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.

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.

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.

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.