an area of approximately 2 711 km2, which is 2 % of the total area of the Yucatán Peninsula distribution. In this area, only 27 % is protected by Biosphere Reserve category and only 10 % belong to core conservation areas, with land use restrictions and relatively effective protection. The populations from Ría Lagartos and Western Celestún regions appear to be the most isolated following the model of landscape connectivity. Landscape permeability among fragments of dune vegetation near the coast is low, mainly due to the distribution of urban areas. These results can be used to establish management strategies, and show that the species is in more delicate conditions than what it has been described by IUCN. We consider that C. yucatanicus should be given endangered category by IUCN, because of their distribution and the context of the current landscape connectivity.

Implementation and application of multiple potential natural vegetation models – a case study of Hungary

AbstractQuestionsMultiple potential natural vegetation (MPNV) is a framework for the probabilistic and multilayer representation of potential vegetation in an area. How can an MPNV model be implemented and synthesized for the full range of vegetation types across a large spatial domain such as a country? What additional ecological and practical information can be gained compared to traditional potential natural vegetation (PNV) estimates?LocationHungary.MethodsMPNV was estimated by modelling the occurrence probabilities of individual vegetation types using gradient boosting models (GBM). Vegetation data from the Hungarian Actual Habitat Database (MÉTA) and information on the abiotic background (climatic data, soil characteristics, hydrology) were used as inputs to the models. To facilitate MPNV interpretation a new technique for model synthesis (re‐scaling) enabling comprehensive visual presentation (synthetic maps) was developed which allows for a comparative view of the potential distribution of individual vegetation types.ResultsThe main result of MPNV modelling is a series of raw and re‐scaled probability maps of individual vegetation types for Hungary. Raw probabilities best suit within‐type analyses, while re‐scaled estimations can also be compared across vegetation types. The latter create a synthetic overview of a location's PNV as a ranked list of vegetation types, and make the comparison of actual and potential landscape composition possible. For example, a representation of forest vs grasslands in MPNV revealed a high level of overlap of the potential range of the two formations in Hungary.ConclusionThe MPNV approach allows viewing the potential vegetation composition of locations in far more detail than the PNV approach. Re‐scaling the probabilities estimated by the models allows easy access to the results by making potential presence of vegetation types with different data structure comparable for queries and synthetic maps. The wide range of applications identified for MPNV (conservation and restoration prioritization, landscape evaluation) suggests that the PNV concept with the extension towards vegetation distributions is useful both for research and application.

The long‐term legacy of geomorphic and riparian vegetation feedbacks on the dammed Bill Williams River, Arizona, USA

AbstractOn alluvial rivers, fluvial landforms and riparian vegetation communities codevelop as a result of feedbacks between plants and abiotic processes. The influence of vegetation on river channel and floodplain geomorphology can be particularly strong on dammed rivers with altered hydrology and reduced flood disturbance. We used a 56‐year series of aerial photos on the dammed Bill Williams River (Arizona, USA) to investigate how (a) different woody riparian vegetation types influence river channel planform and (b) how different fluvial landforms drive the composition of riparian plant communities over time. We mapped vegetation types and geomorphic surfaces and quantified how relations between fluvial and biotic processes covaried over time using linear mixed models. In the decades after the dam was built, woody plant cover within the river's bottomland nearly doubled, narrowing the active channel by 60% and transforming its planform from wide and braided to a single thread and more sinuous channel. Compared with native cottonwood–willow vegetation, nonnative tamarisk locally induced a twofold greater reduction in channel braiding. Vegetation expanded at different rates depending on the type of landform, with tamarisk cover on former high‐flow channels increasing 17% faster than cottonwood–willow. Former low‐flow channels with frequent inundation supported a greater increase in cottonwood–willow relative to tamarisk. These findings give insight into how feedbacks between abiotic and biotic processes in river channels accelerate and fortify changes triggered by dam construction, creating river systems increasingly distinct from predam ecological communities and landforms, and progressively more resistant to restoration of predam forms and processes.

Study of Erosion and Sediment in the Zarak Catchment Area at Yazd Province, Iran, Using Modified P.S.I.A.C, E.P.M and B.L.M Methods and Comparison of them

Yazd province is one of the arid provinces of Iran and such regions are expected to experience wind erosion. Unlike expectation, in the Zarak catchment area that is located at Yazd province, because of fixation of the soil surface, water erosion is more than wind erosion. On the other hand, due to daily temperature changes, geological formations split and then due to heavy showers, such split blocks provide ideal conditions for surface erosion. Of course, on slopes, rill erosion can be seen. Also in the waterways, when flow discharge increase, due to concentration of the kinetic energy of water in the bends of waterway, bank erosion is found. Given the importance of soil protection programs and determining the methods of management of erosion and sediment as well as the reduction of calculation and the detailed design of the dam size at the storage dams, it is necessary to estimate total size of annual erosion and sediment in a catchment area. The Zarak catchment area is no exception. On the other hand with respect to the existence of multiple methods to do this, using a method with more reasonable data and saving cost and time, in addition providing acceptable and realistic answer is needed. Of course many parameters are involved. According to these matters, in this study, to study erosion and sediment, quantitative methods of modified Pacific Southwest Inter-Agency Committee (P.S.I.A.C) and Erosion Potential Method (E.P.M), also qualitative Bureau of Land Management (B.L.M) method were used and in the end, the results were compared. With using topographic maps and aerial photos, the initial map of each type of erosion was prepared and then by combining them with data and maps of rocks sensitivity, erosion, geology, geomorphology, slopes, vegetation types and land capabilities, etc. a base map was prepared. After that, by conducting field inspection, base map’s information was controlled and status of various erosions, slope, vegetation, condition of the bed and banks of the waterways, width and depth and materials of the bed and waterways were determined. Also erosion forms classes and their ranges were identified and the most important factors involved in the intensification of erosion were identified with using modified P.S.I.A.C, E.P.M and B.L.M methods.In the end ,the results of the three methods were compared.

Assessing Threats and Conservation Status of Historical Centers of Oak Richness in California

Oak trees are emblematic of California landscapes, they serve as keystone cultural and ecological species and as indicators of natural biological diversity. As historically undeveloped landscapes are increasingly converted to urban environments, endemic oak woodland extent is reduced, which underscores the importance of strategic placement and reintroduction of oaks and woodland landscape for the maintenance of biodiversity and reduction of habitat fragmentation. This paper investigated the effects of human urban development on oak species in California by first modeling historical patterns of richness for eight oak tree species using historical map and plot data from the California Vegetation Type Mapping (VTM) collection. We then examined spatial intersections between hot spots of historical oak richness and modern urban and conservation lands and found that impacts from development and conservation vary by both species and richness. Our findings suggest that the impact of urban development on oaks has been small within the areas of highest oak richness but that areas of highest oak richness are also poorly conserved. Third, we argue that current policy measures are inadequate to conserve oak woodlands and suggest regions to prioritize acquisition of conservation lands as well as examine urban regions where historic centers of oak richness were lost as potential frontiers for oak reintroduction. We argue that urban planning could benefit from the adoption of historical data and modern species distribution modelling techniques primarily used in natural resources and conservation fields to better locate hot spots of species richness, understand where habitats and species have been lost historically and use this evidence as incentive to recover what was lost and preserve what still exists. This adoption of historical data and modern techniques would then serve as a paradigm shift in the way Urban Planners recognize, quantify, and use landscape history in modern built environments.

Exploiting Differential Vegetation Phenology for Satellite-Based Mapping of Semiarid Grass Vegetation in the Southwestern United States and Northern Mexico

We developed and evaluated a methodology for subpixel discrimination and large-area mapping of the perennial warm-season (C4) grass component of vegetation cover in mixed-composition landscapes of the southwestern United States and northern Mexico. We describe the methodology within a general, conceptual framework that we identify as the differential vegetation phenology (DVP) paradigm. We introduce a DVP index, the Normalized Difference Phenometric Index (NDPI) that provides vegetation type-specific information at the subpixel scale by exploiting differential patterns of vegetation phenology detectable in time-series spectral vegetation index (VI) data from multispectral land imagers. We used modified soil-adjusted vegetation index (MSAVI2) data from Landsat to develop the NDPI, and MSAVI2 data from MODIS to compare its performance relative to one alternate DVP metric (difference of spring average MSAVI2 and summer maximum MSAVI2), and two simple, conventional VI metrics (summer average MSAVI2, summer maximum MSAVI2). The NDPI in a scaled form (NDPIs) performed best in predicting variation in perennial C4 grass cover as estimated from landscape photographs at 92 sites (R2 = 0.76, p < 0.001), indicating improvement over the alternate DVP metric (R2 = 0.73, p < 0.001) and substantial improvement over the two conventional VI metrics (R2 = 0.62 and 0.56, p < 0.001). The results suggest DVP-based methods, and the NDPI in particular, can be effective for subpixel discrimination and mapping of exposed perennial C4 grass cover within mixed-composition landscapes of the Southwest, and potentially for monitoring of its response to drought, climate change, grazing and other factors, including land management. With appropriate adjustments, the method could potentially be used for subpixel discrimination and mapping of grass or other vegetation types in other regions where the vegetation components of the landscape exhibit contrasting seasonal patterns of phenology.

Rescuing and Sharing Historical Vegetation Data for Ecological Analysis: The California Vegetation Type Mapping Project

Research efforts that synthesize historical and contemporary ecological data with modeling approaches improve our understanding of the complex response of species, communities, and landscapes to changing biophysical conditions through time and in space. Historical ecological data are particularly important in this respect. There are remaining barriers that limit such data synthesis, and technological improvements that make multiple diverse datasets more readily available for integration and synthesis are needed. This paper presents one case study of the Wieslander Vegetation Type Mapping project in California and highlights the importance of rescuing, digitizing and sharing historical datasets. We review the varied ecological uses of the historical collection: the vegetation maps have been used to understand legacies of land use change and plan for the future; the plot data have been used to examine changes to chaparral and forest communities around the state and to predict community structure and shifts under a changing climate; the photographs have been used to understand changing vegetation structure; and the voucher specimens in combination with other specimen collections have been used for large scale distribution modeling efforts. The digitization and sharing of the data via the web has broadened the scope and scale of the types of analysis performed. Yet, additional research avenues can be pursued using multiple types of VTM data, and by linking VTM data with contemporary data. The digital VTM collection is an example of a data infrastructure that expands the potential of large scale research through the integration and synthesis of data drawn from numerous data sources; its journey from analog to digital is a cautionary tale of the importance of finding historical data, digitizing it with best practices, linking it with other datasets, and sharing it with the research community.

Rescuing and Sharing Historical Vegetation Data for Ecological Analysis: The California Vegetation Type Mapping Project

Research efforts that synthesize historical and contemporary ecological data with modeling approaches improve our understanding of the complex response of species, communities, and landscapes to changing biophysical conditions through time and in space. Historical ecological data are particularly important in this respect. There are remaining barriers that limit such data synthesis, and technological improvements that make multiple diverse datasets more readily available for integration and synthesis are needed. This paper presents one case study of the Wieslander Vegetation Type Mapping project in California and highlights the importance of rescuing, digitizing and sharing historical datasets. We review the varied ecological uses of the historical collection: the vegetation maps have been used to understand legacies of land use change and plan for the future; the plot data have been used to examine changes to chaparral and forest communities around the state and to predict community structure and shifts under a changing climate; the photographs have been used to understand changing vegetation structure; and the voucher specimens in combination with other specimen collections have been used for large scale distribution modeling efforts. The digitization and sharing of the data via the web has broadened the scope and scale of the types of analysis performed. Yet, additional research avenues can be pursued using multiple types of VTM data, and by linking VTM data with contemporary data. The digital VTM collection is an example of a data infrastructure that expands the potential of large scale research through the integration and synthesis of data drawn from numerous data sources; its journey from analog to digital is a cautionary tale of the importance of finding historical data, digitizing it with best practices, linking it with other datasets, and sharing it with the research community.

California's Historic Legacy For Landscape Change, the Wieslander Vegetation Type Maps

Abstract This paper presents the digitized edition of the Wieslander Vegetation Type Maps (VTMs). The VTMs were part of the first statewide systematic survey of California's vegetation, conducted 1928–1939. Under the direction of Albert Wieslander, crews recorded the patterns of vegetation that they observed from vantage points across the state. The survey covers 176,901 km2 including border and lake polygons and 165,652 km2 of landscapes that we describe in more detail. There are 251,541 polygons in the full extent of the maps, with 249,630 in the analysis extent. These polygons are annotated with codes indicating the dominant plant species, for which voucher specimens were collected. The maps contain 655 species codes, representing 535 species or sub-species in 229 genera, including 34 Arctostaphylos Adans. and 16 Quercus L. species. The 249,630 polygons contain 26,013 unique combinations of species and levels of disturbance. These can be classified into 525 vegetation alliances or provisional alliances...

甘肃安西极旱荒漠国家级自然保护区南片植被长势与保护成效

PDF HTML阅读 XML下载 导出引用 引用提醒 甘肃安西极旱荒漠国家级自然保护区南片植被长势与保护成效 DOI: 10.5846/stxb201408191645 作者: 作者单位: 北京林业大学，环境保护部南京环境科学研究所,北京林业大学，环境保护部南京环境科学研究所,北京林业大学,甘肃安西极旱荒漠国家级自然保护区管理局 作者简介: 通讯作者: 中图分类号: 基金项目: 林业公益性行业科研专项(201104029) Vegetation growth and conservation efficacy assessment in the Southern Part of the Gansu Anxi National Nature Reserve in Hyper-Arid Desert Author: Affiliation: Beijing Forestry University，Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection,Beijing Forestry University，Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection,Beijing Forestry University,Adminstration of Gansu Anxi National Nature Reserve in Hyper-Arid Desert Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以甘肃安西极旱荒漠国家级自然保护区南片为研究案例,借助高分辨率遥感影像和GIS技术,结合具体的植被类型和功能区划,分析了2000年到2010年间自然保护区内植被长势趋势的变化。结果发现:(1)11年来各植被类型,尤其是以骆驼刺、芦苇、芨芨草为主的天然草地植被表现出了较好的长势和增长的趋势;(2)核心区和缓冲区内不存在退化的植被类型,表明自然保护区基本实现了保护目的;(3)退化的植被位于实验区的布隆吉村、桥子村和双塔村,面积为1319 hm2,占比为0.31%。由此可见甘肃安西极旱荒漠国家级自然保护区南片植被保护成效明显。将植被长势趋势分析同自然保护区功能区划及植被类型相结合,希望有助于识别保护要点,以便为植被保护成效评价提供参考。 Abstract:Deserts are vulnerable ecosystems formed under severe environmental conditions, and climatic anomalies and human disturbance can have irreversible impacts on wild animals, plants, and the natural environment of these ecosystems. Desert ecosystems perform irreplaceable eco-service functions, providing protection against wind, stabilizing sand, acting as biogeographic barriers, and promoting the conservation of biodiversity. Moreover, vegetation plays a crucial role in the assessment of ecological changes. Accordingly, by analyzing changes in vegetation, ecological threats can be identified and their severity quantified, thus helping to assess conservation efficacy in nature reserves. China is one of several countries worldwide suffering from severe desertification over vast areas, that is both extensive and complex. Accordingly, it is critical to understand conservation efficacy in the desert ecosystems of China's nature reserves. The Gansu Anxi National Nature Reserve in Hyper-Arid Desert (GANNR) is the only reserve in China established to protect hyper-arid desert ecosystems and their biodiversity; it is located in Guazhou County in the western part of the Hexi Corridor, Gansu Province. GANNR covers approximately 8000 km2, and thus accounts for one third of the total area of Guazhou County. The reserve separates the Kumutage and Badain Jaran deserts, sheltering the Hexi Corridor oasis and preventing sandstorms. Accordingly, it plays a critical role in biodiversity conservation and regional eco-safety. GANNR is divided into two parts: the northern and southern reserves. As the Chinese government has implemented its western development strategy, some key national projects have extended across the northern part of GANNR, including infrastructure for west-east natural gas transmission, west-east power transmission, and the Lan-Xin railway. In this study, we selected the southern part of GANNR as our study area for several reasons: (1) the vegetation cover and species richness are higher here than in the north; (2) typical temperate desert vegetation such as Reaumuria soongorica, Salsola passerina, Sympegma regelii, and Ephedra przewalskii can be found and assessed in the south; and (3) some villages are located in the southern part of our study zone. We analyzed trends in vegetative growth from 2000 to 2010, using RS and GIS by combining vegetation type and functional zoning maps. The vegetation type map was created using a high-resolution remote sensing image, which was acquired from the ZY-1-02C satellite in August 2012. This image had a spatial resolution of 2.36 m, after processing in ENVI 5.0 using orthorectification and the Gram-Schmidt method. Regression analysis of NDVI and elapsed time revealed the vegetation growth trend for each vegetation type in different functional zones. The results show the following: (1) each vegetation type exhibited increased growth over time, with an increasing trend during the 11-year period. This was particularly true for the natural grassland, which included Alhagi sparsifolia, Phragmites australis, and Achnatherum splendens; (2) no degraded vegetation types were found in either the core zone or the buffer zone, indicating that the GANNR administration achieved their protection goal; and (3) degraded vegetation types were found in the Bulongji, Qiaozi, and Shuangta villages, covering an area of 1319 hm2; this corresponds to just 0.31% of the study area. Although we have clearly demonstrated the vegetation conservation efficacy in GANNR, we also make the following suggestions: (1) adjust the functional zoning, such that the area containing Ephedra przewalskii is incorporated into the buffer or core zones; and (2) strengthen supervision around the villages to maintain the grassland conservation results achieved previously by constructing a fence to return grazing land to grass. We hope that this study will be beneficial to the GANNR administration, and will act as a reference for future vegetation conservation efficacy assessments. 参考文献 相似文献 引证文献

Habitat preference for fire scars by feral cats in Cape York Peninsula, Australia

Context Feral cats are implicated in the decline of terrestrial native mammals across northern Australia. Research in the Kimberley region of north-western Australia found feral cats strongly selected for fire scars when hunting, suggesting that intensifying fire regimes will have severe consequences for declining prey species. Aims We tested the generality of cat–fire interaction beyond the Kimberley, by measuring habitat selection of feral cats in relation to fire scars and habitat types in north-eastern Australia. Methods Our study was conducted at Piccaninny Plains Wildlife Sanctuary, Cape York Peninsula. We live-captured feral cats during the dry season of 2015, released them with GPS collars set to record fixes at 15-min intervals, and recaptured cats 4 months later. We created dynamic habitat maps of vegetation types, fire and wetlands, and compared cat habitat selection using discrete choice modelling. We also measured cat density from arrays of camera traps and examined cat diet by analysis of stomach contents. Key results We obtained GPS movement data from 15 feral cats. Feral cats selected strongly for recent fire scars (1 or 2 months old), but avoided fire scars 3 months old or older. Three long-distance movements were recorded, all directed towards recent fire scars. Cats also selected for open wetlands, and avoided rainforests. Density of cats at Piccaninny Plains was higher than recorded elsewhere in northern Australia. All major vertebrate groups were represented in cat diet. Conclusions We showed that feral cats in north-eastern Australia strongly select for recent fire scars and open wetlands. These results are consistent with those from the Kimberley. Together, these studies have shown that amplified predation facilitated by loss of cover is likely to be a fundamental factor driving mammal decline across northern Australia. Implications Reducing the frequency of intense fires may indirectly reduce the impact of feral cats at a landscape scale in northern Australia. We also suggest that managers target direct cat control towards open wetlands and recently burnt areas, which cats are known to favour.

Seasonal change monitoring and mapping of coastal vegetation types along Midnapur-Balasore Coast, Bay of Bengal using multi-temporal landsat data

The present study highlights the application of satellite remote sensing in seasonal change monitoring and mapping of coastal vegetation types along Midnapur-Balasore coast, Bay of Bengal, using multi-temporal satellite images of Landsat ETM+ of 2000, 2001 and 2002 of pre-monsoon and post-monsoon seasons. Two types of image analysis techniques were applied in this study to identify different species of coastal vegetations, health and their areal extent. RGB-NDVI was computed to detect and monitor the changes of vegetation health during pre and post-monsoon period. Another technique is supervised digital classification was used for mapping of different coastal vegetations and to determine their spatial extent of the study area. Five major coastal vegetation types were delineated using satellite data viz., dune vegetation, mangroves, salt marsh, agricultural lands and other vegetations. An attempt has been made to analyze seasonal change monitoring and mapping of different coastal vegetations communities including mangroves, salt marsh, and dune vegetation from 2000 to 2002 using Landsat 7 ETM+ data. From 2000 to 2002 it is observed that the areal extent of salt marsh and dune vegetation is changed seasonally along each littoral cell. It is increased during post-monsoon season and decrease during pre-monsoon season. In this period, the gain of 704.34 ha area of salt marsh and 2153.88 ha area of dune vegetations cover was noticed. During post-monsoon period the mangrove vegetation covers along all littoral cells have increased this may be due to supply of huge amount of sediment and increase of salinity condition after monsoon. But over the entire 3 years period from pre-monsoon 2000 to post-monsoon 2002 the net change was negative, which was quantified as 61.83 ha. The depletion of mangroves may be due to high anthropogenic pressure, commercial aquaculture, highly eroding nature of the coast and tidal activities. The NDVI derived from ETM+ images provide useful information to monitor coastal vegetation changes, especially the natural plants growing on sand dunes, mangroves and salt marsh vegetations. The analysis of NDVI variations showed the qualitative information about the vegetation. On the other hand classified image provide quantitative information about the coastal vegetation.

Current and Future Fire Regimes and Their Influence on Natural Vegetation in Ethiopia

Fire is a major factor shaping the distribution of vegetation types. In this study, we used a recent high resolution map of potential natural vegetation (PNV) types and MODIS fire products to model and investigate the importance of fire as driver of vegetation distribution patterns in Ethiopia. We employed statistical modeling techniques to estimate the distribution of fire and the PNVs under current climatic conditions, and used the calibrated models to project distributions for different climate change scenarios. Results show a clear congruence between distribution patterns of fire and major vegetation types. The effect of climate change varies considerably between climate change models and scenarios, but as general trend expansions of moist Afromontane forest and Combretum–Terminalia woodlands were predicted. Fire-prone areas were also predicted to increase, and including this factor in vegetation distribution models resulted in stronger expansion of Combretum–Terminalia woodlands and a more limited increase of moist Afromontane forests. These results underline the importance of fire as a regulating factor of vegetation distribution patterns, and how fire needs to be factored into predict the possible effects of climate change. For conservation strategies to effectively address conservation challenges caused by rapid climate shifts, it is imperative that they not only consider the direct influence of climate changes on the vegetation, species species, or biodiversity patterns, but also the influence of future fire regimes.

The Spanish and Mexican Baseline of California Tree and Shrubland Distributions Since the Late 18th Century

Historical distributions of 31 tree species, chaparral, and coastal sage scrub described by Spanish land explorers in the late eighteenth and early nineteenth centuries (1769–1806) and in land grant diseños (1784–1846) are reconstructed at 634 localities across central and southern California. This baseline predates most formal botanical surveys by nearly a century, allowing for assessment of vegetation change over the broadest time frame for comparison with pre-historical evidences and future distributions. Spanish accounts are compared with historical sources in the Mexican era (1821–1848), American settlement (1848–1929), and modern range maps of the 1929–1934 Vegetation Type Map (VTM) survey. Among tree species that were recorded in Spanish explorations, the site-specific localities are consistent with VTM maps at the spatial resolution of the land expeditions. In contrast with massive deforestation across eastern North America since European colonization, hardwood and conifer forests in California sustained inconsequential cutting during Hispanic settlement. Spanish accounts and Mexican diseños occasionally provide remarkable detail of fine-scale distributions which have not changed over the past two centuries, including Pinus radiata forest at Cambria and Monterey, the eastern limit of Quercus lobata and Q. agrifolia woodlands with Aesculus californica in the Salinas Valley, as well as isolated stands of Cupressus macrocarpa and C. sargentii. Disjunct occurrences of trees in southern California were recorded at the same places they occur today, including an isolated grove of Q. engelmannii at the Baldwin Park Arboretum, and the Pinus coulteri stand in the mountains above Santa Barbara. The southern margin of mixed conifer forest in the San Bernardino Mountains has remained on the crest of the range since Garcés’ account in 1776. Long-term tree distributions are evaluated with respect to land use, grazing and climate change. We advocate the use of historical records as proxy data for climate change studies.

Bioclimatic map of Tay Nguyen at scale 1:250,000 for setting up sustainable ecological economic models

A study on development of a system for bioclimatic classification criteria and construction of a bioclimatic map of Tay Nguyen region at scale of 1/250,000 was conducted, based on statistical analysis of bioclimatic characteristics of Tay Nguyen, comparing with those of other regions of Vietnam. The system of classification criteria was developed based on 4 factors, namely: mean annual temperature (TN), total annual rainfall (RN), length of cold season (N) and length of dry season length (n). The thermal-humid indicators, featuring seasonal constraints (for tropical plants) as well as the thresholds for their division, were selected based on the ecological characteristics of vegetation and their role for the formulation, structure, appearance of the natural vegetation types of Tay Nguyen region. Results showed bioclimatic resources of Tay Nguyen territory is rich and diverse reflecting in 23 different bioclimatic units of a total of 57 separate polygons. That partly explains the diversity of vegetation types ofTay Nguyen. Study of bioclimatic classification has both a scientific and practical significance. Bioclimatic classification provides an important information for mapping ecological landscape of Tay Nguyen; A bioclimatic resource assessment of a specific territory is a necessary scientific basis for proposing the development orientation of economic sectors and establishment of sample sustainable economic models in Tay Nguyen territory.References Lam Cong Dinh, 1992: Bioclimatic applications in forestry in Vietnam. Science and Technology Publishing House, Hanoi. Houérou, H.N., Popov, G.F., See, L., 1993: Agrobioclimatic Classification of Africa (Working paper) - FAO Agrometeorogy Series, N° 6. 227 pp. Vu Tu Lap, 2002: Vietnam natural geography.Education Publishing House, Hanoi. Legris, P., Blasco, F., 1989: Classification and mapping of vegetation types in tropical Asia (Reviewed by K.D. Singh) - FAO of the United Nations, Rome. 135 pp. Nguyen DucNgu, 1988: Climate of Tay Nguyen. Monographs of 2ndTay Nguyen Program. Vietnam Academy of Science and Technology. Thai Van Trung, 1978: Eco-genesis and classification of forest vegetation of Vietnam (From ecosystem perspective), Second edition, with correction, Science and Techniques Publishing House, Ha Noi. 276 pp. (In Vietnamese, Resume in French, Summary in English, Russian and Spanish). Nguyen Khanh Van, 1993: Bioclimatic Typology of Vietnam - Journal Izvestia, Geographical Series, Russian Academy of Sciences, Moscow (6) pp. 114-123 (in Russian: НгуенКханьВан1993:ТипологиябиослиматовВьетнама. Известия,СерияГеографическая, РоссийскаяАкадемияНаук, Москва). Nguyen Khanh Van, 2006: Bioclimatic basis (Master curriculum), Hanoi Pedagogical University Publishing House of. Nguyen Khanh Van, Nguyen ThiHien, 1999: The available methods of bioclimatic classification in Vietnam. Vietnam Journal of Earth Sciences No. 2, Academy of Science and Technology of Vietnam, Hanoi.

Classification of Vegetation Types in the Habitat of White-Tailed Deer in a Location of the Tehuacán-Cuicatlán Biosphere Reserve, Mexico

This paper classifies the vegetation types that comprise the habitat of the white-tailed deer Odocoileus virginianus at a location within the Tehuacan-Cuicatlan Biosphere Reserve (TCBR) in Mexico. The vegetation was sampled, identified, and mapped at 308 points distributed along 28 transects (each of 500 m in length). To determine the effect of the classified and mapped vegetation types on the white-tailed deer, we estimated population density using the PELLET procedure based on the pellet-group count method. The principal vegetation types at the study site are tropical dry forest (TDF, 63% of the area) dominated by tetecho ( Neobuxbaumia tetezo), uña de gato ( Mimosa spp.) and mulato ( Bursera spp.), and crassicaule scrub dominated by mantecoso ( Parkinsonia praecox). The TDF can be sub-classified into four spatially different clusters (vegetation types) depending on the dominance of these species. The white-tailed deer population density varied significantly depending on vegetation type. Our results contribute to the ecological knowledge of the white-tailed deer in tropical habitats and are of value for the implementation of effective conservation and management.

New vegetation type map of India prepared using satellite remote sensing: Comparison with global vegetation maps and utilities

A seamless vegetation type map of India (scale 1: 50,000) prepared using medium-resolution IRS LISS-III images is presented. The map was created using an on-screen visual interpretation technique and has an accuracy of 90%, as assessed using 15,565 ground control points. India has hitherto been using potential vegetation/forest type map prepared by Champion and Seth in 1968. We characterized and mapped further the vegetation type distribution in the country in terms of occurrence and distribution, area occupancy, percentage of protected area (PA) covered by each vegetation type, range of elevation, mean annual temperature and precipitation over the past 100 years. A remote sensing-amenable hierarchical classification scheme that accommodates natural and semi-natural systems was conceptualized, and the natural vegetation was classified into forests, scrub/shrub lands and grasslands on the basis of extent of vegetation cover. We discuss the distribution and potential utility of the vegetation type map in a broad range of ecological, climatic and conservation applications from global, national and local perspectives. We used 15,565 ground control points to assess the accuracy of products available globally (i.e., GlobCover, Holdridge’s life zone map and potential natural vegetation (PNV) maps). Hence we recommend that the map prepared herein be used widely. This vegetation type map is the most comprehensive one developed for India so far. It was prepared using 23.5m seasonal satellite remote sensing data, field samples and information relating to the biogeography, climate and soil. The digital map is now available through a web portal (http://bis.iirs.gov.in).

中国西北干旱区植被碳汇估算及其时空格局

PDF HTML阅读 XML下载 导出引用 引用提醒 中国西北干旱区植被碳汇估算及其时空格局 DOI: 10.5846/stxb201405211045 作者: 作者单位: 西北师范大学 地理与环境科学学院,北京师范大学 资源学院 作者简介: 通讯作者: 中图分类号: S812；F062； 基金项目: 国家自然科学基金项目(41361040);甘肃省自然科学基金项目(1208RJZA159);甘肃省高校基本科研业务费项目(2014-63) Estimation and spatial-temporal characteristics of carbon sink in the arid region of northwest China Author: Affiliation: College of Geographic and Environmental Science,Northwest Normal University,College of Resources Science, Beijing Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:通过修正的CASA模型估算2001-2012年间西北干旱区陆地生态系统的净第一性生产力(NPP),并结合土壤微生物呼吸方程,计算出12a的净生态系统生产力(NEP),分析了植被碳汇的时空变化规律。结果表明:研究区的NPP表现出很强的随季节变化的规律,全年7月份NPP为最高值,12月为最低值,12 年间NPP的年均值变化不大。2001-2012 年研究区的植被碳汇在波动变化中有所增加,其中2006年的碳汇平均值最小,为609.04 gC m-2 a-1,2012年最大,为648.02 gC m-2 a-1;年内碳汇的最大值主要出现在5-7月;碳汇能力由大到小的植被类型为针叶林 > 农田 > 灌丛 > 阔叶林 > 草原 > 荒漠草原。研究区多年平均碳汇量呈现自西向东逐渐增加的规律,西辽河流域草原区的NPP和碳汇平均值最大,塔里木盆地暖温带荒漠区最小。 Abstract:Global warming caused by greenhouse gas emissions has had a profound impact on human survival and development. Consequently, this phenomenon has received widespread attention from the international community. Vegetation can absorb greenhouse gases CO2, and has a huge carbon sink function, so it has an irreplaceable role in slowing global warming. The carbon sink capacity of vegetation has a significant impact on regional and global climate change. Carbon emissions are undoubtedly enormous in the mid and high latitudes of the Northern Hemisphere, so studies on terrestrial ecosystem carbon dynamics and spatial patterns in the arid region of northwest China may provide an accurate assessment how China contributes towards mitigating global climate change and CO2 emission reduction. The net primary productivity (NPP) and heterotrophic respiration (RH) in the arid region of northwest China were calculated by using MODIS images, meteorological data, and a vegetation type map, in combination with an improved CASA model and soil microbial respiration model. The NPP and RH were then used to estimate net ecosystem productivity (NEP) and vegetation carbon sink from 2001 to 2012. Spatial-temporal characteristics and the reasons for NPP and carbon sink variation in the arid region of northwest China were analyzed. The results show that research methods used in this paper were able to quickly extract ecosystem net primary productivity and carbon sink for the northwest arid region. The methods used are efficient, convenient, and practical for large scale carbon balance and carbon cycling studies in this region. Comparison indicated small gaps between simulated and measured site values. The overall difference in the spatial distribution between simulated values and MODIS NPP products is also small, and the volatility of the analog value is less than the value of MODIS NPP products. NPP in the study area showed strong seasonal variation. The maximal NPP value was obtained in July, while the minimum value was obtained in December. In the 12 study years, annual averages of NPP changed minimally. Average carbon sinks showed fluctuating in the 12 years, but increased in general, overall. The carbon sink mean changed from a minimum of 609.04 gC-1m-2a-1 in 2006 to a maximum of 648.02 gC-1m-2a-1 in 2012. The change in mean carbon sink was less than 39 gC-1m-2a-1, with a standard deviation of 11.68. Annual maximum carbon mainly occurred in May, June, and July. Carbon sink fluctuated, but showed an overall upward trend in the northwest arid region between 2001 and 2012. Carbon sink in this region gradually increased from West to East, with Eastern > West > Central. The carbon sink capacity of different natural areas was quite different. The largest carbon sink capacity was recorded in the grassland area of West Liaohe River Basin, while the smallest was recorded in the warm temperate desert region of the Tarim Basin. The annual maximum carbon sink mainly occurred from May to July. Carbon sink was ranked in the order of coniferous forest > farmland > shrubs > broad-leaved forest > grassland > desert steppe. 参考文献 相似文献 引证文献

Effective Management of Trans boundary Landscapes – Geospatial Applications

Abstract. The Convention on Biological Diversity advocates the use of landscape and ecosystem approaches for managing biodiversity, in recognition of the need for increased regional cooperation. In this context, ICIMOD and regional partners have evolved Transboundary Landscape concept to address the issues of conservation and sustainable use of natural resources and systems (e.g., biodiversity, rangelands, farming systems, forests, wetlands, and watersheds, etc.). This concept defines the landscapes by ecosystems rather than political/administrative boundaries. The Hindu Kush Himalayan (HKH) region is extremely heterogeneous, with complex inter linkages of biomes and habitats as well as strong upstream-downstream linkages related to the provisioning of ecosystem services. Seven such transboundary landscapes, identified across west to east extent of HKH, have been considered for programmatic cooperation, include: Wakhan, Karakoram-Pamir, Kailash, Everest, Kangchenjunga, Brahmaputra-Salween, and Cherrapunjee- Chittagong. The approach is people centered and considers the cultural conservation as an essential first step towards resource conservation efforts in the region. Considering the multi-scale requirements of study, the geospatial technology has been effectively adopted towards: (i) understanding temporal changes in landscapes, (ii) long term ecological and social monitoring, (ii) identifying potential bio corridors, (iii) assessing landscape level vulnerability due to climatic and non-climatic drivers, and (iv) developing local plans on extractions of high value economic species supporting livelihoods, agroforestry system and ecotourism, etc. We present here our recent experiences across different landscapes on assessment of three decadal changes, vegetation type mapping, assessment of socio-ecological drivers, corridor assessment, ecosystem services assessment, models for optimal natural resource use systems and long term socio-ecological monitoring.

Geospatial data sharing, online spatial analysis and processing of Indian Biodiversity data in Internet GIS domain – A case study for raster based online geo-processing

Abstract. National Biodiversity Characterization at Landscape Level, a project jointly sponsored by Department of Biotechnology and Department of Space, was implemented to identify and map the potential biodiversity rich areas in India. This project has generated spatial information at three levels viz. Satellite based primary information (Vegetation Type map, spatial locations of road & village, Fire occurrence); geospatially derived or modelled information (Disturbance Index, Fragmentation, Biological Richness) and geospatially referenced field samples plots. The study provides information of high disturbance and high biological richness areas suggesting future management strategies and formulating action plans. The study has generated for the first time baseline database in India which will be a valuable input towards climate change study in the Indian Subcontinent. The spatial data generated during the study is organized as central data repository in Geo-RDBMS environment using PostgreSQL and POSTGIS. The raster and vector data is published as OGC WMS and WFS standard for development of web base geoinformation system using Service Oriented Architecture (SOA). The WMS and WFS based system allows geo-visualization, online query and map outputs generation based on user request and response. This is a typical mashup architecture based geo-information system which allows access to remote web services like ISRO Bhuvan, Openstreet map, Google map etc., with overlay on Biodiversity data for effective study on Bio-resources. The spatial queries and analysis with vector data is achieved through SQL queries on POSTGIS and WFS-T operations. But the most important challenge is to develop a system for online raster based geo-spatial analysis and processing based on user defined Area of Interest (AOI) for large raster data sets. The map data of this study contains approximately 20 GB of size for each data layer which are five in number. An attempt has been to develop system using python, PostGIS and PHP for raster data analysis over the web for Biodiversity conservation and prioritization. The developed system takes inputs from users as WKT, Openlayer based Polygon geometry and Shape file upload as AOI to perform raster based operation using Python and GDAL/OGR. The intermediate products are stored in temporary files and tables which generate XML outputs for web representation. The raster operations like clip-zip-ship, class wise area statistics, single to multi-layer operations, diagrammatic representation and other geo-statistical analysis are performed. This is indigenous geospatial data processing engine developed using Open system architecture for spatial analysis of Biodiversity data sets in Internet GIS environment. The performance of this applications in multi-user environment like Internet domain is another challenging task which is addressed by fine tuning the source code, server hardening, spatial indexing and running the process in load balance mode. The developed system is hosted in Internet domain (http://bis.iirs.gov.in) for user access.