Comparison of structural diversity of tree-crop associations in Peripheral and Buffer zones of Gachabari Sal forest area,Bangladesh

The structural diversity of different tree-crop associations were studied at Gachabari Sal forest area of Madhupur Garh on Buffer and Peripheral Zone during 2006. The total density, basal area of trees in the Buffer and Peripheral Zone were 155.5 trees·hm^(-2), 795.4 trees·hm^(-2) and 3.9 m2·hm-2, 5.8 m^2·hm^(-2), respectively. No regeneration and natural trees were found in Peripheral Zone and the Zone is totally occupied by exotic species where the Buffer Zone comprised of both natural and exotic trees. The Peripheral Zone belonged to younger and smaller trees whereas the Buffer Zone belonged to mixture of smaller, taller, younger and mature trees simultaneously. For the practicing of different agroforestry systems both Zones have lost their original characters of Sal forest.

Comparison of structural diversity of tree-crop associations in Periph- eral and Buffer zones of Gachabari Sal forest area, Bangladesh

The original version of this article unfortunately contained three mistakes. （1） The spelling of the [A. Nishad＇] name was incorrect. The corrected spelling is given below.

Assessing Forest Cover Distribution, Species Diversity, and Richness of the Buffer Zone for Strategic Forest Management Planning for Nimule National Park, South Sudan

Natural forest ecosystems play an essential role in the conservation of biodiversity of many plants and animals by providing them with habitat and suitable environments. Studies have shown that biodiversity-protected areas reduce the loss and degradation of natural habitats to various wild species of plants. This study examined the forest resources in five subzones by conducting tree/shrub species inventory to be able to develop an effective forest management plan for the Buffer Zone Forest Reserve for the sustainable conservation of flora and fauna of Nimule National Park. This is with the view to identify the main tree and shrub species;assess the composition, distribution, and abundance of various tree/shrub species;to determine the species diversity as well as the richness of these areas in terms of growth and performance where DBH and heights of trees/shrubs in the circular sample plots were measured. The results revealed the overall mean DBH and H of 13.83 cm and 6.61 m respectively. The highest number of trees was obtained in subzone B followed by D, while the least were found in subzone A. The overall mean tree/shrub density was 0.83 tons/ha. The mean total basal area and volume per hectare were 3252.74 m2/ha and 46,540.82 m3/ha respectively. The overall species abundance and distribution indicate Combretum spp, Cedrella spp., Grewia mollis, Acacia Sieberiana, Ziziphus abysinica, and Acacia seyal were the most dominant species, with over 12 species richness at the deposition side of the River Nile, 13 species at the western side of the Nile, the Administration site shows only 7 species, the lowland of Mt. Gordon show over 14 different species, whereas over 10 species were found on the top of Mt. Gordon. The overall mean diversity indices and evenness of H’, D, and E depicted 2.507, 0.871, and 0.840 respectively. These results yielded are relatively moderate. Therefore, conservation efforts are very necessary to improve and maintain the quality of vegetation cover.

Spatial Variability of Microclimate Characteristics in Transition Zone of the Forest: A Case Study of Slătioara Secular Forest

Although the importance of forest margins in ecology is recognized, no study has been carried out in the Slătioara Secular Forest Reserve with reference to the variability of abiotic parameters along forest margins. With this study, we investigate to what extent microclimatic variables (air temperature—T_air, air humidity—H_air, soil temperature—T_soil, soil humidity—H_soil wind intensity (WIND) and photosynthetically active radiation intensity (PAR)) are correlated with the distance from the edge to the forest interior and the habitat type (forest interior, inner and outer edge and meadow) in the Slătioara Secular Forest Reserve. In order to measure these microenvironment variables we used the strip transect method, positioned perpendicular to the forest edge. Differences in the microenvironment variables considered in the analysis between the four habitat types were assessed using one-way ANOVA followed by Tukey-test post-hoc. To assess differences along transects, each of the six measurements went through a one-way ANOVA against distance to edge, followed by a Levene’s test for variances and finally a Tukey-test post-hoc. The results indicate that the values of microclimatic variables were significantly different in relation to the gradient of distance from the edge and to the habitat type (interior-exterior forest) and that edge habitats are significantly more susceptible to lower humidity, high winds, lower light and higher air temperatures than forest interior habitats. The ecological study of the edge areas in this reserve provides the basis for future research on forest dynamics and can guide conservation efforts to maintain the diversity and endemism of species in the Slătioara Secular Forest.

Entire Catchment and Buffer Zone Approaches to Modeling Linkage Between River Water Quality and Land Cover——A Case Study of Yamaguchi Prefecture,Japan

This study investigated the linkages between river water quality and land use in river catchments in Yama- guchi Prefecture, the western Japan, in order to examine the effect of land use changes of both entire catchment and buffer zone on river water quality. Dissolved Oxygen (DO), pH, Biological Oxygen Demand (BOD), Suspended Solids (SS), Escherichia coli, Total Nitrogen (TN) and Total Phosphorus (TP) were considered as river water quality indica- tors. Satellite images were applied to generating the land use map. Multiple regression model was applied to linking the changes in the river water quality with the land uses in both entire catchment area and buffer zone. The results in- dicate that the integrative application of land use data from the entire catchment and the buffer zone could give rise to more robust model to predict the concentrations of Suspended Solids (r2=0.88) and Total Nitrogen (r2=0.90), rather than models which separately considered land use data in catchment and buffer zone.

Research on Two Types of Buffer Zone Impact on Surrounding Office Space Environment in Winter in Cold Climate Zone—a Fieldwork in Architectural Design Institute Building of Tsinghua University,Beijing

Building buffer zone space is not only one of essential approaches for better mental quality of interior building space, but also an important factor that may influence interior thermal comfort and energy consumption. This study aims to analyze regulative advantages of buffer zone to the surrounding functional spaces. Based on a fieldwork test in a typical office building in cold climate zone in Beijing,China,the monitor data show interior physical performance in the Winter. The research selects two types of different buffer zones in the same building. One is a south-faced greenhouse which has large dimension with plenty of vegetation,and the other is a simple atrium in the middle of five floor building with mount of skylights. The factors and their influence to surrounding functional spaces and the whole building are found out from the comparisons of collected data by floor to floor monitor test on both buffer zones at the same time. The comparisons of two types of buffer zones conclude that the greenhouse is more effective to air quality regulation but not so clearly wellperformed to thermal buffering as expected due to the dominate active central heating in the Winter. This fieldwork test results for building performance can be helpful for both architects and engineers in the early phase of sustainable design.

Creek Proximity and Flora Effects on Arthropod Populations in Riparian Buffers in Washington State, USA

Due to federal, state, and local regulations pertaining to clean water and salmon recovery, stream health and water quality are major concerns in the Pacific Northwest of the United States. An integral component of most riparian rehabilitation efforts is the effective establishment of preferred vegetation. We conducted arthropod surveys in representative disturbed and rehabilitated riparian buffers directly adjacent to apple orchards and grape vineyards in the Lower Yakima Valley near Prosser, Benton County, Washington State USA. Objectives of the study were to determine whether densities of select predatory and pest taxa changed with distance from the waterway and to test whether densities differed among disturbed, rehabilitated, or pristine riparian buffers. The studies suggest that populations of some beneficial arthropods, including spiders and ground beetles, were higher in the presence of exotic flowering plant species. In the riparian environments surveyed, more native woody plant species were found adjacent to the waterway, and this apparent stability appears to have had a positive effect on beneficial arthropods. Concurrently, data indicated that some exotic, flowering species of plants may be preferred over native plant species as hosts to certain arthropod pests. These plants tend to persist in degraded riparian buffers and at the interface of riparian habitats and cultivated areas, whereas native plant species are predominant in pristine or properly maintained and rehabilitated buffers.

The Study of Spatial Distribution of Land Use in the Yellow River Delta in China

In this paper, Land at 8 OLI image data from 2013 to 2017 was interpreted by visual interpretation combined with supervised classification to extract the information of land use distribution in the Yellow River Delta in China. The characteristics of Land Use Cover Change (LUCC) in the past five years which were analyzed by land use spatial analysis method based on buffer zone were discussed to obtain the land use index trend of five land types in buffer zones at different distance. The land use transfer maps of 2013 and 2017 were made by using the geo-information mapping method. The spatial-temporal change rules and the development process of land use in the Yellow River Delta during the past five years were analyzed. According to the analysis results, the comprehensive index of land use degree in the study area was in the middle level. The land use transfer maps were mainly consisted of farmland and grassland. The change rate of bare land to vegetation was 20.21% and that of vegetation to bare land was 14.15%. This study can provide effective basis for the scientific management of land and rational guidance for planning in this area.

Research on Spatial Distribution Characteristics of Bars and Their Influence on Surrounding Residents:A Case Study of Hongling Area in Shenzhen

This paper took the bar space in Hongling area of Shenzhen as the research object,analyzed the relationship between the distribution of bars and urban commercial buildings,traffic stations,residential areas,hotels and guesthouses.It also analyzed the impact of bars on urban residents in terms of noise,crime and traffic congestion.The study found that the location of bars was closely related to urban commercial centers,traffic stations,residential areas,hotels and guesthouses,the occurrence of noise and criminal cases was also highly related to bars;and the distribution of bars had an impact on traffic congestion to a certain extent.

Spatial Distribution and Fluorescence Properties of Soil Dissolved Organic Carbon Across a Riparian Buffer Wetland in Chongming Island,China

The migration of soil dissolved organic carbon(DOC) from terrestrial to aquatic environments has important impacts on the adjacent water quality and the transport of organic and inorganic contaminants.However,few studies have investigated the sources and properties of DOC in riparian zones.A total of 34 soil samples were collected across four riparian buffer zones(Zones A-D) on Chongming Island,China.The vertical distributions of soil organic carbon(SOC) and DOC,fluorescence excitation-emission matrix(EEM) spectra of DOC and the optical indices,including fluorescence index(FI),index of recent autochthonous contribution(BIX),and humification index(HIX),were measured across the riparian environment to investigate the sources and fluorescence properties of DOC.The results showed that SOC stored in the surface soil(0-30 cm) accounted for 40%of the total soil profile SOC.The DOC accumulated in Zones A-C,which accounted for 5%of the SOC.The fluorescence EEM spectra of DOC showed that DOC contained humic-like and protein-like substances,which were mainly derived from recent plant debris by microbes.A large amount of humic-like substances were sorbed to minerals in the surface soil(0-30 cm).In addition,the riparian topography and soil physico-chemical properties(pH,EC and moisture) dictated the transformation and transport of DOC.The results suggested that EEMs could reveal the source of DOC in riparian soil systems,and that optical indices were complementary tools that revealed the characteristics of soil DOC and provided supplemental evidence about DOC sources.

Assessment of buffer zone for aquatic organisms in pesticide application

In pesticide applications,the buffer zone helps to protect water sources against pesticide contamination.In 2014,in the Adana province,the percentage of herbicides used was approximately 12%in corn,sunflower,soybean and cotton.To control the weeds,fifteen active ingredients(a.i.)were used in these crops in 2014.These a.i.were acetochlor,aclonifen,benfluralin,bromoxynil,clethodim,dicamba,fluazifop-p-butyl,foramsulfuron,linuron,mesotrione,nicosulfuron,oxyfluorfen,prometryn,trifluralin and tritosulfuron.The aim of this study was to assess the risk of these herbicides on aquatic organisms and estimate buffer zone distances for the above agricultural crops in herbicide application.Risk index(RI)values were calculated according to German Drift Model(GDM)and Dutch Drift Model(DDM).Consequently,buffer zone needs for herbicide application of five a.i.,namely acetochlor,benfluralin,linuron,prometryn,and trifluralin,were determined in this study.Results showed that acetochlor a.i.has the highest risk to aquatic organisms and needs a buffer zone distance of more than 57 meters in sunflower cultivation.It was assessed that buffer zone distances should be more than 1.32 m for linuron in soybean,3.5 m for benfluralin in sunflower,4.13 m for prometryn(1.5 kg a.i./hm^(2))in sunflower and 4.19 m for trifluralin in cotton and soybean,and 5.54 m for prometryn(2.0kg a.i./hm^(2))in cotton.There was no need for a buffer zone in corn.

A Bond Pricing Model with Credit Migration Risk:Different Upgrade and Downgrade Thresholds

In this paper, a new corporate bond pricing model with credit migration risk is proposed. This model sets different thresholds for the rising or falling of credit ratings, which forms a buffer zone that could reduce the frequency of credit rating changes. Mathematically, this model is a system of partial differential equations with overlapping area. The existence, uniqueness, regularity and asymptotic behavior of the solution are obtained. Furthermore, a numerical scheme and its stability, convergence and accuracy are discussed in detail. Calibration and analysis of the parameters are also suggested.

Impact analysis of expressway construction on ecological carrying capacity in the Three-River Headwater Region

The construction of expressways has a variety of impacts on the ecologically fragile and sensitive Three-River Headwater Region and causes changes in the structure and carrying capacity of the ecosystem. To assess the impact of expressway construction on the ecological carrying capacity of the regional natural system, net primary productivity(NPP)was used as the quantitative index to indicate the efficiency of the regional ecological environment to fix and transform photosynthesis products. In this study, trend analysis and buffer zone analysis were used to quantitatively analyze the spatial and temporal characteristics of NPP in the study area from 2006 to 2015 based on the MOD17A3/NPP dataset. In addition, the spatial-temporal effects of expressway and interchange construction on NPP in buffer zones were studied using GIS spatial analysis. The summarized results are as follows.(1) The multi-year average NPP in the study area is 137.9 gC/m^2,indicating a slight downward trend;spatially, the overall NPP shows a downward trend from east to west.(2) The impact of expressway construction on NPP in buffer zones will last for more than two years, generally presenting greater NPP further from the expressway.(3) After completion of the interchange, the NPP decreases significantly within its radiation radius;at a distance of 6 km, the NPP gradually stabilizes.(4) The influence law of expressway construction and interchange construction on NPP is approximately the same in the respective buffer zones.