Search

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.)

The study was conducted to examine the characteristics of natural regeneration and the spatial relation of seedlings and saplings in the mixed stand of Picea spp. + Larix principis-rupprechtii in Guandi Mountain. The spatial distribution pattern and heterogeneity of naturally occurring seedlings and saplings were studied using the method of adjacent lattice combined with the semivariance function. The results showed that the regeneration density of the understory community was 450-1 350 trees • hm-2, which was dominated by Picea spp., accounting for 81.74% of the community. The regeneration density of Picea spp. was 688 trees • hm-2, and that of L. prirzcipis-rupprechtii was 167 trees•hm-2, the latter demonstrating poor regeneration. A majority of the seedlings and saplings were clustered, and the clustering intensity gradually decreasing with increasing scale. A strong spatial autocorrelation was observed between the seedlings and saplings. Structural and random factors were responsible for 79.6% and 20.4% of variations in the distribution pattern, respectively. The spatial distribution of seedlings and saplings demonstrated anisotropy, with a dominant northeast to southwest pattern and subdominant northwest to southeast pattern. The spatial autocorrelation range of the ground diameter and tree height of seedlings and saplings were 11.25 and 13.85 m, respectively. Structural factors had a greater influence on the spatial heterogeneity, which was stronger in the horizontal direction. [ABSTRACT FROM AUTHOR]

In order to evaluate the carbon storage capacity of pure stands and mixed stands of Fraxinus mandschurica and Larix olgensis plantation, 24-year-old stands were selected in Maoershan area, Shangzhi City, Heilongjiang Province, to measure carbon storage. Results showed that the ecosystem carbon storage of the mixed stand (246.15 t C·hm-2) was greater than those of the L. olgensis (232.01 t C·hm-2) and F. mandshurica (211.86 t C·hm-2) pure stands, but there were no significant differences (P > 0.05). In the three stands, carbon storage of soil layer and tree layer, which were the majority carbon storage in the ecosystems, were accounted for 71.6% ~ 80.1% and 17.3% ~ 24.5% respectively. The carbon storage of soil in the mixed stand was greater than those in two pure stands, but the differences were not significant (P > 0.05). The carbon storage of tree layer in the mixed stand was greater than those in the two pure stands, with a significant difference between the mixed stand and the F. mandshurica pure stand (P < 0.05). The carbon storage of the litter layer in F. manshurica was significantly less than the others (P < 0.05), while the storage of the understory vegetation was significantly greater (P < 0.05). Results show that the mixed stand of F. mandshurica and L. olgensis can increase the carbon fixation of ecosystem compared with the pure stands, which is suitable for building carbon sink forest. [ABSTRACT FROM AUTHOR]