检索结果-南通市图书馆

Analysis of the inflection points of height-diameter models

forest Ecosystems 2024年第4期11卷 414-422页

作者： Tzeng Yih Lam Mark J.Ducey Department of forest Resources Management Faculty of ForestryThe University of British Columbia2045-2424 Main MallVancouverBCV6T 1Z4 Canada Department of Natural Resources and the Environment University of New Hampshire114 James HallDurhamNH 03824USA

The inflection point is an important feature of sigmoidal height-diameter(H-D)*** is often cited as one of the properties favoring sigmoidal model ***,there are very few studies analyzing the inflection points of H-D *** goals of this study were to theoretically and empirically examine the behaviors of inflection points of six common H-D models with a regional *** six models were the Wykoff(WYK),schumacher(sCH),Curtis(CuR),HossfeldⅣ(HOs),von Bertalanffy-Richards(VBR),and Gompertz(GPZ)*** models were first fitted in their base forms with tree species as random effects and were then expanded to include functional traits and spatial *** distributions of the estimated inflection points were similar between the two-parameter models WYK,sCH,and CuR,but were different between the threeparameter models HOs,VBR,and *** produced some of the largest inflection *** and VBR produced concave H-D curves without inflection points for 12.7%and 39.7%of the tree *** species or decreasing shade tolerance resulted in larger inflection *** trends in the estimated inflection points of HOs and VBR were entirely opposite across the ***,HOs could produce concave H-D curves for portions of the *** on the studied behaviors,the choice between two-parameter models may not *** recommend comparing seve ral three-parameter model forms for consistency in estimated inflection points before deciding on *** sigmoidal models to have inflection points does not necessarily mean that they will produce fitted curves with *** study highlights the need to integrate analysis of inflection points into modeling H-D relationships.

关键词： Concavity forest inventory and analysis Generalized height-diameter models Growth functions Height-diameter functions Mixed-effects modeling Points of inflection species-specific models

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Land Breeze and Thermals: A scale Threshold to Distingu.s. Their Effects

引用

Advances in Atmospheric sciences 2005年第6期22卷 889-902页

作者： Yongqiang LIu forestry sciences Laboratory USDA Forest Service 320 Green Street Athens GA 30602 USA

Land breeze is a type of mesoscale circulation developed due to thermal forcing over a heterogeneous landscape. It can contribute to atmospheric dynamic and hydrologic processes through affecting heat and water fluxes on the land-atmosphere interface and generating shallow convective precipitation. If the scale of the landscape heterogeneity is smaller than a certain size, however, the resulting land breeze becomes weak and becomes mixed up with other thermal convections like thermals. This study seeks to identify a scale threshold to distingu.s. the effects between land breeze and thermals. Two-dimensional simulations were performed with the Regional Atmospheric Modeling system （RAMs） to simulate thermals and land breeze. Their horizontal scale features were analyzed using the wavelet transform. The thermals developed over a homogeneous landscape under dry or wet conditions have an initial scale of 2-5 km during their early stage of development. The scale jumps to 10-15 km when condensation occu.s. The solution of an analytical model indicates that the reduced degree of atmospheric instability due to the release of condensation potential heat could be one of the contributing factors for the increase in scale. The land breeze, on the other hand, has a major scale identical to the size of the landscape heterogeneity throughout various stages of development. The results suggest that the effects of land breeze can be clearly distingu.s.ed from those of thermals only if the size of the landscape heterogeneity is larger than the scale threshold of about 5 km for dry atmospheric processes or about 15 km for moist ones.

关键词： land breeze thermals horizontal scale large-eddy simulation wavelet transform

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

EMDs 3.0:A modeling framework for coping with complexity in environmental assessment and planning

引用

science China(Technological sciences) 2006年第z1期49卷 63-75页

作者： Keith M.Reynolds u.s.Dept.Agriculture Forest ServicePacific Northwest Research Station3200 SW Jefferson WayCorvallisOR 97331USA

The Ecosystem Management Decision support (EMDs) system is an application framework for knowledge-based decision support of ecological assessments at any geographic scale. The system integrates state-of-the-art geographic information system (GIs) as well as knowledge-based reasoning and decision modeling technologies to provide decision support for a su.s.antial portion of the adaptive management process of ecosystem management. EMDs 3.0 is implemented as an ArcMap extension and integrates the logic engine of NetWeaver to perform landscape evaluations, and the decision modeling engine of Criterium DecisionPlus for evaluating management priorities. Key features of the system's evaluation component include abilities to (1) reason about large, abstract, multi-faceted ecosystem management problems, (2) perform useful evaluations with incomplete information, (3) evaluate the influence of missing information, and (4) determine priorities for missing information. A key feature of the planning component is the ability to determine priorities for management activities, taking into account not only ecosystem condition, but also criteria that account for the feasibility and efficacy of potential management actions. Both components include powerful and intuitive diagnostic features that facilitate communicating the explanation of modeling results to a broad audience.

关键词： natural resources, modeling, assessment, analysis, planning, software, ecosystem management.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Rangeland restoration in Jordan:Restoring vegetation cover by water harvesting measures

引用

International soil and Water Conservation Research 2022年第4期10卷 610-622页

作者： Mira Haddad stefan Martin strohmeier Kossi Nouwakpo Omar Rimawi Mark Weltz Geert sterk Restoration Initiative on Dryland Ecosystem Resilient Agrosilvopastoral Systems(RASP)International Center for Agricultural Research in the Dry Areas(ICARDA)AmmanJordan Department of Water Atmosphere and EnvironmentInstitute of Soil Physics and Rural Water ManagementUniversity of Natural Resources and Life SciencesViennaAustria Northwest Irrigation and soils Research Laboratory Agriculture Research Service(ARS)United States Department for Agriculture(USDA)KimberlyIDUSA Department of Applied and Environmental Geology Faculty of ScienceThe University of JordanAmmanJordan Great Basin Rangelands Research Agriculture Research Service(ARS)United State Department for Agriculture(USDA)RenoNVUSA Geosciences Department of Physical GeographyUtrecht UniversityUtrechtthe Netherland

Restoration of the degraded rangelands in Jordan using mechanized water harvesting and native species planting has become key to enhancing and maintaining the productivity and resilience of fragile ecosystems.A balanced interaction between the rangeland's hydrology and vegetation states is vital for achieving long-term *** gain a better insight into the impact of restoration on surface runoff and erosion and its role in recovering the ecosystem functions,we used the Rangeland Hydrological and Erosion Model(RHEM)to simulate various vegetation *** research aims to understand the rangelands'water and sediment dynamics and the vegetation transition states of the ecosystem through evaluating the current(degraded)situation,assess the restoration approach on improving the degraded status(restored),and investigate the long-term sustainability of the restoration approach compared with historical rangeland conditions(baseline).several scenarios were developed with rangeland experts,local community representatives,and measurements at protected and restored areas to represent the rangeland *** found that restoration of the degraded Badia areas will decrease annual surface runoff from an average of 23.5 to 19.1 mm/year and soil erosion rate from 3.3 to 1.3 tons/*** time,restoration can bring back rangeland water and sediment dynamics closer towards the baseline conditions,which were 16.9 mm/year runoff rates and 0.85 ton/ha/year soil *** results indicate that restoration is a promising methodology to restore the degraded ecosystem and approximate the environment's historical hydrological regime.

关键词： soil measures runoff

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

spread of common native and invasive grasses and ruderal trees following anthropogenic disturbances in a tropical dry forest

引用

Ecological Processes 2017年第1期6卷 394-407页

作者： Xavier A.Jaime skip J.Van Bloem Frank H.Koch stacy A.C.Nelson Department of Ecosystem science and Management Texas A&M University2138 TAMUCollege StationTX 77843-2138USA Belle W.Baruch Institute of Coastal Ecology and forest science Clemson UniversityPO Box 596GeorgetownSC 29442USA usDA forest service Southern Research Station3041 East Cornwallis RoadResearch Triangle ParkNC 27709USA Center for Geospatial Analytics Department of Forestry and Environmental ResourcesNorth Carolina State UniversityRaleighNC 27695USA.

Introduction:A fundamental challenge to the integrity of tropical dry forest ecosystems is the invasion of nonnative grass *** grasses compete for resources and fuel anthropogenic *** 2012,a bulldozer from the Puerto Rico Electric Power Authority cleared a 570-m trail from a state road into a mature dry forest section of Guánica forest to control a *** monitored colonization by a non-native invasive grass(Megathyrsus maximus),a highly invasive tree(Leucaena leucocephala),and a native grass(uniola virgata),as well as natural regeneration,along the bulldozer *** determined whether bulldozing facilitated colonization by these species into the forest and the extent of ***:Distance from propagule source and temporal variations strongly influenced colonization by our three focal *** maximus invaded along the trail from source populations by the state *** establishment of new colonies of *** seedlings went as far as 570 m inside the forest(i.e.,at the end of the bulldozer trail),but we found most new colonies within 270 m of the *** leucocephala exhibited a similar spreading *** disturbance,uniola virgata was distributed widely across the forest,but the highest densities were found in areas near the latter portion(>401 m)of the bulldozer ***,the species formed new clumps along more than half of the trail(250 to 570 m),apparently colonizing from undisturbed patches ***:Bulldozing facilitated the invasion of non-native *** projected community assemblage will be more fire-prone than before since *** carries fire across the landscape better than ***,emphasizing the capacity of invasive plant colonization to alter local ecological processes after only a single wildfire and bulldoze *** results provide a valuable baseline for short-term vegetation response to anthropogenic disturbances in tropical semi-deciduous dry forests.

关键词： Tropical dry forest Grass invasions Bulldozing Wildfire Leucaena leucocephala Megathyrsus(Panicum)maximus uniola virgata

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Interrelationship of soil moisture and temperature to sylvatic plague cycle among prairie dogs in the Western united states

引用

Integrative Zoology 2021年第6期16卷 852-867页

作者： Cassandra D.PAuLING Deborah L.FINKE Deborah M.ANDERsON Department of Veterinary Pathobiology University of MissouriColumbiaMissouriUSA Division of Plant sciences University of MissouriColumbiaMissouriUSA

Plague,caused by Yersinia pestis,is a flea-borne disease that is endemic in areas throughout the world due to its successful maintenance in a sylvatic cycle,mainly in areas with temperate *** rodents are thought to play a key role in the enzootic maintenance as well as epizootic outbreaks of *** the united states,prairie dogs(Cynomys),rodents(Muridae),and ground squirrels(spermophilus)are susceptible to infection and are parasitized by fleas that transmit *** particular,prairie dogs can experience outbreaks that rapidly spread,which can lead to extirpation of colonies.A number of ecological parameters,including climate,are associated with these *** this study,we asked whether soil parameters,primarily moisture and temperature,are associated with outbreaks of plague in black-tailed prairie dogs and Gunnison’s prairie dogs in the Western united states,and at what depth these associations were *** collected publicly available county-level information on the occurrence of population declines or colony extirpation,while historical soil data was collected from sCAN and usCRN stations in counties and states where prairie dogs have been *** analysis suggests that soil moisture at lower depths correlates with colony die-offs,in addition to temperature near the surface,with key differences within the landscape ecology that impact the occurrence of ***,the model suggests that the burrow environment may play a significant role in the epizootic spread of disease amongst black-tailed and Gunnison’s prairie dogs.

关键词： plague prairie dogs soil moisture soil temperature sylvatic cycle Yersinia pestis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insights into the genus Diaporthe:phylogenetic species delimitation in the *** species complex

引用

Fungal Diversity 2014年第4期67卷 203-229页

作者： Dhanushka udayanga Lisa A.Castlebury Amy Y.Rossman Ekachai Chukeatirote Kevin D.Hyde Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201People’s Republic of China WorldAgroforestry Centre East and Central AsiaKunming 650201China Institute of Excellence in Fungal Research Mae Fah Luang UniversityChiang Rai 57100Thailand school of science Mae Fah Luang UniversityChiang Rai 57100Thailand systematic Mycology and Microbiology Laboratory United States Department of Agriculture-Agricultural Research ServiceBeltsvilleMD 20705USA

The genus Diaporthe comprises pathogenic,endophytic and saprobic species with both temperate and tropical *** diversification,phenotypic plasticity and extensive host associations have long complicated accurate identifications of species in this *** delimitation of the generic type species Diaporthe eres has been uncertain due to the lack of ex-type *** limits of *** and closely related species were evaluated using molecular phylogenetic analysis of eight genes including nuclear ribosomal internal transcribed spacer(ITs),partial sequences of actin(ACT),DNA-lyase(Apn2),translation elongation factor 1-α(EF1-α),beta-tubulin(TuB),calmodulin(CAL),60s ribosomal protein L37(FG1093)and histone-3(HIs).The occurrence of sequence heterogeneity of ITs within *** is observed,which complicates the analysis and may lead to overestimation of the species *** strict criteria of Genealogical Concordance Phylogenetic species Recognition(GCPsR)were applied to resolve species boundaries based on individual and combined analyses of other seven genes except the *** accept nine distinct phylogenetic species including Diaporthe alleghaniensis,***,***,***,***,***,***,*** and *** are designated for ***,***,***,***,*** and *** descriptions and illustrations are provided for these *** designed primers are introduced to amplify and sequence the Apn2(DNA-lyase)gene in *** on phylogenetic informativeness profiles,EF1-α,Apn2 and HIs genes are recognised as the best markers for defining species in the *** complex.

关键词： Diaporthaceae DNA-lyase Epitypification Gene discordance Generic type Molecular phylogeny New primers Phylogenetic informativeness speciation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Taxonomy of Pseudolagarobasidium(Polyporales,Basidiomycota)

引用

Fungal Diversity 2012年第4期55卷 155-169页

作者： Karen K.Nakasone Daniel L.Lindner Center for forest Mycology Research Northern Research StationU.S.Forest ServiceOne Gifford Pinchot DriveMadisonWI 53726-2398USA

Pseudolagarobasidium(Polyporales,Basidiomycota)is a small,monophyletic genus of crustose,wood-inhabiting fungi with spines and a saprobic,endophytic,or parasitic *** species are accepted in the genus including two new species,*** from Belize and *** from *** analysis of the internal transcribed spacer of the ribosomal RNA gene places *** in a monophyletic clade with *** and an undescribed foliar *** combinations proposed include *** for Irpex modestus Berk.,*** for Hydnum pronum Berk.&Broome which is an earlier name for ***,and *** for Radulodon venustus Hjortstam&*** colliculosum Berk.&Broome from sri Lanka is conspecific with *** species,sistotrema ochroleucum and Radulum concentricum are not accepted in *** is compared with Radulodon and similar genera.A key to the species of Pseudolagarobasidium is provided.

关键词： Pirex concentricum Pseudolagarobasidium acaciicola P.leguminicola Hydnum ayresii Microbinding hyphae

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ecohydrological processes and ecosystem services in the Anthropocene: a review

引用

Ecological Processes 2017年第1期6卷 364-372页

作者： Ge sun Dennis Hallema Heidi Asbjornsen Eastern forest Environmental Threat Assessment Center Southern Research StationU.S.Department of Agriculture Forest Service920 Main Campus Dr.Suite 300RaleighNC 27606USA Oak Ridge Institute for science and Education U.S.Department of EnergyOak RidgeTN 37830USA Institute for the study of Earth Oceansand SpaceUniversity of New HampshireDurhamNHUSA

The framework for ecosystem services has been increasingly used in integrated watershed ecosystem management practices that involve scientists,engineers,managers,and policy *** objective of this review is to explore the intimate connections between ecohydrological processes and water-related ecosystem services in human-dominated ecosystems in the *** synthesize current literature to illustrate the importance of understanding the ecohydrological processes for accurately quantifying ecosystem services under different environmental and socioeconomic settings and *** synthesis focuses on managed ecosystems that are dominated by humans and explores how ecological processes affect the tradeoffs and synergies of multiple ecosystem *** identify research gaps in studying ecological processes mainly including energy,carbon,water,and nutrient balances to better assess and quantify ecosystem services that are critical for sustaining natural resources for future *** better assess ecosystem services,future ecohydrological studies need to better account for the scaling effects of natural and anthropogenic stressors exerted on evapotranspiration and other water supply and demand *** studies should focus on the bidirectional interactions between hydrological functions and services and human actions to solve real world problems such as water shortages,ecological degradation,and climate change adaptation.

关键词： watershed services ecosystem

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

surface storm flow prediction on hillslopes based on topography and hydrologic connectivity

引用

Ecological Processes 2016年第1期5卷 153-165页

作者： Dennis W.Hallema Roger Mou.s. Ge sun steven G.McNulty INRA UMR LISAH Laboratoire d’etude des Interactions Sol-Agrosysteme-Hydrosysteme(INRAIRDMontpellier SupAgro)2 place Pierre Viala34060 Montpellier CEDEX 2France u.s.Department of Agriculture forest service Eastern Forest Environmental Threat Assessment CenterSouthern Research StationRaleighNC 27606USA u.s.Department of Energy Oak Ridge Institute for Science and EducationOak RidgeTN 37830USA

Background:Hillslopes provide critical watershed ecosystem services such as soil erosion control and storm flow regulation through collecting,storing,and releasing rain *** intense rainstorms,rainfall intensity and infiltration capacity on the hillslope control Hortonian runoff while the topographic attributes of the hillslope(e.g.,slope,aspect,curvature)and the channel network define the structural hydraulic connectivity that determines how rapidly excess water is *** paper discu.s.s literature on the link between topographic attributes and hydrologic connectivity and demonstrates how this link can be used to define a parsimonious model for predicting surface runoff during high intensity *** text:First,we provide a topographic characterization of the hillslope necessary to determine the structural hydrologic connectivity of surface flow based on existing ***,we demonstrate a hydrologic surface response model that routes the geomorphologic unit hydrograph(GIuH)through a spatial domain of representative elementary hillslopes reflecting the structural hydrologic *** attributes impact flow and travel time distributions by affecting gravitational acceleration of overland flow and channel,solar irradiance,flow deceleration by vegetation,and flow divergence/***:We show with an example where we apply the GIuH-based model to hypothetical hillslopes that the spatial organization of the channel network is critical in the flow and travel time distribution,and that topographic attributes are key in obtaining simple yet accurate representations of hydrologic *** GIuH models of surface runoff that use this hydrologic connectivity have the advantage of low data requirements,being scalable and applicable regardless of the spatial complexity of the hillslope,and have the potential to fundamentally improve flood forecasting tools used in the assessment of ecosystem servi

关键词： Hydrological processes Hydrologic connectivity storm flow Ecosystem services GIuH

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：