Spatial variation and prediction of forest biomass in a heterogeneous landscape

Large areas assessments of forest bioinass distribution are a challenge in heterogeneous landscapes, where variations in tree growth and species composition occur over short distances. In this study, we use statistical and geospatial modeling on densely sample.d forest biomass data to analyze the relative importance of ecological and physiographic variables as determinants of spatial variation of forest biomass in the environmentally heterogeneous region of the Big Sur, California. We estimated biomass in 280 forest Plots （one plot per 2.85 km2） and meas- ured an array of ecological （vegetation community type, distance to edge, amount of surrounding non-forest vegetation, soil properties, fire history） and physiographic drivers （elevation, potential soil moisture and solar radiation, proximity to the coast） of tree growth at each plot location. Our geostatistical analyses revealed that biomass distribution is spatially structured and autocorrelated up to 3.1 kin. Regression tree （RT） models showed that both physiographic and ecological factors influenced bio- mass distribution. Across randomly selected sample densities （sample size 112 to 280）, ecological effects of vegetation community type and distance to forest edge, and physiographic effects of elevation, potential soil moisture and solar radiation were the most consistent predictors of biomass. Topographic moisture index and potential solar radiation had apositive effect on biomass, indicating the importance of topographically- mediated energy and moisture on plant growth and biomass accumula- tion. RT model explained 35% of the variation in biomass and spatially autocorrelated variation were retained in regession residuals. Regression kriging model, developed from RT combined with kriging of regression residuals, was used to map biomass across the Big Sur. This study dem- onstrates how statistical and geospatial modeling can be used to dis- criminate the relative importance of physiographic and ecologic effects on forest biomass and develop spatial models to predict and map biomass distribution across a heterogeneous landscape.

Parameterization of Heat Fluxes at Heterogeneous Surfaces by Integrating Satellite Measurements with Surface Layer and Atmospheric Boundary Layer Observations

The regional heat flux exchange between heterogeneous landscapes and the nearby surface layer （SL） is a key issue in the study of land-atmosphere interactions over arid areas such as the Heihe River basin in northwestern China and in high elevation areas such as the Tibetan Plateau. Based on analysis of the land surface heterogeneity and its effects on the overlying air flow, the use of SL observations, atmospheric boundary layer （ABL） observations, and satellite remote sensing （RS） measurements along with three parameterization methodologies （here, termed as the RS, tile, and blending approaches） have been proposed to estimate the surface heat flux densities over heterogeneous landscapes. The tile and blending approaches have also been implemented during HEIhe basin Field Experiment （HEIFE）, the Coordinated Enhanced Observing Period （CEOP） Asia-Australia Monsoon Project on the Tibetan Plateau （CAMP/Tibet）, the Arid Environment Comprehensive Monitoring Plan ＇95 （AECMP＇95）, and the DunHuang Experiment （DHEX）. The results showed that these two proposed parameterization methodologies can be accurately used over heterogeneous land surfaces.

Multifunctional landscapes—perspectives for the future

New methods in landscape ecology to study the link between landscape heterogeneity and landscape functionality are needed. Heterogeneity is a basic characteristic of landscape, and landscape function is the capacity to change the structural heterogeneity of a landscape system. In most developed countries the industrialisation of agriculture has in general resulted in a change of agricultural landscapes from a small-grained heterogeneous pattern towards more monotonous and monofunctional landscapes. During the 1990's this trends seems to have changed due to a diversification of rural land use and new trends in urbanisation. Weather these phases of landscape development should be expected in developing countries is a totally open question. Dealing with the study of multifunctionality of landscapes it is proposed to distinguish between ecological functionality of landscape ecosystems, functionality pertaining to land use and social functionality. Further, the relation between function, space and scale is important by the determination of spatial and time segregation as well as spatial and time integration of multifunctionality in landscapes.

Spatio-temporal Variation of Landscape Heterogeneity under Influence of Human Activities in Xiamen City of China in Recent Decade

Xiamen is an economically competitive and highly urbanized city along the coastal area of Fujian Province, China. The research on spatio-temporal variation of landscape heterogeneity under the influence of human activities is of great importance to the further study on the relationship of landscape pattern and ecological process. It is also crucial to the discovery of spatial variation and intensity distribution of human activities. The research analyzed the intensity of human impacts and the spatial variation features and dynamics of landscape patterns by introducing statistical theories and approaches. We analyzed spatio-temporal variation of landscape heterogeneity using the geostatistical techniques, such as semivariogram and Kriging interpolation.Results show that there is a higher correlation between landscape heterogeneity indexes and human impact index. Both the indexes show a moderate spatial autocorrelation as well as an obvious characteristic of anisotropy. From 1998 to 2008, the spatial differentiation of the changes in the intensity of human activities and the changes in landscape heterogeneity shows that the landscape patterns in Xiamen are closely related with the urban land utilization methods, the condition of traffic and geographical location and the physical geographical condition such as the terrain and the ecological environment. The process of urbanization has a significant impact on the urban landscape pattern.

Analysis on sensitivity and landscape ecological spatial structure of site resources

This article establishes a set of indicators and standards for landscape ecological sensitivity analysis of site resources by using the theories and approaches of landscape ecology. It uses landscape diversity index(H), evenness(E), natural degree(N), contrast degree(C) to study spatial structure and landscape heterogeneity of site resources and thus provides a qualitative-quantitative evaluation method for land planning and management of small, medium scale areas. The analysis of Yantian District, Shenzhen of China showed that Wutong Mountain belonged to high landscape ecological sensitivity area, Sanzhoutian Reservoir and Shangping Reservoir were medium landscape sensitivity area and high ecological sensitivity area; Dameisha and Xiaomeisha belonged to medium sensitivity area caused by the decline of natural ecological areas. Shatoujiao, Yantian Pier belonged to low sensitivity area but urban landscape ecological development had reshaped and influenced their landscape ecological roles in a great extent. Suggestions on planning, protection goals and development intensity of each site or district were raised.

Advances in Terrestrial Mammal Movement Ecology:An Overview

As a research field which is blooming quickly in recent years,movement ecology has been a worldwide concern and interest.However,movement ecology is so comprehensive and complicated that many articles only focus on few aspects or species.As tracking technologies and methods of movement data analysis develop,the abundance of movement data becomes available for demonstrating more scientific facts about animal movement.This article is aimed to summarize the advances of terrestrial mammal movement ecology in the past years to show its critical and potential research fields,as well as trying to ascertain direction of these advances.

Assessing forest fragmentation in north-western Himalaya:a case study from Ranikhet forest range,Uttarakhand,India

The northwestern Himalaya harbors high levels of biodiversity due to its unique topography, climatic conditions and heterogeneity. Forest fragmentation is one of the major threats causing a decline in biodiversity in the Himalayan region. We assesses forest fragmentation and changes in land use land cover（LULC） patterns using multi-temporal satellite data over a time span of four decades（1976–2013）. Fragmentation analysis using the Landscape Fragmentation Tool（LFT） reveals a decrease in core and edge areas by 14 and 2.3 %, respectively; while an increase in non-forest, patch area and perforation area by 2.1, 0.4, and 14 %, respectively. The LULC dynamics show that the areas under dense forest and scrub forest have decreased by 2.8 % and 1.9 %, respectively; and there is an increase in open forest, crop land and fallow land area by 2.6, 1.7 and 2.1 %, respectively. The quantification of landscape heterogeneity is undertaken with the help of landscape metrics computed using FRAGSTATS at class and landscape level, showing signs of increased fragmentation. Our study provides baseline database that can support the future biodiversity conservation and sustainable forest management initiatives.

Assessing the bird guild patterns in heterogeneous land use types around Jammu,Jammu and Kashmir,India

Land-use sprawl in the Himalayas has caused the conversion of natural habitat into human-modified habitats,thus degrading ecosystem health.Adaptation of birds to changing physical environment can be well understood by analyzing their habitat preferences,and foraging dynamics explored to a limited extent in the Himalayan region,as yet.To achieve a comprehensive understanding of avian guild structure,we used multivariate statistical techniques to classify bird species according to their similarities in foraging patterns and habitat preferences.Observations based on habitat and diet affinities accounted for rich avian diversity with a total of 208 bird species(about 15%of country’s avifauna)recorded from six different sites during 1 year survey.Unweighted pair-group average cluster analysis performed on the families revealed ten feeding and fifteen habitat guilds among 63 bird families observed.Subtropical forests harbored more species followed by urban forests and agricultural landscapes.Insectivorous and omnivorous outnumbered other feeding guilds in the study area.Bird assemblages were richer in protected areas and semidisturbed landscapes and did not show significant variation between the seasons.Results of the study revealed that different functional groups of birds behaved differently,primarily induced by choice of food.The site heterogeneity favored avifaunal persistence by providing favorable foraging,roosting,and nesting opportunities to birds.Composition of avian guilds indicated level of intactness and ecological integrity of ecosystems studied.This outcome thus sets the background for long-term analysis of bird-habitat relationship and their foraging dynamics.The study has the relevance for decision-makers to integrate avian guild structure as an essential ingredient in formulating conservation strategies.

Simple assessment of farmland soil phosphorus loss risk at county scale with high landscape heterogeneity

In order to improve the existing phosphorus index assessment methods,using the interactive evaluation index(IEI)as an auxiliary variable,the geographically weighted regression(GWR)was adopted as prediction means.A method of regional soil phosphorus risk assessment was constructed by modifying phosphorus index model(MPIM).The GWR-IEI method more accurately predicted available phosphorus(AP)and soil organic matter(SOM),and the prediction precision and goodness of fit were high.Compared with the ordinary least square(OLS)method,the relative improvement of the root mean squared errors(RMSE)with the GWR-IEI method reached 28.95%for available phosphorus predicted,while that of SOM was 21.24%.The phosphorus loss risk of most of the study area(95.29%)was moderate to low.The areas featuring an extremely high phosphorus loss accounted for merely 0.33%of the total research area.Phosphorus loss depends on the effects of many factors.Areas which have strong source or transfer factors are not necessarily high-risk areas for phosphorus loss.Only the co-occurrence of transfer and source factors leads to high risk and greater potential for phosphorus loss.The GWR-IEI-MPIM method accurately reflected the degree of risk for phosphorus at the regional scale,which provides a valuable reference for risk assessment of phosphorus.

Does landscape context affect pollinationrelated functional diversity and richness of understory flowers in forest fragments of Atlantic Rainforest in southeastern Brazil?

Background:How landscape modifications affect functional diversity of floral characteristics pertinent to pollinators is poorly known.Flowers possess functional traits that sometimes coevolved with pollinators,crucial for the maintenance of both pollinator and plant communities.We evaluated how richness and functional diversity of available understory flowers respond to forest cover and landscape heterogeneity in a multiscale analysis.Plants in bloom were sampled from 25 landscapes in the understory of Atlantic Forest fragments in Brazil.Species were classified into functional groups regarding flower characteristics relevant to pollination.Landscape heterogeneity and forest cover were measured in buffers ranging from 200 to 2000 m from sampling units and their correlation with plant richness and functional diversity was assessed using generalized linear models and further model selection through Akaike’s second-order information criterion.Results:Plants’richness and functional diversity were affected negatively by forest cover.The former responded to forest cover at a regional scale while the latter responded at a local scale.Higher landscape heterogeneity increased richness and functional diversity.Conclusions:Our results showed that forest cover and landscape heterogeneity are important to support biodiversity related to pollination,mostly due to the availability of diversified resources and nesting sites associated to different land-uses for pollinators and flowering plant communities.These findings should highlight,along with forest cover,landscape heterogeneity as an environmental management priority in rural tropical areas for mitigating the loss of plant biodiversity and enhancing ecosystem functioning.

Immunological effects of nano-enabled hyperthermia for solid tumors: opportunity and challenge

Compared to conventional hyperthermia that is limited by low selectivity and severe side effects,nano-enabled hyperthermia yields great potentials to tackle these limitations for cancer treatment.Another major advance is the observation of immunological responses associated with nano-enabled hyperthermia,which introduces a new avenue,allowing a potential paradigm shift from the acutely effective and cytotoxicity-centric response to the next-phase discovery,i.e.,long-lasting and/or systemic anti-tumor immunity.This perspective first discusses the temperature-gradient and the spatially-structured immunological landscape in solid tumors receiving nano-enabled hyperthermia.This includes the discussion about underlying mechanism such as immunogenic cell death,which initiates a profound immunological chain reaction.In order to propagate the immune activation as a viable therapeutic principle,we further discussed the tumor type-specific complexity in the immunological tumor microenvironment,including the creative design of nano-enabled combination therapy to synergize with nano-enabled hyperthermia.

Using a simulation analysis to evaluate the impact of crop mapping error on crop area estimation from stratified sampling

To analyze the efficiency of area estimations(i.e.estimation accuracy and variation of estimation)impacted by crop mapping error,we simulated error at eight levels for thematic maps using a stratified sampling estimation methodology.The results show that the estimation efficiency is influenced by the combination of the sample size and the error level.Evaluating the trade-offs between sample size and error level showed that reducing the crop mapping error level provides the most benefit(i.e.higher estimation efficiency).Further,sampling performance differed based on the heterogeneity of the crop area.The results demonstrated that the influence of increasing the error level on estimation efficiency is more detrimental in heterogeneous areas than in homogeneous ones.Therefore,to obtain higher estimation efficiency,a larger sample size and lower error level or both are needed,especially in heterogeneous areas.We suggest that existing land-cover maps should first be used to determine the heterogeneity of the area.The appropriate sample size for these areas then can be determined according to all three factors:heterogeneity,expected estimation efficiency,and sampling budget.Overall,extending our understanding of the impacts of crop mapping error is necessary for decision making to improve our ability to effectively estimate crop area.