Entity

Time filter

Source Type


Liu J.F.,Fujian Agriculture and forestry University | Liu J.F.,Key Laboratory of Fujian Universities for Ecology and Resource Statistics | Zhu D.H.,Fujian Agriculture and forestry University | Lan S.R.,Fujian Agriculture and forestry University | And 5 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2013

Daiyun Mountain is one of two great mountains in Fujian Provice, located at the boundary between mid-subtropic and south subtropic. Daiyun Mountain National Nature Reserve established in the sample area is one of the nature reserves with the highest biodiversity in unit area in China. Daiyun Mountain has 6400 hm2 protogenesis Pinus taiwanensis community which is the most south tip,the biggest area and the best preserved natural P. taiwanensis community area in China mainland. Daiyun Mountain also is the largest germplasm genetic base of P.taiwanensis in China, which is important to carry out research on the succession of mid-subtropical vegetation. Based on the field investigation of thirty-one sample plots (20 m × 20 m) of P.taiwanensis community in Daiyun Mountain, the environmental factors (11 soil factors and 4 terrain factors) were selected. The relevance between distribution pattern and environment was discussed by Detrended Canonical Correspondence Analysis (DCCA). The relationship among environmental factors was quantitatively analyzed. The results showed that:(1) The DCCA first sorting axis mainly reflected spatial variability of elevation, the second axis mainly reflected the change of slope, slope tends to the sunny side with the second axis from top to bottom, meanwhile P. taiwanensis communities distribute obviously. (2)The DCCA sorting indicated coefficient between the first axis and the elevation reaches 0.5570, that is, elevation is decisive function factor for P.taiwanensis communities,presenting the higher elevation is, the more remarkable P.taiwanensis population is especially in elevation 1400-1600 m.(3) Different species of P.taiwanensis communities has different environmental factors in the DCCA sorting chart, simultaneously the slope, the slope position, the organic matter, the human factor also are the important factors of P.taiwanensis communities. (4)The sorting results obtained from DCA (Detrended Correspondence Analysis), CCA(Canonical Correspondence Analysis)and DCCA have some differences.DCA mainly reflects P.taiwanensis community difference, while CCA exists "Arch Effect". With a combination of DCA and CCA, DCCA showed a higher correlation coefficient between the P.taiwanensis community and environmental sorting axis as compared with DCA, indicating that DCCA can give a better explanation on the relationship between P.taiwanensis community and environmental factors such as elevation and organic matter. Moreover, there is not "Arch Effect" in DCCA. Therefore, DCCA may be the best choice in study on the relationship between P. taiwanensis community and environmental factors. Source


Su S.,Fujian Agriculture and forestry University | Su S.,Key Laboratory of Fujian Universities for Ecology and Resource Statistics | Liu J.,Fujian Agriculture and forestry University | Liu J.,Key Laboratory of Fujian Universities for Ecology and Resource Statistics | And 5 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

The spatial heterogeneity of soil nutrients and soil pH in Castanopsis kawakamii natural forest of Sanming City, Fujian Province was studied by the method of Geostatistics coupled with Geographical Information System (GIS) technique. The experimental results showed that pH had a weak variation, and the soil nutrients exhibited medium spatial variability. The variation intensity of soil nutrients and soil pH ranked from high to low as follows: available phosphorous (43. 54%), available potassium (32. 84%), hydrolyzable nitrogen (31. 03%), total nitrogen (29. 41%), total potassium (25.25%), total phosphorous (22. 14%), pH (3. 39%). In terms of different soil layers, the value of pH and total potassium raised with increase in soil depth, while total nitrogen, total phosphorous, hydrolyzable nitrogen, available phosphorous, available potassium reduced with increasing soil depth. Analysis of variance showed that soil nutrients and soil pH reached an extremely significant levels. Parameters of theoretical variogram models for soil nutrients and soil pH showed that pH, total potassium and available phosphorous fitted exponential model, total nitrogen fitted Gaussian model, total phosphorous and hydrolyzable nitrogen can be best described by spherical model and available potassium was well fitted by linear model. The effective ranges of total potassium and available potassium were 1806 m and 549 m, respectively, while the values for pH, total nitrogen, total phosphorous, hydrolyzable nitrogen and available phosphorous were 267 m, 130 m, 120 m, 182 m, and 117 m, respectively. In terms of spatial structure, pH, total nitrogen, total phosphorous, hydrolyzable nitrogen and available phosphorous showed high spatial autocorrelation, which was greatly affected by soil structural factors, such as stand structure, topography, microhabitat of forest gap and soil aggregate structure. Total potassium indicated moderate spatial autocorrelation, which was resulted from both soil structural factors and random factors. Available potassium indicated weak spatial autocorrelation. The spatial heterogeneity of available potassium was primarily affected by random factors, such as site preparation, change of land use, the rapid development of the ecotourism, the planning and construction of scenic areas. The spatial distributions of soil nutrients had different characteristics. Total nitrogen and total phosphorous were increased from south to north. The total potassium emerged circle distribution with low in the central area and high in the marginal area. Soil pH showed a decreasing trend from southwest to northeast, presenting a band distribution. Hydrolyzable nitrogen decreased from northeast to southwest. Available phosphorous increased gradually from southeast to northwest. From southwest to northeast, available potassium content increased firstly and then decreased with two high value areas at the corner of northwest and southeast. The results may provide reference for improving the sampling design and for spatial interpolation and map of soil nutrients at a regional scale. It also may give a scientific foundation for sustainable use of soil and the recovery and reconstruction of C. kawakamii natural forest. Source


He Z.,Fujian Agriculture and forestry University | He Z.,Key Laboratory of Fujian Universities for Ecology and Resource Statistics | Liu J.,Fujian Agriculture and forestry University | Liu J.,Key Laboratory of Fujian Universities for Ecology and Resource Statistics | And 9 more authors.
Chinese Journal of Applied and Environmental Biology | Year: 2012

The competition among the Castanopsis kawakamii seedlings were calculated with improved competition model for individual tree of Hegyi, which were optimized by the exponential smoothing model. The optimum competition ranges were confirmed by single slope change point analysis. The results showed that: (1) The average competition intensity of the C. kawakamii seedlings decreased with increasing of the competition distance. The competition intensity decreased quickly at early stage and then slow down in a certain extent, and there existed a turning point in the change range called the seedlings competition zone in the C. kawakamii natural forest gap and understory. (2) The minimum mean square errors of the third index smooth values of the C. kawakamii seedlings competition intensity in the forest gap and understory were 0.401 5 and 0.385 1 when smoothing coefficient α=0.8 and α=0.7 respectively. By applying the method of single slope change point, the optimal sampling competition zone of the C. kawakamii seedlings competition intensity were 1.70 and 1.90 meters distance from the objective trees in forest gap and understory. The results help us to determine the competition zone for the C. kawakamii seedlings' competition pattern. Tab 3, Ref 20. Source


He Z.,Fujian Agriculture and forestry University | He Z.,Key Laboratory of Fujian Universities for Ecology and Resource Statistics | Liu J.,Fujian Agriculture and forestry University | Liu J.,Key Laboratory of Fujian Universities for Ecology and Resource Statistics | And 8 more authors.
Journal of Mountain Science | Year: 2012

The objective of this study was to understand the effects of forest gap and variations in different seasons, gap size, locations and diurnal variations on forest microclimate and soil water content. Spatial and temporal distribution features of air temperature (T A), soil temperature (T S), relative humidity (h) and soil water content (Ψ) were measured in Castanopsis kawakamii natural forest gaps created by a severe typhoon or fallen dead trees. The results showed that: (1) the variations of T A, h, and T S in four seasons were extremely significant. The variations of Ψ in four seasons were extremely significant except for those between spring and summer. (2) The diurnal variations of T A and T S were expressed with a single peak curve. The diurnal variations of h and Ψ presented a high-low-high trend. (3) The variations of T A, h, and T S were extremely significant among the large, medium and small gaps in C. kawakamii natural forest. Medium gaps had the highest T A and the lowest h while small gaps were just contrary to medium gaps. The variations of Ψ were extremely significant for large, medium and small gaps except those between the medium and large gaps. (4) The T A, h, T S and Ψ were decreased from the gap center, canopy gap, expanded gap to understory. These results will help further our understanding of the abiotic and consequent biotic responses to gaps in the mid-subtropical broadleaved forests, which also provide a theoretical basis for the scientific management and population restoration of C. kawakamii natural forest. © 2012 Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg. Source

Discover hidden collaborations