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Lin L.,Tibet University | Luo J.,Research Institute of Tibet Plateau Ecology
Forest Research | Year: 2014

In order to understand the variation in main growth traits of Picea likiangensis var. linzhiensis at seedling stage, eight seedling traits from 9 provenances in its natural distribution ranges were examined using field seed origin experiment. The results indicated: (1) Except for the lateral root number, the other seven seedling growth traits among 9 provenances showed significant differences; (2) The correlation analysis showed that the seedling height, basal diameter and aboveground biomass were significantly positive-correlated with the longitude, and significant negative-correlated with the altitude, but not significant correlated with the latitude. Interestingly, the taproot length and root/shoot ratio were significant negative-correlated with the longitude. These results suggested that there was a significant provenance geographical variation trend in Picea likiangensis var. linzhiensis at seedling stage; (3) By cluster analysis, the 9 provenances tested could be divided into two geographical provenance groups, the eastern group and the western group. The western group had higher adaptation to drought and cooling, although the increment of eastern group was higher in seedling stage.


Lin L.,Tibet University | Ye Y.-H.,Tibet University | Luo J.,Research Institute of Tibet Plateau Ecology | Chen S.,Tibet University | Wang J.-H.,Chinese Academy of Forestry
Forest Research | Year: 2014

The characteristics of seed germination of six Sophora moorcroftiana provenances were examined, and the relationships among seed size, germination and elevation were analyzed. The results indicated that: 1) the number of seed per pod varied from 2.96 to 4.50, the mass of 1 000 seed ranged from 30.639 g to 47.415 g, the seed length and width varied from 4.314~4.926 mm and 3.244~3.693 mm, respectively, and the ratios of seed length to width ranged from 1.306 to 1.383. The analysis of variance showed that except the ratios of seed length to width, there were significant differences in the number of seed per pod, the mass of 1 000 seed, the seed length and width among provenances; 2) the percentage of seed germination changed from 43.16% to 90.03% among six provenances, of which the highest was Sajia provenance and the lowest was Mirui provenance; 3); the difference in the start time of seed germination among six provenances was only one day; the persistent time of seed germination varied from 14 to 23 days and the maximum difference in it among the six provenances was 9 days; the summit of seed germination ranged from 17 to 27 days, and it was a large difference among provenances, of which the longest was Sajia provenance and the shortest was Langxian provenance; 4) with increasing altitude, the number of seed per pod significantly declined (R=-0.844 3, P<0.05), while the mass of 1 000 seed apparently increased (R=0.614 3, P<0.05); 5) the start time of seed germination was negatively but not significantly related with the altitude; the persistent time of seed germination was significantly and negatively correlated with the altitude (R=-0.883 6, P<0.05), by contrast, the percentage of seed germination was significantly and positively related with the altitude (R=0.804 7, P<0.05).


Wang G.-Y.,Tibet Agriculture and Animal Husbandry College | Wang G.-Y.,Research Institute of Tibet Plateau Ecology | Luo J.,Research Institute of Tibet Plateau Ecology | Xu A.-S.,Research Institute of Tibet Plateau Ecology | Zhuang Y.-M.,Tibet Agriculture and Animal Husbandry College
Forest Research | Year: 2011

Quercus aquifolioides is a representative broadleaf evergreen species on the Qinghai-Tibet Plateau, which has a extensive, continuous distribution in the southeast Tibet forest region. It plays an important role on soil and water conservation of the alpine-gorge areas. The population structure, quantitative dynamics, the relationships between height and environment were studied using composition of size classes, life table, survival curve, and rank correlation analysis. The result indicated that: (1) the whole Quercus aquifolioides population took on a growing trend and the distribution of tree ages differed among plots (P<0.001), population regeneration better in gaps and was discontinuous in time domain. Slash-type population had approximately even-aged trees, showing the feature of disclimax, which would be possibly succeeded by another forest. (2) The survivorship curve was between Deevy type II and III. There were 4 mortality peaks in the tree's life, and the largest occurred while the seedlings growing into saplings (mortality reached 77.3%). The high mortality might result in high life expectation, the main reason of individual lifespan and population fluctuation is intraspecific resource competition. (3)The degree order of six factors influencing the population height was:Soil moisture>Annual rainfull>Position>Slope aspect>Slope>Altitude, the soil moisture and annual precipitation had significant impacts on the population's canopy height differentiation. In addition, the population had a wide adaptation on altitude and a weak response to the slope. The spatial water pattern significantly affected the individual growing and population development.


Xie C.-Q.,Research Institute of Tibet Plateau Ecology | Xie C.-Q.,Tibet Agricultural and Animal Husbandry College | Tian M.-X.,Research Institute of Tibet Plateau Ecology | Tian M.-X.,Tibet Agricultural and Animal Husbandry College | And 4 more authors.
Chinese Journal of Applied Ecology | Year: 2015

In this study, based on a 4 hm2stem-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 midsized 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. ©, 2015, Editorial Board of Chinese Journal of Applied Ecology. All right reserved.


Wang G.-Y.,Tibet Agricultural and Animal Husbandry College | Wang G.-Y.,Research Institute of Tibet Plateau Ecology | Luo J.,Research Institute of Tibet Plateau Ecology | Xu A.-S.,Research Institute of Tibet Plateau Ecology | Lu C.,Tibet Agricultural and Animal Husbandry College
Forest Research | Year: 2012

The special topographic and climate conditions of Himalaya-Hengduan Mountains gestate a rich forest resource, and plant and animal diversity in southeast Tibet. Through plot investigation, the species diversity and spatial distribution of Quercus aquifolioides community in southeast Tibet were studied using diversity index and detrended canonical correspondence analysis (DCCA) combining with specific association, interspecific covariation and systematic cluster analysis. The results indicated that: (1) The species richness decreased with the raise of altitude, but a certain degree of human disturbance (i. e. moderate disturbance), higher canopy density and lower canopy layer usually increased the species diversity. In addition, the pattern of species diversity was influenced by the microclimate of dry valley. (2) The species diversities of different layers in the community appeared as herb layer > shrub layer > tree layer. (3) Theoretically, the higher ratios of positive and negative association implied the more stable community structure, and the ecological habits and distributional differences among species of Q. aquifolioides community formed different interspecific relationship. Moreover, the distribution of species was mainly affected by altitudinal gradient and annual precipitation. (4) According to the outcomes of DCCA, specific association, interspecific covariation and systematic cluster analysis, the main populations of Q. aquifolioides community could be divided into four ecological species groups, it helps to understanding the local community structure and plant ecological habits, and further studying on the community succession, conservation and utilization.


Wang G.,Tibet Agriculture and Animal Husbandry College | Wang G.,Research Institute of Tibet Plateau Ecology | Luo J.,Research Institute of Tibet Plateau Ecology | Xu A.,Research Institute of Tibet Plateau Ecology
Chinese Journal of Applied and Environmental Biology | Year: 2010

Quercus aquifolioides is a representative broad-leaved evergreen species on the Qinghai-Tibet Plateau, and it extensively and continuously distributes in the forest region of southeast Tibet, China. This species plays an important role in soil and water conservation of the alpine-gorge areas. Its population spatial distribution pattern, population growth and regulation were studied using aggregate indices, logistic equation and power equation. The results indicated that the distribution patterns of its seedlings were clumped, and the aggregating power was minished during the progress of succession; the environmental capacity of its population was 15.208 5 m2 hm 2; the intrinsic rate of increase was 0.614; the highest growth rate appeared when the breast-height basal area was 9.66 m2 hm 2; and the maximum self-thinning intensity appeared when the average breast-height basal area ranged between 46.23 cm2 and 198.723 cm 2. Aggregation of Q. aquifolioides population was minished with development of its succession. This was an obvious phenomenon of population self-thinning and self-regulation in the environment with limited carrying capacity. Logistic equation reflected that the decline of population growth rate and the time delay effect were caused by the limitation of environmental carrying capacity. And the power function indicated that after mass regeneration, the competition for resources increased because of its individual growth, and as a result, the self-regulating process of selecting the superiors and eliminating the inferiors occurred within the population of Q. aquifolioides.

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