Landscape structures of different rural landscape connectivity in typical plateau karst regions: Taking the Houzhai River area of Anshun City, Guizhou Province as an example

Landscape connectivity is important for energy and material flow in ecosystems as well as for the survival of species. The landscape structure influences and reflects the degree of landscape connectivity. In order to study the coupling relationship between landscape structure and connectivity and reveal the succession relationship between its structure and connectivity in the typical karst plateau area. The study analyzed the typical area of Houzhai River in Puding County, Anshun City, Guizhou Province, according to the landscape pattern index and probability landscape connectivity index. The results show:(1) The landscape structure of the study area A is mainly characterized by large patches and uniform distribution. The main land is woodland and cultivated land, and the overall landscape is low fragmentation.(2) The landscape structure of the study area B is mainly characterized by the clustering of a certain type of land cover and the uneven distribution of the patches, for example, cultivated land. Other types of patches are scatteredly distributed, and the overall landscape is highly fragmented.(3) The study area A, B in 100, 500, 1000, 2000, 3000, 5 distance thresholds of landscape connectivity were 1.55, 1.99, 2.26, 2.49, 2.58 and 0.02, 0.10, 0.15, 0.19, 0.20, respectively. The average landscape connectivity is 2. 18 and 0. 13, respectively. Study Area A has a higher degree of landscape connectivity than B. Landscape pattern indicators can represent the landscape structure and probability landscape connectivity index calculates the landscape connectivity in the study area. The results of the study can provide a basis for ecological restoration of plateau karst regions and well-oriented rural development planning.

The corridor effect of metropolitan spatialextension and optimization of landscape structure—the case of Beijing

Because of the existence of gradient field of the urban center and the corridor effect. underthe drive of going merely after economic benefit, the city intrinsically has the trend of massive growth, and this will seriously destroy the urban reasonable landscape structure and the ecological equilibrium.By applying the theory of corridor effect. this paper studies the interactive process between artificialcorridors and natural corridors. At the same time, by studying the Beijing's spatial extension pattern in central urban area during different periods. this paper analyses the corridors extension volume.extension velocity and variant tendency of urban landscape on & directions. Moreover. this paperbrings forward the idea of incorporating the systen of natural corridors into the Beijing'smetropolitan planning, namely to form a star-shaped scattering-group pattern in which artificialcorridors and natural corridors are alternately distributed in order to effectively prevent built-up areafrom massive growth .

Landscape structure and land uese on county level in northeastern Yunnan Province of China——a case study of Huize County

Taking Huize County as an example, the paper analyzed the landscape structure(landscape element structure, landscape type structure, landscape spatial structure, landscape succession structure) and the relations between landscape structure and land use. It was pointed out that the agriculture should be developed in harmony with the landscape structure in the study area.

Spatial pattern analysis for quantification of landscape structure of Tadoba-Andhari Tiger Reserve,Central India

Landscape structure is often regarded as an important factor that governs the distribution and abundance of species. Therefore it is critical to understand the landscapes and their dynamics. Patterns of landscape elements strongly influence the ecological characteristics. This study was designed to document and map the current status of the tropi-cal dry deciduous forest of the Tadoba-Andhari Tiger Reserve （TATR）, Central India, （using IRS P6 LISS IV data） and to describe its landscape structure at three levels of organization viz. landscape, class, and patch. The study area was classified into 10 land cover classes that include 6 vegetation classes. The landscape structure was analyzed using FRAG-STATS using 12 set of indices. The TATR landscapes have a total of 2,307 patches with a mean patch size of 25.67 ha and patch density of 1.7 patches per km2. Amongst all land cover classes, mixed bamboo forest is dominant-it occupied maximum area （77.99%）-while riparian forest is least represented （0.32%）. Mixed forest has maximum number of patches among all vegetation classes. Results have shown that despite being dominant in the area, mixed bamboo forest has low patch density （0.25/100 ha）. Dominance of mixed bamboo forest is attributed to large patch sizes and not to the number of patches. This study has focussed on the approach of integrating satellite forest classification and forest inven-tory data for studying forest landscape patterns.

Landscape structure and bird's diversity in the rural areas of Taiwan

This study tries to discuss the relationship between landscape structure and organisms in the perspective of landscape architecture. The research hypotheses were then proposed as (1) there are relationships between landscape structure indexes and birds' diversity in the rural areas of Taiwan; (2) the relationships between landscape structure and birds' diversity will be different in different hierarchical levels. In order to increase the bird species, landscape planners could tries to increase the density of water bodies, but decrease the farms and human planted woods. Decrease the density of constructed and human planted grasslands. Increase the area of un-worked acres, natural grasslands, and the area of water bodies and circular the water bodies and natural forest. In order to increase birds' diversity, landscape planners could decrease the concentration of paved areas. Concentrate the human planted trees to increase the core areas of woodlands. Increase the area of natural grassland circular. In order to increase the total number of birds in the planning areas, landscape planners could scattered the paved areas and lengthen the constructed areas. Decreases the core region of the constructed areas. Increase the area of un-worked acres and water bodies. Decrease the disturbance of both the interior area of natural and human planted woodlands and try to increase the density of water bodies.;The analysis results showed that the small grain size indexes are more suitable for the rural areas of Taiwan to capture the influential factors of bird communities. The high fragmentation of land usages in Taiwan lessens the influences of the regional landscape pattern.

Additions of landscape metrics improve predictions of occurrence of species distribution models

Species distribution models are used to aid our understanding of the processes driving the spatial patterns of species’ habitats. This approach has received criticism, however, largely because it neglects landscape metrics. We examined the relative impacts of landscape predictors on the accuracy of habitat models by constructing distribution models at regional scales incorporating environmental variables (climate, topography, vegetation, and soil types) and secondary species occurrence data, and using them to predict the occurrence of 36 species in 15 forest fragments where we conducted rapid surveys. We then selected six landscape predictors at the landscape scale and ran general linear models of species presence/absence with either a single scale predictor (the probabilities of occurrence of the distribution models or landscape variables) or multiple scale predictors (distribution models?+?one landscape variable). Our results indicated that distribution models alone had poor predictive abilities but were improved when landscape predictors were added; the species responses were not, however, similar to the multiple scale predictors. Our study thus highlights the importance of considering landscape metrics to generate more accurate habitat suitability models.

Spatiotemporal Evolution and Influencing Factors of Landscape Ecological Vulnerability in the Three-River-Source National Park Region

The increasing impact of global warming and human activities has exacerbated the ecological environment in the Three-RiverSource National Park Region(TNPR). Understanding the temporal and spatial evolution of landscape ecological vulnerability(LEV)and its influencing factors are crucial to the implementation of environmental management. Here, we aimed to: 1) construct a LEV assessment model integrating landscape structure and function;2) analyze the temporal and spatial evolution of TNPR’s LEV from 1995to 2015;3) use geographic detectors to reveal the regional influence factors of TNPR’s LEV. The main findings were: 1) grasslands, water, and bare land are important landscapes of TNPR, accounting for 98.37% of the total area. During the study period, there were significant differences in the area of different landscapes;except for desert, shrub, and urban land, the other landscape areas showed a decreasing trend. 2) During the study period, the LEV of TNPR showed a downward trend;except for grasslands, the ecological vulnerability of the other landscapes decreased steadily. Furthermore, a pattern of conversion from high to low vulnerability grade was observed in the study area. In terms of spatial distribution, the LEV level shows a trend of high at both ends(east and west) and low in the middle.3) Overall, the impact of natural factors on the ecological vulnerability of the TNPR was significantly higher than that of human factors.In conclusion, our study provides a scientific basis for landscape structure optimization and the management of regional ecological vulnerability.

Landscapes—Structure, Functions, and Development Trends (On the Example of Landscapes of Georgia)

The article discusses the peculiarities of landscape geography development, types of landscape structure and their types, the essence of cultural landscape and its types, landscape functions and peculiarities of their definition, the main tasks and challenges of using and managing Georgian landscapes.

The influence of canopy-layer composition on understory plant diversity in southern temperate forests

Background： Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest functioning.Despite their importance, the influence of overstory-layer composition on understory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed forests.The aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversity in three forest types（monospecific deciduous Nothofagus pumilio（Np）, monospecific evergreen Nothofagus betuloides（Nb）, and mixed N.pumilio-N.betuloides（M） forests）, comparing also between two geographical locations（coast and mountain） to estimate differences at landscape level.Results： We recorded 46 plant species： 4 ferns, 12 monocots, and 30 dicots.Canopy-layer composition influences the herb-layer structure and diversity in two different ways： while mixed forests have greater similarity to evergreen forests in the understory structural features, deciduous and mixed were similar in terms of the specific composition of plant assemblage.Deciduous pure stands were the most diverse, meanwhile evergreen stands were least diverse.Lack of exclusive species of mixed forest could represent a transition where evergreen and deciduous communities meet and integrate.Moreover, landscape has a major influence on the structure, diversity and richness of understory vegetation of pure and mixed forests likely associated to the magnitude and frequency of natural disturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive species.Conclusions： Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous and pure evergreen understory plant species and different assemblages in coastal and mountain sites.Maintaining the mixture of canopy patch types within mixed stands will be important for conserving the natural patterns of understory plant composition in southern beech mixed forests.

Landscape characteristic aesthetic structure： Construction of urban landscape characteristic time-spatial pattern based on aesthetic subjects

The paper presents means and models of city-landscape characteristic structure construction on the aspect of landscape aesthetics subjects, which is called the landscape characteristic aesthetic structure and in short as LCAS. In this paper, the steps of LCAS research are as follows： Describes the concepts of the landscape characteristic aesthetic structure （LCAS）, and expounds the LCAS properties： systematic quality, temporal and spatial quality, and virtual existence. Learns from typology research methods, discusses the elements and types needed in a landscape characteristic aesthetic system, and constructs research method for LCAS pattern. As for the temporal dimension, the dynamic evolution and interaction expressed in LCAS between the ＂tradition＂ and ＂modernity＂ landscapes conflict. As for the spatial dimension, this paper explores the LCAS patterns in macroscopic scope of city group, the middle scope of single cities and the microcosmic scope of urban spaces with questionnaires and examples research.

The efect of landscape structure on the evolution of two alternative dispersal strategies

Background:Dispersal is an important event for most organisms at least once in their life cycle.The evolution of dispersal can be infuenced by local adaptation,landscape structure,and perceived temporal and spatial variation.The interaction between local adaptation,landscape heterogeneity,temporal variability and rules of dispersal may be more complex than previously assumed.Therefore,we sought to understand the infuence of emigration rules and landscape structure on emerging dispersal rates and traits.Here,we implemented an individual-based model(IBM)of trait evolution in scenarios characterized by diferent landscape structures and diferent degrees of spatial heterogeneity and global temporal variation.Individuals could evolve two traits coding for their environmental niche(position of niche optimum and niche width),and two traits determining nearest-neighbor dispersal:an individual emigrates with a probability defned by the frst trait(random emigration),but emigrates with certainty if the fertility expected in the patch of residence falls below a threshold specifed by the second trait(habitat-dependent emigration).Results:We note an interaction efect between dispersal strategy and spatial variance—lower emigration under habitat-dependent than under random emigration if spatial heterogeneity is low,but eventually a reversal of this ranking if heterogeneity becomes large.Landscapes with sharp transition of habitat attributes result in a high degree of spatial sorting,while fractal landscapes do not.Emigration rates are overall lowest,when spatial variation is highest.Conclusions:We conclude that emergent emigration rates are infuenced more by landscape structure and spatiotemporal heterogeneity than by the emigration strategy.With the ongoing land use change more research into this topic could help highlight the difculties species might face under the change from landscapes characterized by gradual transition zones to landscapes dominated by abrupt ecotones,the latter typical for agricultural and urban settings.

Land tenure and landscape change:a comparison of public-private lands in the southern High Plains

Introduction:Long-term drought in the southern Great Plains increases the vulnerability of coupled human-environment systems at a variety of scales.Developing better understandings of the dynamics at regional scales will become increasingly important as long-established land-use regimes break down in the face of climate change,resource depletion,and evolving governance.To demonstrate differential vulnerability during drought periods,this study hypothesized that observed increases in woody vegetation in grasslands would vary across land-tenure regimes.We argue that differences in State Trust Land governance,in part,lead to differential land management practices that contribute to landscape change.Methods:The study area encompasses adjacent counties,Cimarron County in Oklahoma and Union County in New Mexico,with similar climate variability and agricultural economies.We analyzed National Land Cover Database(NLCD)land-cover maps from 1992 and 2011 to assess changes in landscape composition and structure between 1992 and 2011.Results:During both years under consideration,each county in the study region,across various land-tenure regimes,was dominated by herbaceous vegetation.However,there were changes in both composition and structure across the whole study area,in particular losses of herbaceous vegetation and increases in woody vegetation.The greatest gains in woody vegetation occurred in State Trust Lands of Cimarron County.Overall,the data suggest a fragmentation of herbaceous vegetation and a coalescing of shrubland patches.Conclusions:Research about the influence of land tenure on land management decisions,specifically the role of State Trust Land leases in overgrazing,informs the broader context of drought management in the southern Great Plains.Recommendations include continued research to highlight the specific mechanisms of land-tenure governance that drive landscape change.

Urban landscape structure anatomy:Structure patterns and typology identification in the space-time of Setif City,Algeria

The definition of urban form and its elements raises a wide debate in urban morphology.This study presents a proposal to understand the structuring of the urban landscape of Setif City over 170 years(1848-2018)by abstracting its main elements into permanent structure(PSUL).It corresponds to the street network,more static to the change of the town plan,and flexible structure(FSul),more resilient to change and explains the superimpositions of morphological components(plot,building,and land use).This work aims to identify typological patterns of structures suggested in space-time through the inspection of the growth of the street network and the filling of morphological layers framed by the concept of urbanity.The methodology is based on syntactic(diachronic)morphogenetic analysis,with statistical analyses as unsupervised classification.Results indicate that PSUL presents an accumulation of microincrements produced with a similar degree of coherence in different urban fabrics,which explain the local patterns of street network structuring.The typology of FSul patterns indicates an unbalanced growth by the arrangement between morphological elements,resulting in a variation in the degree of urbanity.

How the “Folding Funnel” Depends on Size and Structure of Proteins?A View from the Scoring Function Perspective

It has been well accepted that the folding energy landscape may resemble a funnel according to the theory of protein folding. This theory of ＂folding funnel＂ has been extensively studied and thought to play an important role in guiding the sampling process of the protein folding and refinement in protein structure prediction. Here, we have investigated the relationship between the ＂funnel likeness＂ of protein folding and the size/structure of the proteins based on a set of non-homologous proteins we have recently evaluated using a statistical mechanicsbased scoring function ITScorePro. It was found that larger proteins that consist of more helix/sheet structures tend to have a higher score-Root Mean Square Deviation（RMSD） correlation（or a more funnel like energy landscape）.Another measurement in protein folding, Z-score, has also shown some correlation with the size of the proteins.As expected, proteins with a better ＂olding funnel likeness＂（or score-RMSD correlation） tend to have a betterpredicted conformation with a lower RMSD from their native structures. These findings can be extremely valuable for the development and improvement of sampling and scoring algorithms for protein structure prediction.