Spatial Structure and Development of Tourism Resources based on Point Pattern Analysis: A Case Study in Hainan Island, China

Tourism resources are the basic materials of tourism development, and they also provide the support for regional tourism spatial competition. The development of tourism depends on the degree to which tourism resources are utilized, and it is of great guiding significance for their development and utilization to study their spatial structure. Based on a large sample of data on tourism resources, and starting from the characteristics of multi-type,multi-level and multi-combination, this paper puts forward a framework and method for analyzing the spatial structure of tourism resources. Taking Hainan Island as an example, this paper describes the spatial structure of tourism resources in Hainan Island by using the method of point pattern analysis, identifies the tourism resource development zones, and puts forward some suggestions for the development of tourism resources. The results are as follows:(1) The characteristic scale of the spatial structure of tourism resources in Hainan Island is 30.5 km, and there are significant differences in the distributions of all kinds of tourism resources.(2) Through the spatial structure map of tourism resources, the tourism resource development zones are identified, including three tourist central city levels, “one horizontal and three vertical” tourist belts and four tourist combination areas.(3) By combing the distribution of tourism resources and the development zones in Hainan Island, the cross-border characteristics of the tourism resources and development zones are obvious. In order to give full play to the spatial combination and superposition effect of tourism resources, a change from a single isolated development mode to the overall combined development between regions is suggested. On the provincial scale, it is relatively accurate to describe the spatial structure of tourism resources for point data with a large sample size. However, the method of point pattern analysis can not only accurately describe the spatial structure of tourism resources, but it can also provide reference for other types of regional spatial analyses. The research results provide a scientific basis for the spatial planning of regional tourism resources and have practical significance for the development of regional tourism.

Point pattern analysis of different age-classes of Larix principis-rupprechtii in Luya Mountain Reserve,Shanxi Province,China

Larix principis-rupprechtii forest is an important vegetation formation and has a large distribution area in Luya Mountain Reserve,China.Spatial pattern analysis on individual trees in different age-classes of Larix principis-rupprechtii was made in this paper.Here,we employed the technique of point pattern analysis,which could analyze pat-terns under all scales along a gradient.It was based on spatial mapped points of individual distribution.The results of this study showed that the densities of the five age-classes varied in the order:age-class 3>age-class 4>age-class 5>age-class 2>age-class 1.Although age-classes 1 and 2 have much fewer individuals than other three age-classes do,the popula-tion was stable at present.However,it would be necessary to take some measures for improving population regeneration for a long-time view.The individuals of all age-classes focused on clumping distribution in space;however,their distribution pattern varied with the change of scale.This mainly depended on biological features of Larix principis-rupprechtii and forest environments,but it also meant that the scale was an important factor in controlling spatial distribution pattern of tree individuals.The feature of clumping distribution became more significant with the increase of age.The relationships between individuals in different age-classes were almost all significantly correlated with each other.These associations became more significant within the older age-classes.This suggested that the individuals of different age-classes were interdistributed,by which the population could get benefits in resource utilization.The technique of point pattern analysis is effective and easy to be used in species pattern study.Its results are more closer to the reality,especially for community structure.

Population structure and spatial pattern analysis of Quercus aquifolioides on Sejila Mountain,Tibet,China

Understanding population structure provides basic ecological data related to species and ecosystems.Our objective was to understand the mechanisms involved in the maintenance of Quercus aquifolioides populations.Using a 1 ha permanent sample plot data for Q.aquifolioides on Sejila Mountain,Tibet Autonomous Region(Tibet),China,we analyzed the population structure of Q.aquifolioides by combining data for diameter class,static life table and survival curve.Simultaneously,the spatial distribution of Q.aquifolioides was studied using Ripley’s L Function in point pattern analysis.The results showed:(1) Individuals in Q.aquifolioides populations were mainly aggregated in the youngest age classes,that accounted for94.3% of the individuals; the older age classes had much smaller populations.Although the youngest age classes(ClassesⅠ and Ⅱ) had fewer individuals than Class Ⅲ,the total number of individuals in classes Ⅰ and Ⅱ was also greater than in classes Ⅳ to Ⅸ.In terms of tree height,fewsaplings,more medium-sized saplings and few large-sized trees were found.The diameter class structure of Q.aquifolioides populations formed an atypical ‘pyramid’type; the population was expanding,but growth was limited,tending toward a stable population.(2) Mortality of Q.aquifolioides increased continuously with age; life expectancy decreased over time,and the survivorship curve was close to a Deevey I curve.(3) The spatial distribution pattern of Q.aquifolioides varied widely across different developmental stages.Saplings and medium-sized tree showed aggregated distributions at the scales of 0–33 m and 0–29 m,respectively.The aggregation intensities of saplings and medium-sized trees at small scales were significantly stronger than that of large-sized trees.However,large-sized trees showed a random distribution at most scales.(4) No correlation was observed among saplings,medium-and large-sized trees at small scales,while a significant and negative association was observed as the scale increased.Strong competition was found among saplings,medium-and large-sized trees,while no significant association was observed between medium-and largesized trees at all scales.Biotic interactions and local ecological characteristics influenced the spatial distribution pattern of Q.aquifolioides populations most strongly.

Spatial pattern analysis and associations of different growth stages of populations of Abies georgei var.smithii in Southeast Tibet,China

Abies georgei var.smithii is an important plant species in Southeast Tibet,China.It has high ecological value in terms of biodiversity protection,as well as soil and water conservation.We analyzed the spatial pattern and associations of A.georgei var.smithii populations at different growth stages by using Ripley's L function for point pattern analysis.The diameter structure was a nearly reverse 'J' shape.The amount of saplings and medium-sized trees accounts for a large part of the entire population,suggesting a high regeneration rate and an expanding population.In the transition from saplings to medium trees or to large trees,saplings show a significant aggregation distribution at small scales,while medium trees and large trees show a random distribution.There are significant inverse associations between saplings and medium trees and large trees at small scales,while there are no obvious associations between medium trees and large trees.The natural regeneration was affected by interspecific competition,and it was also affected by intraspecific competition.The joint effects of biological characteristics and environmental factors contribute to the spatial distribution pattern and associations of this A.georgei var.sm ithii population.

Spatial patterns of Picea crassifolia driven by environmental heterogeneity and intraspecifi c interactions

Research on the spatial patterns of tree populations is critical for understanding the structure and dynamic processes of forests.However,little is known about how the underlying drivers shape these patterns and species interactions in forest systems.In this study,spatial point pattern analysis investigated the combined eff ects of intraspecifi c interactions and environmental heterogeneity on the spatial structure and internal maintenance mechanisms of Picea crassifolia in the Qilian Mountain National Nature Reserve,China.Data were obtained from a 10.2-ha dynamic monitoring plot(DMP)and sixteen 0.04-ha elevation gradient plots(EGPs).Under complete spatial randomness,both mature trees and saplings in the DMP demonstratedlarge-scale aggregation with negative correlations.In EGPs,saplings were clustered in small mesoscales,mature trees were randomly distributed,and the interactions of saplingstrees at all elevations were not correlated.By eliminating the interference of environmental heterogeneity through the inhomogeneous Poisson process,saplings in the DMP and EGPs were clustered in small scales and trees randomly distributed.Intraspecifi c associations were negatively correlated,in the DMP and at low elevations,and no correlations in high elevations of EGPs.In the vertical scale,saplings showed a small-scale aggregation pattern with increase in elevation,and the aggregation degree fi rst decreased and then increased.The interactions of saplings-trees and saplings–saplings showed inhibitions at small scales,with the degree of inhibition gradually decreasing.Spatial patterns and associations of adults–adults did not change signifi-cantly.The results revealed that intraspecifi c interactions and environmental heterogeneity regulated the spatial patterns of P.crassifolia at small and large scales,respectively.Environmental heterogeneity might be the most decisive factor aff ecting the spatial patterns of saplings,while trees were more aff ected by intraspecifi c interactions.Moreover,competition between trees in this area could be more common than facilitation for the growth and development of individuals.

Spatio-Temporal Change of Dispersal Areas of Greater Kudu (Tragelaphus strepsiceros) in Lake Bogoria Landscape, Kenya

Decline in wildlife populations is manifest globally, regionally and locally. A wildlife decline of 68% has been reported in Kenya’s rangelands with Baringo County experiencing more than 85% wildlife loss in the last four decades. Greater Kudu (Tragelaphus strepsiceros) is endemic to Lake Bogoria landscape in Baringo County and constitutes a major tourist attraction for the region necessitating use of its photo on the County’s logo and thus a flagship species. Tourism plays a central role in Baringo County’s economy and is a major source of potential growth and employment creation. The study was carried out to assess spatio-temporal change of dispersal areas of Greater Kudu (GK) in Lake Bogoria landscape in the last four years for enhanced adaptive management and improved livelihoods. GK population distribution primary data collected in December 2022 and secondary data acquired from Lake Bogoria National Game Reserve (LBNGR) for 2019 and 2020 were digitized using in a Geographic Information System (GIS). Measures of dispersion and point pattern analysis (PPA) were used to analyze dispersal of GK population using GIS. Spatio-temporal change of GK dispersal in LBNR was evident thus the null hypothesis was rejected. It is recommended that anthropogenic activities contributing to GK’s habitat degradation be curbed by providing alternative livelihood sources and promoting community adoption of sustainable technologies for improved livelihoods.

Effects of grazing disturbance of spatial distribution pattern and interspecies relationship of two desert shrubs

Grazing significantly affects the distribution,growth,and productivity of shrubs.In this study,we evalu-ated the effects of grazing disturbance on the spatial distri-bution patterns and interspecific relationships of two desert shrubs,Ammopiptanthus mongolicus and Sarcozygium xan-thoxylon.Three types of grazing conditions were considered,including enclosed area(EA),seasonal rotational grazing area(SRGA),and grazing area(GA)(100 m×100 m),in the West Ordos Nature Reserve of Inner Mongolia,China.The results showed that A.mongolicus and S.xanthoxylon populations were uniformly distributed at a small scale,and the distribution in EA and SRGA became gradually ran-dom.In GA,A.mongolicus population showed aggregated distribution but S.xanthoxylon population showed random distribution at a small scale. Moreover, both A. mongolicus and S. xanthoxylon populations at the 5-7 m scale showed random distribution. At the small and intermediate scales, the two species showed positive interspecific relationships of GA. However, no interspecific relationship was noted between the two species in EA and SRGA. A significant positive relationship (P < 0.01) was noted between the two species at 2-9 m and a negative relationship (P < 0.01) at 13-17 m scales in GA. Positive relationship (P < 0.01) was noted between the two species at 6-13 m scales and a sig-nificant negative relationship (P < 0.01) at 14-24 m scales in SRGA. The two species of desert shrubs showed posi-tive interspecific relationships at the small scale, and they showed negative relationships as the interspecific compe-tition intensified in the presence of grazing disturbance. When the grazing intensity exceeds a certain threshold, the interspecific relationships become weak. Therefore, moder-ate grazing would facilitate interspecific competition and species succession, whereas excessive grazing would disrupt natural competition causing desertification ultimately.

Spatial analysis and structure of a cross-timber stand in the TallGrass Prairie Preserve (Pawhuska, Oklahoma)

I analyzed the spatial distribution and structure of trees in a cross timber forest in the Tallgrass Prairie Preserve （Pawhuska, Oklahoma, USA）. I mapped and measured diameter of all stems, saplings （〉1.5 m tall） and dead trees in a 4-ha plot. The stand was dominated by Quercus stellata and Q. marilandica. In total, I mapped 7,636 trees, consisting of 6,785 Q. stellata, 846 Q. marilandica, 2 Celtis occidentalis, 1 Fraxinus pensilvanica and 2 Prunus americana. For saplings, I mapped 54 Q. stellata and 21 Q. marilandica. The size class distribution of the two dominant species did not differ. The dominant mortality class was “standing dead”, while I only found saplings less than 2 m tall. The spatial distribution of the species indicated segregation in the use of the environment, generating a clumped univariate distribution of stems of the same species within radii of 30 m, but repulsion outside 30 m. This segregation can be explained by the different ecological requirements of each species.

Regeneration Characteristics and Spatial Pattern of <i>Platycladus orientalis</i>in Mount Tai, China

Platycladus orientalis is one of the main tree species in Mount Tai, and its sustainable development is of great significance to the protection and development of the forest ecological environment of Mount Tai. In this study, a representative sample plot of Platycladus orientalis with a size of 30 m * 20 m was selected on Mount Tai. The growth and distribution of the parent trees and seedlings of Platycladus orientalis were investigated in the sample plots. The results showed that both the mother cypress trees and seedlings inside the plot present an aggregated distribution pattern within a certain scale, which conforms to the distribution of most natural communities;and the mother cypress can promote seedlings within a certain scale. Although Platycladus orientalis has good natural regeneration ability, it is difficult to succeed in understory regeneration solely relying on natural fertility, and it is not conducive to the long-term stable development of forest stands. Therefore, the thinning of Platycladus orientalis and the adjustment of the forest stand structure and artificial promotion of natural regeneration can not only reduce operating costs, but also conform to the idea of forest near-natural management and maintain sustainable forest development.

Spatial distributions of tropical tree species in northern Vietnam under environmentally variable site conditions

Ecological interactions of species and thus their spatial pat- terns may differ between homogeneous and heterogeneous forests. To account for this, techniques of point pattern analysis were implemented on mapped locations of tree individuals from two 1-ha tropicalforest plots in Vietnam. We analyzed the effect of environmental heterogeneity on tree distributions; spatial distribution patterns of dominant species; inter-specific associations; and conspecific associations between life stages. Our analyses showed that： environmental conditions were homo- geneous at plot 1 but heterogeneous at plot 2; in both plots, all six domi- nant species were aggregated at various scales up to 30 m, and tree spe- cies were aggregated at larger scales in the homogeneous site than in the heterogeneous site; attraction between pairs of species was remarkably higher at the homogeneous site while negative associations were more frequent in the heterogeneous site; some species, H. kurzii, T. ilicifolia （homogeneous plot） and D. sylvatica, S. wightianum （heterogeneous plot） showed a lack of early life-stage individuals near conspecific adults. Moreover, additional clustering of young individuals was independent from conspecific adults, except D. sylvatica in both sites. These findings are consistent with the Janzen-ConneU hypothesis. Overall, habitat het- erogeneity influences spatial patterns and inter-specific associations of the tree species and evidences of self-thinning are shown in most species.

Conspecific negative density dependence in American beech

Background： One of the most important drivers of forest biodiversity is conspecific negative density dependence（CNDD）, a reduction in performance when conspecific densities are high. While the majority of CNDD research has focused on tropical forests, evidence is mounting that CNDD may also play an important role in temperate forests.To further explore the potential reach of this phenomenon, we investigated CNDD in American beech（Fagus grandifolia）in a mature mid-Atlantic forest.Methods： We used bivariate point pattern analyses to examine spatial relationships between large beech trees and conspecific saplings, and we also contrasted these patterns with comparable patterns for heterospecifics. In addition, to address the possibility of dispersal limitation and the associated effects on spatial patterns, we analyzed seedling density as a function of adult conspecific abundance.Results： We found that beech saplings were more repel ed from large conspecifics than large heterospecifics, despite the fact that beech seedling density was positively correlated with beech basal area. However, saplings of other canopy tree species were also repel ed from adult beech trees, suggesting a general suppressive effect. Nonetheless, the discrepancy between beech seedling and sapling densities beneath adult conspecifics suggests that beech seedling survival rates were reduced in vicinity of conspecific adults.Conclusions： Regardless of the extent to which beech inhibits heterospecific trees, a negative effect on conspecific recruits may be critical for biodiversity maintenance. Without this conspecific suppression, a dense layer of shade-tolerant beech saplings could form beneath adult beech trees. If this were to occur, beech would have a substantial head-start fol owing canopy disturbance, and this late-successional species could potential y dominate a stand in perpetuity,through repeated disturbance cycles.

Changes in forest structure, species diversity and spatial pattern following hurricane disturbance in a Piedmont North Carolina forest, USA

Aims Large hurricanes have profound impacts on temperate forests,but owing to their infrequent nature these effects have rarely been examined in detail.In 1996,Hurricane Fran significantly damaged many long-term tree census plots in the Duke Forest on the North Carolina Piedmont,thereby providing an exceptional opportunity to examine pre-and post-hurricane forest compositional trajectories.Our goal was to examine immediate,short-term(0–4 years)and longer term(;5 year)hurricane-induced structural,spatial and compositional changes in the tree population(stem d.b.h>1 cm)in the context of our detailed,long-term knowledge of the dynamics of these forests.Methods We surveyed stem damage and tree mortality in 34 long-term permanent plots(ca.70-year record;404–1012 m^(2))and 7 large mapped tree stands(ca.20-year record;5250–65000 m^(2))representing both transition-phase,even-aged pine stands and uneven-aged upland hardwood forests.We employed three types of damage measures to quantify stand-level damage severity:percentage of stems damaged,percentage of basal area lost and a‘stand-level damage index’.Second-order spatial analysis(Ripley’s K-function)was used to investigate patterns in tree mortality.Important findings Our study found hurricane effects on the structural attributes of Piedmont forests to be variable and patchy.Changes in tree species composition,however,were modest.Uprooting was the major damage type for the overstory trees[diameter at breast height(d.b.h.)>10 cm]apparently due to the exposure of the crowns to high wind combined with heavy rainfall prior to and during the storm.Saplings,juvenile trees and small trees(1–10 cm d.b.h.)of the understory and midstory were mainly damaged by being pinned or bent by their damaged large neighbors.Hurricane-induced tree mortality varied weakly among species,was positively correlated with pre-hurricane tree size and remained up to 2-fold higher than pre-hurricane background mortality 5 years after the hurricane.Spatial point pattern analysis revealed a patchy distribution of tree mortality during the hurricane sampling interval.Hurricane Fran resulted in a dramatic increase in average gap size from ca.400 m^(2) pre-hurricane to ca 1100 m^(2) after the hurricane,whereas maximum gap sizes reached 18–34 times larger than the pre-hurricane levels.

Patterns of grassland invasions by trees: insights from demographic and genetic spatial analyses

Aims Woody invasions into grasslands have increased globally due to changing land use,climate and introduced woody species,but spatial processes generating and sustaining these invasions are not well understood.To gain insight into the patterns of spread of tree populations within grasslands,and to propose a full spatial analytical toolbox for studying native and non-native woody spe-cies spread when long-term data are not available,we tested if 50 years of grassland invasion in Western Carpathians by Norway spruce(Picea abies Karst.)proceeded by one of the two tradi-tionally competing hypotheses of species spread:(i)by frontier expansion,or(ii)by advanced groups established ahead of the population frontier.We also tested whether the pattern of invasion changed over time.Methods We analyzed the spatial demographic and genetic patterns of a Norway spruce population invading a Western Carpathian grass-land using ripley’s L(t)and genetic kinship coefficients(Fij).We mapped and genotyped spruce trees across the invasion front(from the invasion leading edge to fully colonized grassland near the source population)using three demographic classes(adults,juve-niles and seedlings)to approximate the temporal aspects of the invasion.We studied how the spatial patterns of invasion by indi-vidual demographic classes and their genetic kinship varied among adjacent plots established at different distances from the source population(ranging from 0 to 160 m,in 40-m distance increments).Important Findings Juveniles were positively genetically related to adults on fine scales(<4 m),suggesting that adults within the grassland acted as a seed source and accelerated early invasion.However,adults did not act as nucleation centers for the formation of advanced juvenile groups.Instead,geneti-cally unrelated juveniles formed groups independently of adults.These groups were small and separate at the leading edge but they increased in size and graded into a continuous zone near the source population.Thus,juvenile recruitment occurred as a frontier expansion near the source population and as advanced groups controlled by environmental variation at the leading edge.unlike juveniles,seedlings were clustered on all scales across the invasion front and formed groups around adult crowns at the invasion leading edge.The bulk of seedling establishment occurred at intermediate distances from the source population,indepen-dently from the adults,suggesting that the invasion front continued to expand as a frontier,gradually coalescing with the advanced groups at the leading edge.Thus,the grassland invasion was driven by a gradual frontier expansion of the original population during the first 50 years,with advanced groups enhancing but not driving the invasion process.Frontier expansion appeared more important as a mechanism of woody species spread early in the invasion process in this study,while advanced groups may play a larger role over longer temporal scales.

Spatial associations of tree species in a subtropical evergreen broad-leaved forest

Aims The spatial segregation hypothesis and the low-frequency hypothesis are two important proposed mechanisms that delay or prevent competitive exclusion in ecosystems.Because tree species interact with their neighbors,the importance of these potential processes can be investigated by analyzing the spatial structures of tree species.Methods The distribution of the adults of 27 common tree species in a fully mapped 5-ha subtropical forest plot in Baishanzu,eastern China,was analyzed to investigate the community-level intra-and interspecific spatial association patterns.We first tested for the overall spatial pattern in the 5-to 40-m neighborhoods and classified first-order bivariate associations with a diametric scheme based on Ripley’s K and nearest-neighbor statistic(G-function).Then heterogeneous Poisson null models were used to distinguish second-order interactions from overall spatial associations(including first-order effects).Finally,we analyzed correlations between the existence of species interactions and some attributes of the species involved.Important Findings Partial overlap and segregation increased with scale,whereas mixing decreased.Nearly 70%of the species pairs occurred less than expected at random,and only 3.4%of the species pairs were well mixed;11.0%of all species pairs showed significant small-scale interactions,which was a greater frequency than expected by chance if species are abundant or prefer the same habitat,but less frequent than expected if species are highly aggregated.This suggests that both spatial segregation and low frequency of species facilitate species coexistence by reducing the opportunity that trees of two species encounter each other.The study also revealed that positive interactions were more prevalent than negative interactions in the forest,which indicates that positive interactions may have important effects on forest species assemblies.