Do aeolian deposits and sand encroachment intensity shape patterns of vegetation diversity and plant functional traits in desert pavements?

The effects of sand encroachment on composition,diversity,and functional patterns of vegetation in drylands are rarely studied,and yet addressing these aspects is important to deepen our understanding of the biodiversity conservation.This study aimed to investigate the effect of sand encroachment on plant functional biodiversity of desert pavements(gravel deserts)in the Sahara Desert of Algeria.Plants were sampled and analyzed in three desert pavements with different levels of sand encroachment(LSE)and quantity of aeolian deposits(low,LLSE;medium,MLSE;and high,HLSE).Within the sample-plot area(100 m^(2)),density of every plant species was identified and total vegetation cover was determined.Plant taxonomic and functional diversity were analyzed and compared between LSE.Result showed that 19 plant species in desert pavements were classified into 18 genera and 13 families.Asteraceae and Poaceae were the most important families.The species Anabasis articulata(Forssk)Moq.characterized LLSE desert pavements with 11 species,whereas Thymelaea microphylla Coss.&Durieu ex Meisn.and Calobota saharae(C&D)Boatwr.&van Wyk were dominant species of desert pavements with MLSE(14 species)and HLSE(10 species),respectively.The highest values of species richness and biodiversity were recorded in desert pavements with MLSE,while low values of these ecological parameters were obtained in desert pavements with HLSE.Desert pavements with LLSE were characterized with the highest values of species abundances.Plant communities were dominated by chamaephytes,anemochorous,arido-active,and competitive stress-tolerant plants.The increase in LSE along the gradient from LLSE to HLSE induced significant changes in plant community variables including decreases in plant density,plant rarity,lifeform composition,morphological type,and aridity adaptation.Desert pavements with HLSE favor the degradation of vegetation and trigger biodiversity erosion.

Modeling and Mapping Sand Encroachment Risk as an Aid for Urban Planning in the United Arab Emirates (UAE)

Sand encroachment into urban areas represents a high risk factor for transportation infrastructural and urban development in the United Arab Emirates. The UAE is located in one of the world’s largest arid regions with a strong prevalence of sand movement and encroachment into urban areas, particularly in the last few years. The objective of this research is to develop a land surface process platform that models sand movements and further generates an encroachment risk index map of potential encroachment risk areas season-wise in the UAE. To achieve this objective, this research used elevation and land cover maps generated from Lands at 8 Operational Land Imager (OLI) data which represent the topography of the study area coupled with meteorological information on wind speed, temperature and precipitation. Furthermore, the study considered the vegetation cover as a major contribution factor to reduce sand encroachment. Using developed sand movement model for this research, sand encroachment risk maps were generated to help urban planners in cities making informed decisions of future urban protection structures and transportation networks that mitigate the effects of sand dunes encroachments in the UAE. A major finding of this research results conclude that during the summer season encroachment risk reaches 30% higher compared to the winter season due to the extremely high temperature which leads to reduced vegetation in the country. Urban planning decision maker may consider the finding of this research for future infrastructural adjustments.

Tree encroachment into savannas alters soil microbiological and chemical properties facilitating forest expansion

Abstract Forests have been expanding over typical savanna sites for the past 3000 years in the Neotropics. Such invasion can produce a series of environmental modifications on typical savanna; however, it remains unclear how modifications in soil properties, caused by the encroachment of woody species, facilitate the expansion of forest ecosystems under dystrophic conditions. Here we examined chemical and microbiological changes associ- ated with tree encroachment in oxisols of a Neotropical Savanna at Assis Ecological Station, Southeastern Brazil. We predicted that tree encroachment caused by typical forest species would cause significant changes in the chemical and microbiological properties of savanna soils. Soils were sampled at Assis Ecological Station, from savanna sites differing in tree encroachment （typical, dense and forested savanna） caused by decades of fire exclusion. We analysed vegetation leaf area index and leaf litter volume deposited in the studied plots and chemical （pH,organic matter, P, K, Ca, Mg, A1, NO3-, NH4＋） and microbiological （microbial C biomass and dehydrogenase activity） properties of soils under distinct encroachment conditions. Most soil chemical properties did not change along the tree encroachment gradient; however, total P, soil organic matter, soil microbial C and dehydrogenase activity increased from typical savanna to forested savanna. The changes in soil organic matter and dehydrogenase activity were correlated with the values of leaf area index and litter volume along the encroachment gradient. Our results demonstrate that forest species can increase carbon and phosphorus supplies in tropical savanna soils.

Encroachment of the Buriganga River in Bangladesh

A survey on different aspects of Buriganga River encroachment was conducted in a 300 meter long encroached part of the river located in Dhaka, Bangladesh. A total of 100 respondents were surveyed and three Focus Group Discussions (FGDs) were arranged prior to the semi-structured questionnaire survey. It was observed that almost all of the respondents migrated to the study area. The majority of the respondents had better business opportunity (69.23%) as the cause of encroachment. Significant portions of the respondents occupying the encroached area were found to be landless (36.84%), small businessmen (31.58%) and people with political affluence (26.32%). Major portions (23.33%) of the encroached land were used for industrial development as well as housing and developmental projects. Negative health impact (40%) was found to be the main adverse effect of encroachment of the river. Other adverse effects included economic loss through obliteration of fisheries (35.71%), scarcity of clean water (32.14%), reduction of aesthetic value of the surroundings (25%) etc. For the protection of the river, the majority of the respondents opted for relocation of the industries (46.15%) and enforcement of strict rules and regulations (38.46%).

The Impact of Encroachment on the Distribution of Tree Species in Cross River National Park, Oban Division, Nigeria

Increasing human activities around protected area pinpoint to looming degradation and alteration of the component of such areas, especially where adequate measures are not taken to forestall encroachment. The Oban division of the Cross River National Park is one of the oldest rainforests and has been identified as a biodiversity hotspot. However, communities settling around the park have been involved in some economic activities for their livelihood. Resource utilization at the edge of the park may alter the components of the park such as species diversity. Therefore this study is geared towards assessing the impact of human encroachment and the concomitant impact on the distribution of species within the park. The study adopted participatory research methods which included Focus Group Discussion and participatory mapping as well as a plot based survey which involved the laying of sample plots within two zones of the park designated as areas bounded by cultivated land and areas bounded by fallow. Three 40 m × 40 m square plots are laid along a 320 meter transect measured from the boundary of the park at each buffer zone. The plots are separated by 100 m gap. From the result obtained, it is discovered that Musanga cercropoides dominates the outer plots of the cultivated zones and fallow zones comprising 20.2 and 21.5 percent respectively while Terminalia ivorensis dominates the middle and inner areas of the park. Moreover the composition of species decreases inward to the inner part of the park. Diversity index decreases in the order of 2.566 < 2.348 < 2.163 at the cultivated zones and 2.443 < 2.376 < 2.366 at the fallow zones. It is concluded that human activities close to the park alters the species composition of the park. Hence, it’s recommended that adequate alternatives livelihood and incentive be provided to support zone communities to reduce their dependents on the edge of the park.

Manufacturer encroachment and carbon reduction decisions considering cap-and-trade policy and retailer investment

Low-carbon regulation and market competition present new opportunities and challenges for supply chain firms,emphasizing the significance of carbon reduction and channel encroachment in enhancing competitiveness.This study formulates various game models to evaluate manufacturers’encroachment strategies(with or without encroachment)under different conditions of low-carbon investment by retailers.It investigates the operational decisions and carbon abatement strategies of firms under various scenarios.The findings reveal that encroachment elevates unit abatement levels but decreases wholesale prices and retailer profits when unit encroachment costs are below certain thresholds.In contrast,the manufacturer consistently benefits from channel encroachment.Retailer-initiated low-carbon investments can motivate manufacturers to reduce emissions.A lower carbon price potentially offers financial advantages to retailer engaging in such investments.Additionally,the likelihood of reduced environmental damage postchannel encroachment,compared to preprofessional encroachment,increases when the retailer invests in low-carbon initiatives.The retailer’s profit is inversely related to the carbon price,and a higher carbon price can strengthen the incentive effect of low-carbon investment on the manufacturer’s abatement endeavors.

Gas Exchange Rates of Texas Persimmon (Diospyros texana) in Central Texas Woodlands

Diospyros texana (Texas persimmon) is a secondary species in most Juniperus ashei/Quercus fusiformis woodlands in central Texas. It has high density, but plants are mostly in the community understory. Light response curves at ambient and elevated levels of CO2 and temperature were measured for D. texana. The Anet (photosynthetic rate) increased significantly as both light level and CO2 levels increased but not temperature. The Amax (maximum photosynthetic rate) of D. texana in full sun at elevated levels of CO2 was increased for all treatments. Stomatal conductance increased with levels of CO2 but only if the interaction was removed from the model. Intercellular levels of CO2 increased with both temperature and CO2 treatments as did water use efficiency (WUE). Furthermore, light saturation (Lsat) increased with CO2 treatments and light compensation (Lcp) increased with temperature. The dark respiration (Rd) increased with both temperature and CO2 treatments. Markov population models suggested D. texana populations would remain ecologically similar in the future. However, sub-canopy light levels and herbivory should be considered when examining population projections. For example, Juniperus ashei juveniles are not recruited into any canopy unless there are high light levels. Herbivory reduces the success of Quercus juveniles from reaching the canopy. These factors do not seem to be a problem for D. texana juveniles which would allow them to reach the canopy without need of a high light gap and are not prevented by herbivory. Thus, Juniperus/Quercus woodlands will change in the future to woodlands with D. texana a more common species.

Mechanisms,monitoring and modeling of shrub encroachment into grassland:a review

Shrub encroachment into arid and semi-arid grasslands has elicited extensive research attention worldwide under the background of climate change and increasing anthropogenic activities.Shrub encroachment may considerably impact local ecosystems and economies,including the conversion of the structure and function of ecosystems,the shift in ambient conditions,and the weakness of local stock farming capacity.This article reviews recent research progresses on the shrub encroachment process and mechanism,shrub identification and dynamic monitoring using remote sensing,and modeling and simulation of the shrub encroachment process and dynamics.These studies can help to evaluate the ecological effect of shrub encroachment,and thus,practically manage and recover the ecological environment of degraded areas.However,the lack of effective measures and data for monitoring shrub encroachment at a large spatial scale severely limits research on the mechanism,modeling,and simulation of shrub encroachment,and the shrub encroachment stages can hardly be quantitatively defined,resulting in insufficient analysis and simulation of shrub encroachment for different spatiotemporal scales and stages shift.Improvement in remote sensingbased shrub encroachment dynamic monitoring might be crucial for analyzing and understanding the process and mechanism of shrub encroachment,and multi-disciplinary and multi-partnerships are required in the shrub encroachment studies.

Woody plant encroachment may decrease plant carbon storage in grasslands under future drier conditions

Aims Woody plants are widely distributed in various grassland types along the altitudinal/climatic gradients in Xinjiang,China.Considering previously reported change in carbon(C)storage following woody plant encroachment in grasslands and the mediating effect of climate on this change,we predicted that a positive effect of woody plants on plant C storage in semiarid grasslands may revert to a negative effect in arid grasslands.We first investigated the spatial variation of aboveground C(AGC)and belowground C(BGC)storage among grassland types and then tested our prediction.Methods We measured the living AGC storage,litter C(LC)and BGC storage of plants in two physiognomic types,wooded grasslands(aboveground biomass of woody plants at least 50%)and pure grasslands without woody plants in six grassland types representing a gradient form semiarid to arid conditions across Xinjiang.Important Findings Living AGC,LC,BGC and total plant C storage increased from desert to mountain meadows.These increases could also be explained by increasing mean annual precipitation(MAP)or decreasing mean annual temperature(MAT),suggesting that grassland types indeed represented an aridity gradient.Woody plants had an effect on the plant C storage both in size and in distribution relative to pure grasslands.The direction and strength of the effect of woody plants varied with grassland types due to the mediating effect of the climate,with wetter conditions promoting a positive effect of woody plants.Woody plants increased vegetation-level AGC through their high AGC relative to herbaceous plants.However,more negative effects of woody plants on herbaceous plants with increasing aridity led to a weaker increase in the living AGC in arid desert,steppe desert and desert steppe than in the less arid other grassland types.Under greater aridity(lower MAP and higher MAT),woody plants allocated less biomass to roots and had lower BGC and had a more negative impact on herbaceous plant production,thereby reducing vegetation-level BGC in the desert,steppe desert and desert steppe.In sum,this resulted in a negative effect of woody plants on total plant C storage in the most arid grasslands in Xinjiang.As a consequence,we predict that woody plant encroachment may decrease rather than increase C storage in grasslands under future drier conditions.

The effects of medical insurance and patients’ preference on manufacturer encroachment in a pharmaceutical supply chain

With the development of e-commerce,manufacturers have opportunities to sell products to consumers through direct channels in addition to independent retailers.Although manufacturers’encroachment upon the retailing market of traditional goods has been extensively studied,there is a lack of research on manufacturers’encroachment in a pharmaceutical supply chain.This paper analyzes a pharmaceutical manufacturer encroachment strategy by taking into account the distinctive features of drugs,in which drug expenses are covered by medical insurance only in the physical channel and patients'channel preference is also considered.We find that under certain circumstances,the manufacturer encroachment may lead to a win-win outcome for both the manufacturer and the retailer,contradicting the conventional wisdom that the manufacturer's encroachment into retail space is detrimental to the independent retailer.Additionally,the manufacturer is more likely to encroach when the incurred extra cost is sufficiently small,the perceived quality of the drug selling through the direct channel is sufficiently high and the out-of-pocket percentage cost of the drug selling in the physical channel is high.We further study the impact of manufacturer encroachment on social welfare and find that the introduction of encroachment decreases the social welfare when patients'perceived quality of the drug obtained through the online store is low and improves the social welfare when the perceived quality exceeds a certain threshold.

In-house or Outsourcing R&D?Manufacturer Technology Strategy in the Presence of Market Follower Encroachment

Facing the threat of market follower encroachment,this paper constructs game theoretical models based on different channel structures and market structures,investigates following manufacturer's encroachment strategy and technology strategies,and discusses the impact of following manufacturer's strategy on quality decisions.The results show that encroachment always improves consumer surplus by slashing prices when leading manufacturer adopts in-house R&D(IRD);otherwise,it results in lower consumer surplus with mild competition if leading manufacturer is at a technological disadvantage.Furthermore,the technology strategies of following manufacturer are related to their R&D capabilities.The superior one is outsourcing R&D(ORD)for the manufacturers when their R&D capability is weak,otherwise,IRD is optimal.In a word,the leading manufacturer always prefers IRD under certain conditions,while the following manufacturer always prefers ORD.In addition,encroachment restrains quality innovative motivation under fixed or quality-sensitive R&D costs,but can improve quality level when consumers have a higher reference dependency for quality;meanwhile,the following manufacturer adopting ORD is always beneficial to quality improvement.

Plant physiological changes along an encroachment gradient: an assessment of US Mid-Atlantic serpentine barrens

Aims Serpentine barrens of the Mid-Atlantic United States are globally rare,grass-dominated ecosystems thought to exclude C3 spe-cies and characterized by unique soil composition.However,like many grassland ecosystems globally,these sites are presently facing encroachment by surrounding forest.In this ecosystem,the tendril climbing vine,Smilax rotundifolia,forms dense thickets around bar-rens that typically precede forest encroachment.While numerous factors speculatively initiate and promote encroachment in these systems,few studies have examined photosynthetic responses of serpentine grasses to changes in resource availability initiated by encroachers or physiological ability of encroaching S.rotundifolia to colonize high-light barren environments.We sought to under-stand both environmental and physiological dynamics of encroach-ment along an irradiance gradient in these systems.Methods At three serpentine barren sites in southeastern Pennsylvania,physiological responses of the native grasses Sorghastrum nutans and Schizachyrium scoparium to increased shading by S.rotundi-folia were examined.Additionally,the physiological performance of S.rotundifolia in the forest understory was compared to that in sunlit barrens environments.Light-saturated photosynthesis(A_(sat)),stomatal conductance(g_(s)),instantaneous transpiration efficiency(ITE),maximum efficiency of photosystem II(F_(v)/F_(m)),midday leaf water potential(ψ_(leaf))and specific leaf area(SLA)were measured for all species over the course of the 2014 growing season.Two-way analyses of variance were used to assess changes in these param-eters across growing environments,as well as seasonally for each species.Multiple regression analyses were also performed to inves-tigate the influence of vapor pressure deficit(D)and leaf tempera-ture(T_(leaf))on A_(sat) and ITE.Important Findings Light-saturated photosynthesis was significantly greater in S.rotun-difolia growing in sun than in the shade(P<0.001)and early in the season(P=0.012).Sun S.rotundifolia had up to 27%greater A_(sat) than shaded plants.Even with reducedψleaf in the barrens,S.rotundifolia maintained high g_(s) though A_(sat) was limited by high D later in the growing season.These data are in agreement with recent research suggesting that plants are not subject to water limi-tation in Mid-Atlantic barrens.Unexpectedly,shaded grasses at the encroachment interface did not exhibit any significant reduc-tion in A_(sat).Declines in grass photosynthesis do not likely occur until S.rotundifolia rhizomes transition into monotypic thickets,completely excluding grasses.Encroachment by S.rotundifolia appears to be primarily facilitated by its ability to capitalize on light resources early on in the summer growing season,when environ-mental conditions are less stressful.

Dynamic Changes of the Bush Encroachment in Low Altitude Area of Ethiopia

Bush encroachment is widely distributed in arid and semi-arid regions, and it has a serious impact on livestock production, especially in Africa where livestock is a primary source for the livelihoods of many people. In this study, methods of supervised classification and decision tree classification, and indexes of a land use change significance index（Ci） and a single land use dynamic degree, were applied to remote sensing imagery of Ethiopia for 1986–2016. The results show the dynamic characteristics of grassland bush encroachment in low altitude areas（pastures 1500 m above sea level） of Ethiopia in the 30 year period studied. The results revealed several interesting features of this phenomenon.（1） The area of bush encroachment showed an increasing trend, with a maximum of 3.74×10^3 km^2 in 2003, which represented 68.97% of the total area, and declined slightly from 2003~2016.（2） Among classification types, the area of severe shrub grassland was the largest, accounting for 28.36–49.10% of the total area, while the area of moderate bush encroachment accounted for 9.77–16.68%, and slight bush encroachment accounted for 5.52–7.57%.（3） The expansion rate of shrubby grassland was 0.74% for the 30 year period, while the average annual expansion rate was 2.16% for the 8 years from 1995–2003.（4） Forest land and grassland were the two main land use types of shrub grassland transformation in low altitude areas and bush encroachment changed large amounts of forest land into grassland due to shrub grassland management. The results of this study provide basic data for revealing the impacts of development processes on subsequent bush encroachment and can inform better management for the sustainable development of grasslands in low altitude systems.

VTOL UAVs for Forest Monitoring and Management via Remote Sensing: A Case Study in Khao Yai National Park, Thailand

The utilization of UAVs (Unmanned Aerial Vehicles) has experienced a remarkable upsurge in various industries, including forestry. Their capacity to expeditiously and effectively cover large tracts of land has resulted in their widespread adoption as a valuable forest management and monitoring tool. The versatility of UAVs extends to their capability to perform quick and efficient surveys of large areas, inventory of tree species, and monitoring of forest health. This research paper reports on the successful utilization of VTOL (Vertical Takeoff and Landing) UAV that was designed and built at the IESSD (Institute of Earth Science and Sustainable Development) located in the AAA (Asia Aviation Academy) at KMITL (King Mongkut’s Institute of Technology Ladkrabang) Prince of Chumphon Campus, Thailand. The VTOL UAV is employed for resource and environmental missions, as well as forest monitoring by using remote sensing technology. VTOL UAVs are used for aerial surveillance to conduct air photography, data collection, and processing for resource and environmental missions. This research paper presents a comprehensive analysis of the areas at risk of deforestation and forest encroachment in a particular region of Khao Yai National Park in Thailand, highlighting the potential for the resulting photographs to inform evidence-based decision-making and facilitate sustainable forest management practices. This study offers recommendations to develop VTOL UAVs remote sensing capabilities and mitigate deforestation and forest encroachment in Khao Yai National Park.

Supplier Encroachment and Quality Disclosure Strategy in an E-supply Chain with Blockchain Technology

This paper explores quality disclosure strategy in an e-supply chain including a supplier and an e-retailer driven by blockchain technology(BT),wherein the supplier possesses private quality information and has the option to encroach on the end market.We investigate the no-encroachment and encroachment scenarios under the three quality disclosure strategies(i.e.,non-disclosure strategy,voluntary disclosure strategy and BT-supported disclosure strategy).The impact of supplier encroachment and firms’preference for disclosure strategies are examined.The analysis shows that regardless of the strategy chosen,encroachment always benefits the supplier but,under certain conditions,benefits the e-retailer.Interestingly,with no-encroachment,both the supplier and the e-retailer have the same preference for disclosure strategies.With encroachment,however,the supplier prefers the voluntary disclosure strategy when both the quality variability and direct selling cost are small,and BT’s operation cost is relatively large;otherwise,he prefers the BT-supported disclosure strategy.For the e-retailer,she always prefers both the voluntary and BT-supported disclosure strategies.Additionally,it is observed that the BT-supported disclosure strategy emerges as optimal for both the supplier and the e-retailer when faced with significant quality variability,regardless of encroachment.Encroachment and adopting BT can generate more consumer surplus under certain conditions.Finally,we extend the basic model by considering simultaneous quantity decision and find that keying findings are robustness.Afterwards,management insights are covered and given.

Shrubs proliferated within a six-year exclosure in a temperate grassland—Spatiotemporal relationships between vegetation and soil variables

Overgrazing has been considered one of the maj or causes that trigger shrub encroachment of grassland. Proliferation of shrubs in grassland is recognized as an important indicator of grassland degradation and desertification. In China, various conservation measures, including enclosures to reduce livestock grazing, have been taken to reverse the trend of grassland desertification, yet shrubs have been reported to increase in the grasslands over the past decades. In late 2007, we set up a 400-m-by-50-m exclosure in a long-term overgrazed temperate grassland in Inner Mongolia, with the ob- jective to quantify the spatiotemporal relationship between vegetation dynamics, soil variables, and grazing exclusion. Soil moisture was continuously monitored within the exclosure, and cover and aboveground biomass of the shrubs were measured inside the exclosure in 2007, 2009, 2010, 2012, and 2013, and outside the exclosure in 2012 and 2013. We found the average shrub cover and biomass significantly increased in the six years by 103 % and 120%, respectively. The result supported the hypothesis that releasing grazing pressure following long-term overgrazing tends to trigger shrub invasion into grassland. Our results, limited to a single gradient, suggest that any conservation measures with quick release of overgrazing pressure by enclosure or other similar means might do just the opposite to accelerate shrub en- croachment in grassland. The changes in vegetation cover and biomass were regressed on the temporal average of the soil moisture content by means of the generalized least square technique to quantify the effect of the spatial autocor- relation. The result indicates that the grass cover and biomass significantly increased with the top, but decreased with the bottom layer soil moisture. The shrub cover and biomass, on the other hand, decreased with the top, but increased with bottom soil moisture, although the regression coefficients for the shrubs were not statistically significant. Hence this study supports the two-layered soil model which assumes grasses and shrubs use belowground resources in dif- ferent depths.

Consumer Choice, Firm Performance and Channel Coordination in a Dual-Channel Distribution System

The expanding role of the Internet in consumer purchasing activities has created substantial new opportunities accessing to end-consumers. More and more manufacturers are beginning to sell products to potential consumers directly online while continuing to sell through the traditional brick-and-mortar retailers, a phenomenon leading to intense channel competition and conflicts. Using game theory, this research examines the effect of market segments, consumer choice and the acceptance of direct online channels on firm performance and the whole system’s profit. The analysis indicates that the addition of direct online channel does not necessarily harm the incumbent retailers. A win-win zone is proposed, in which both the manufacturer and the retailer benefit from the encroachment.

Influence of Tree Density on Vegetation Composition and Soil Chemical Properties in Savanna Rangeland of Eastern Cape, South Africa

The proliferation of woody species alters the vegetation structure, leading to loss of rangeland productivity. It aimed to assess the influence of tree density on vegetation and soil chemical properties at three levels of encroachment;open, moderate and dense. Each level of encroachment was replicated 3 times, a 5000 m2 plot was marked per replicate. Four belt transects 200 m2 were placed per plot. Woody species within each belt transect per replicate were identified and recorded to evaluate woody species composition. Grass species composition was assessed using a step point method. Soil was sampled per replicate and analysed for chemical properties. Results showed that 71% of grasses were increasers and 29% decreasers. Digitaria eriantha and Eragrostis obtusa were the most dominant species. Vachellia karoo and Aloe ferox were the most dominant woody species. The dense had high nitrogen (1.48%) compared to the moderate (0.23%) and the open (0.17%). Increaser species, soil carbon, soil pH increased with the increase of tree density. It was concluded that the replacement of highly palatable grasses with inferior ones was due to improper rangeland management practices. It was recommended that land users form rangeland management associations and set up conservation agreements for proper management of resources.

Plant Diversity and Vegetation Structure in Encroached and Non-encroached Areas of Borana Rangelands： The Case of Hallona and Medhacho Pastoralist Associations

The Borana rangelands are important areas of cattle production in Ethiopia. However, these rangelands are threatened by the increasing changes in the natural vegetation from grass and forbs dominated into unpalatable bushy woody vegetation resulting in the loss of some of the highly desirable grass species. This study was conducted to assess the impacts of bush encroachment on the biodiversity, structure and cover of the native vegetation in bush encroached and non-encroached sites. Vegetation data were collected from both sites by laying quadrate plots along transects using a systematic sampling method. According to the results, higher number of species was recorded in the non-encroached sites than that in the encroached sites. The diversity indices for the non-encroached and the encroached sites were 3.16 and 2.67, respectively. The abundance and cover analysis indicated that there was high density and cover of herbaceous species in the non-encroached site. There was a significantly higher density of woody species cover in the encroached site. Generally, the bush encroachment in the Borana rangelands has hampered the diversity of the native vegetation, particularly the grasses and forbs and reduced the ground cover, exposing large parts of the rangelands for soil erosion and other degradation process.

Impact of Controlling Shareholder Equity Pledge on Corporate Value

As an innovative financing behavior,equity pledge breaks the limit of traditional financing,and broadens the financing channels of companies and major shareholders.This paper comprehensively considers the impact of controlling shareholder equity pledge on corporate value from three research perspectives.The main conclusions are as follows:(1)When the equity pledge is not considered,the cash flow rights and voting rights of the company owned by the controlling shareholder are positively correlated with corporate value.That is,this presents incentive effect,but the existence of the separation of the two powers brings the second type of agency problem and reduces corporate value.(2)When considering the equity pledge,the controlling shareholder’s equity pledge may weaken the incentive effect and strengthen the encroachment effect which causing a reduction of corporate value.(3)Based on the accounting point of view,the controlling shareholder’s equity pledge is negatively correlated with the corporate performance,while the concentration of ownership dilutes this negative effect.(4)The balance of equity weakens the negative effect of the controlling shareholder’s equity pledge on corporate value,thereby reduces the negative impact of the equity pledge.