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Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this research on the spatial distribution pattern and correlation of populations is to predict the succession trend of populations and vegetation reconstruction which has a great significance meaning for further research investigation. Based on the geographic location and growth stage data of sand-fixing shrubs on fixed sand dunes in the Mu Us Sandy Land, the spatial distribution pattern and correlation of three dominant populations of Artemisia ordosica (AO), Hedysarum mongolicum (HM) and Caragana korshinskii (CK) were analyzed by using univariate and bivariate paired correlation functions and Monte Carlo fitting test. The results are as follows. (1) The three populations were aggregated at small scale and randomly or uniformly distributed at large scale; the populations of HM and CK showed aggregation distribution within the spatial scale of the study. (2) The interspecies relationships showed that AO and HM were negatively correlated at the scale less than 5 meters and basically uncorrelated at other scales. (3) The intraspecific correlation among different growth and development stages of the populations showed that the intraspecific relationships of the 3 populations were basically positively correlated at small scales. At large scales, there was a negative correlation between the intraspecifc relationships of AO, while there was no correlation between the intraspecifc relationships of HM and CK. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Xinjiang University (Natural Science Edition) is the property of Xinjiang University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The species of Sinojackia xylocarpa in sample plot of 1 hm² in Laoshan Mountain of Nanjing was taken as the object of study. Using the pairing correlation function g(r) and three null models: complete spatial randomness(CSR), heterogeneous Poisson(HP)and antecedent condition(AC)to analyze the relation between the structure and spatial distribution of the population. The potential mechanism of this pattern formation could be deeply recognized from the view of spatial pattern. The results were as follows:(1)The number of individuals of small DBH class in natural S. xylocarpa population was dominant, and it was a growing population.(2)In the study of point pattern analysis, the S. xylocarpa population showed the aggregate distribution at scale 0-26 m, and uniformly distribution at scale 29-30 m based on the CSR; and the S. xylocarpa population showed the aggregate distribution at scale 0-23 m, and uniformly distribution at scale 27-30 m based on the HP. The spatial distribution pattern of S. xylocarpa showed a trend of changing from aggregate distribution to uniformly distribution.(3) In the study of interspecific correlation, the spatial relationship between S. xylocarpa and Celtis sinensis showed from the negative correlation to the positive correlation. The spatial relationship between Sinojackia xylocarpa and Pistacia chinensis and that between Sinojackia xylocarpa and Acer buergerianum were about the same. There were positive correlations between them on a large scale, and occasionally negative correlation and no correlation. The above results indicate that Sinojackia xylocarpa population is in a good regeneration state. The spatial distribution pattern of S. xylocarpa population is basically aggregate distribution, and is mainly affected by interspecific competition, diffusion restriction and density restriction. Based on population status, carrying out in situ protection and appropriately disturbing the community are a scientific and effective protection measure for the endangered species of S. xylocarpa. [ABSTRACT FROM AUTHOR]

In order to study the formation and maintenance mechanism of forest landscape structure in Daxing’an Mountains, this paper studied the main forest landscape types（Larix gmelinii-Betula platyphylla mixed forest, Natural Larix gmelinii forest, Natural Betula platyphylla forest and Natural coniferous-broadleaved mixed forest） and their spatial distribution by using the first-order conditional intensity kernel density function and second-order conditional intensity O-ring statistic method based on Landsat TM remote sensing images in 2010 and a type of investigation data. The results showed that:（1） The main landscape types in Daxing’an Mountains were natural Larix gmelinii-Betula platyphylla mixed forest, natural Larix gmelinii forest, natural Betula platyphylla forest and natural coniferous-broadleaved mixed forest, accounting for 72.44% of the total area.（2） The results of kernel density analysis showed that spatial distribution of the four main landscape types had obvious aggressive characteristics. The mean patch density was 2.33-6.0 patch/km², and the coefficient of spatial variation was 39.7%-49.5%.（3） The four landscape types showed aggregative distribution on small scale（0-20 km）, and with the increase of scales, they showed random distribution or even distribution. （4） The landscape types showed significant positive or negative correlation on a small scale, but on a large scale they were mostly negative or no correlation. This study is the theoretical basis for sustainable forest management in this area. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the Quercus serrata var. brevipetiolata(Qs) forest in Baotianman Nature Reserve of Henan Province was considered as the study area. The dominant tree species in this forest were determined based on the importance values of the tree species. The spatial distribution patterns of the dominant tree species in the Qs forest were analyzed using Ripley′s K function in the point pattern analysis method, and the size distribution characteristics of the dominant population were identified through the analysis of their diameter class structure. The results were as follows. There were 11 tree species in the Qs forest in Baotianman Nature Reserve, and the dominant species were Qs, Platycarya strobilacea(Ps), and Dendrobenthamia japonica var. chinensis(Dj) whose importance values were 29.46, 15.41, and 11.98, respectively. Within 12 m of the central radius of the sample plot, the range of K(r) values of Qs and Ps were above the 99% confidence interval, which indicated Qs and Ps populations showed aggregated distributions, while that of K(r) values of Dj was within the 99% confidence interval, which indicated Dj population showed random distribution. The diameter class structure of all tree species in the arbor layer of Qs forest was the inverted J-shaped, which was the growth type. The diameter class structure of the Qs population was nearly normal distribution, which is the stable type. The diameter class structure of Ps was nearly J-shaped, which is the decline type, while that of Dj was nearly inverted J-shaped, which is the growth type. This study may serve as an important reference for future restoration and management measures for forests in Baotianman Nature Reserve. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As one of the protected areas, the wetland park has played an important role in protecting the wetland habitat. On one hand, the wetland park can be an important infrastructure for ecosystem research on exploring the contradiction between the vulnerability of ecologically fragile areas and the maintenance of original habitat of wetland, which shows both theoretic significance and practical value for systematic research on wetland parks. On the other hand, spatial analysis of the wetland park is an important basis for systematic construction of wetland parks. It can not only visualize the current spatial structure of wetland parks, but also reflect the wetland resources utilization and wetland management efficiency, which can provide the scientific basis for the spatial construction of wetland parks. Therefore, based on ArcGIS visualization technology, the spatial pattern characteristics of National Wetland Park (NWP) was analyzed from the perspective of time and space and its location relationships with the cities was explored by using Standard Deviation Ellipse, Point Pattern Analysis, Statistical Analysis and other methods. Results show the following four points: (1) China's NWP has gone through three stages, the starting stage, the rapid development stage and the standard development stage from time series. The amount of NWP is unevenly distributed in different provinces, and the correlation between the development of quality and quantity is not synchronized. Till now, Official National Wetland Park (ONWP) is at the beginning stage of standard development. (2) From multiple scale, an aggregated distribution pattern is emerging, supplemented by random distribution for ONWP. And the overall distribution pattern tends to be in a northeast- southwest direction, forming two high- density hot spots and three medium-density sub-hot spots. (3) From urban scale, the distribution of ONWP presents a large spatial heterogeneity and has the characteristics of being partial to the urban planning areas or being close to the urban planning areas. (4) At last, the distribution of ONWP presents the dominant characteristics of population pattern, which coincides with the guiding significance of Heihe-Tengchong Line. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central China Normal University is the property of Huazhong Normal University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, based on a 4 hm2 stem mapping plot, we analyzed spatial distributions of Abies georgei var. smithii, the dominant species in forest of Sygera Mountains in southeast Tibet, China. Pair-correlation function was used to characterize univariate spatial point patterns of three size classes of the population and bivariate spatial patterns between those and different sizes of dead wood. A. georgei var. smithii population was characterized by reverse J-shaped DBH distribution, indicating an increasing population. Saplings of the population were spatially obviously aggregated at the small scales (0-7 m), and mid-sized trees and large-sized trees of the population were randomly or uniformly distributed. The aggregation intensities of A. georgei var. smithii decreased with the increasing diameter classes and spatial scales. Saplings and mid-sized trees were significantly and negatively associated with large-sized trees at the small scales (0-35 and 0-30 m), but the associations reversed at the large scales (45-100 and 80-100 m). In addition, with the increasing age difference between diameter classes of the population, the intensities of positive or negative correlations increased. Spatial associations between saplings and dead large-sized trees, and between mid-sized trees and dead large-sized trees were negative at the small scales (0-34 and 5-27 m), but positive at the large scales (49-100 and 73-100 m). This suggested that released niche space due to dead large-sized trees is not enough to weaken their negative impacts on saplings. We concluded that self-thinning effect and Janzen-Connell hypothesis may be the main mechanisms for the spatial pattern formation of A. georgei var. smithii population. [ABSTRACT FROM AUTHOR]

Taking the Korean pine broadleaved forest in Liangshui Nature Reserve of Heilongjiang Province, Northeast China as test object, this paper studied the species composition and diameter class structure, and by using point pattern analysis, analyzed the spatial distribution pattern and spatial association of the main populations. In the Reserve, there were a total of 16 species with diameter greater than 1 cm in tree layer, and great differences were observed in the densities of main populations. Coniferous trees such as Pinus koraiensis and Abies nephrolepis were dominant. The diameter class structure of the populations presented as an inverse ''J'' curve, indicating a good re-generation across the community. The main populations were mostly in aggregated distribution pattern, except that the P. koraiensis populations at the scales of 19-21 m and 44 m as well as the Acer tegmentosum populations close to the largest research scale were in random distribution. The P. koraiensis populations at all research scales were approximately in random distribution, and had the minimum aggregation. A. nephrolepis, Tilia amurensis, and A. tegmentosum populations all presented a random distribution trend. Except that the P. koraiensis and A. nephrolepis at 2-3 m scale and the A. nephrolepis and A. tegmentosum populations at 37-81 m scale had significant positive association, no significant associations were observed between other populations. All the tree species presented an overall non-significant positive association. [ABSTRACT FROM AUTHOR]

An investigation was conducted on the species composition and population diameter-class structure of a typical secondary Betula albo-sinensis forest in Xiaolongshan of west Qinling Mountains, and the spatial distribution pattern and interspecific correlations of the main populations were analyzed at multiple scales by the O-ring functions of single variable and double variables. In the test forest, B. albo-sinensis was obviously dominant, but from the analysis of DBH class distribution, the B. albo-sinensis seedlings were short of, and the natural regeneration was very poor. On the contrary, the regeneration of Abies fargesii and Populus davidianas was fine. B. albo-sinensis and Salix matsudana had a random distribution at almost all scales, while A. fargesii and P. davidianas were significantly clumped at small scale. B. albo-sinensis had positive correlations with A. fargesii and P. davidianas at medium scale, whereas S. matsudana had negative correlations with B. albo-sinensis, A. fargesii, and P. davidianas at small scale. No significant correlations were observed between other species. The findings suggested that the spatial distribution patterns of the tree species depended on their biological characteristics at small scale, but on the environmental heterogeneity at larger scales. In a period of future time, B. albo-sinensis would still be dominant, but from a long-term view, it was necessary to take some artificial measures to improve the regeneration of B. albo-sinensis [ABSTRACT FROM AUTHOR]

By using Ripley's K function, an important method of point pattern analysis, and taking the TM remote sensing images of 1987, 1996 and 2007 as data source, this paper studied the characteristics and changes of landscape pattern in Wuhan City. The results showed that in 1987- 2007, farmland was the landscape matrix in Wuhan, while water body, forestland, grassland, urban and rural built-up land, and unutilized land types were the patches or corridors, which spatially clumped significantly in all scales. The landscape aggregation of water bodies was inferior to that of forestland, grassland, and urban and rural built-up land. The farmland clumped spatially in fine scales, but became random or uniform in coarse scales. Meantime, the areas of forestland and urban and rural built-up land increased largely, while water body, grassland, and farmland decreased greatly. In addition, the landscape spatial characteristics of all landscape types changed variously. On the whole, the landscape aggregation of forestland and urban and rural built-up land decreased, and became more uniform. Meanwhile, the water body, grassland, and farmland took on a more uneven and clumped landscape pattern. To analyze the landscape pattern through sample points had the advantages of conciseness, accuracy, and easiness-to-use, in comparison with the methods of quadrat and sample line (or transect). Ripley's K function was proved to be an efficient means for analyzing landscape pattern in different scales, and fit for the supplement and support of landscape metrics. [ABSTRACT FROM AUTHOR]

By using O-ring statistics in point pattern analysis and Programita software, this paper studied the spatial distribution patterns and associations of different age-class individuals of Taxus chinensis var. mairei populations at Xianyu and Xiaxiang in the mountainous area of southern Anhui Province. The Xianyu population had a random spatial distribution at the scales from 2 m to 25 m but a clumped distribution at the scales <2 m, while the Xiaxiang population distributed randomly at all the scales.As for Xianyu population, its individuals of age-class I had a clumped distribution at the scales <5 m,while the individuals of elder age-classes tended to be non-randomly distributed at more scales than <5 m, which might be related to the features of population regeneration.With increasingly enlarged age-class differences, the spatial association between younger and elder age-classes individuals turned to be negative, but less spatial association was observed between adjacent age-classes individuals. Such a spatial relationship between different age-classes individuals of T. chinensis was beneficial to the effective use of resources. With the growth of the individuals, T. chinensis population had a transition from clumped to random distribution. [ABSTRACT FROM AUTHOR]

Based on the investigation in a 4 hm2 Betula-Abies forest plot in sub-alpine area in West Sichuan of China, and by using point pattern analysis method in terms of O-ring statistics, the spatial patterns of dominant species Betula albo-sinensis and Abies faxoniana in different age classes in study area were analyzed, and the intra- and inter-species associations between these age classes were studied. B. albo-sinensis had a unimodal distribution of its DBH frequency, indicating a declining population, while A. faxoniana had a reverse J-shaped pattern, showing an increasing population. All the big trees of B. albo-sinensis and A. faxoniana were spatially in random at all scales, while the medium age and small trees were spatially clumped at small scales and tended to be randomly or evenly distributed with increasing spatial scale . The maximum aggregation degree decreased with increasing age class. Spatial as sociation mainly occurred at small scales. A. faxoniana generally showed positive intra-specific association, while B. albo-sinensis generally showed negative intra-specific association. For the two populations, big and small trees had no significant spatial association, but middle age trees had negative spatial association. Negative inter-specific associations of the two populations were commonly found in different age classes. The larger the difference of age class, the stronger the negative inter-specific association. [ABSTRACT FROM AUTHOR]

Helianthemum songaricum is a second-class protected plant in China, threatened by decreased population size and fragmentation of distribution area. It is a new record species in Ningxia. We analyzed population structure, spatial distribution, and relationship of different age classes of H. songaricum living in sandy and gravel habitats. The results showed that majority of H. songaricum individuals were belonged to age-class Ⅲ. The age structure of the population was inverted triangle. The population was at a declining stage. The spatial pattern and spatial association between different age class of H. songaricum were greatly affected by habitat condition, with strong dependence on spatial scale. Compared with sandy habitat, H. songaricum population in gravel habitat tended to be clustered distribution, with a more obvious positive correlation among different age classes. The difference between two habitats was related to environmental condition and plant community structure. H. songaricum from age-class Ⅰ and Ⅱ had mutually dependent ecological relationships.

Using the paired correlation equation g(r) in the spatial point patterns, we investigated the regeneration characteristics and spatial patterns of Castanopsis hystrix seedlings and the spatial correlation with the seed trees in the plantation by large diameter wood cultivation in south subtropical China. The results showed that natural seedling regeneration in C. hystrix plantation was good, which were widely distributed in the whole plantation. The seedling regeneration were mainly contributed by root sprouts, accounting for 73.6% of the total. The number distribution of C. hystrix seedlings in different age classes showed a pyramidal shape, with the contribution of diameter class1, 2 and 3 being 64.3%, 29.3% and 6.4% of the total, respectively. The C. hystrix seedlings mainly presented aggregated distribution in small scale (<15 m). With the increases of size classes and spatial scales, the aggregation strength gradually weakened and finally presented random distribution. The spatial correlation between seedlings and seed trees was not significant with the increases of size classes or spatial scale.

In Abies fargesii forests of the giant panda's habitats in Mt. Taibai, the spatial distribution patterns and interspecific associations of main tree species and their spatial associations with the understory flowering Fargesia qinlingensis were analyzed at multiple scales by univariate and bivaria-te O-ring function in point pattern analysis. The results showed that in the A. fargesii forest, the number of A. fargesii was largest but its population structure was in decline. The population of Betula platyphylla was relatively young, with a stable population structure, while the population of B. albo-sinensis declined. The three populations showed aggregated distributions at small scales and gradually showed random distributions with increasing spatial scales. Spatial associations among tree species were mainly showed at small scales and gradually became not spatially associated with increasing scale. A. fargesii and B. platyphylla were positively associated with flowering F. qinlingensis at large and medium scales, whereas B. albo-sinensis showed negatively associated with flowering F. qinlingensis at large and medium scales. The interaction between trees and F. qinlingensis in the habitats of giant panda promoted the dynamic succession and development of forests, which changed the environment of giant panda's habitats in Qinling.