Wang Xugao

Composition and interannual dynamics of tree seedlings in broad-leaved Korean pine (Pinus koraiensis) mixed forest in Changbai Mountain.

To explore the composition and interannual dynamics of tree seedlings in a broad-leaved Korean pine mixed forest, 600 25 m (5 m×5 m) seedling quadrats were set up in a 25-ha plot of the forest in Changbai Mountain. All seedlings in these quadrats were tagged, measured and identified to species. Based on three seedling censuses between 2006 and 2008, we analyzed species composition, spatial distribution, and interannual dynamics of tree seedlings. A total of 21 tree species were recorded in these quadrats, which was consistent with the composition of trees with ≥1 cm diameter at breast height. There was no significant interannual difference on species composition, but great variations among different seedling subplots. There were 11,959 tree seedlings recorded in three censuses, of which Fraxinus mandshurica and Tilia amurensis comprised of 72.75%. The seedling numbers of F. mandshurica, T. amurensis, and Pinus koraiensis varied greatly among three censuses, while the numbers of other species varied little. Recruit seedlings of 15 species were recorded in three censuses, of which 10 species (T. amurensis, F. mandshurica, P. koraiensis and so on) were found every year. The numbers of recruit seedlings showed great interannual variations 386 生 物 多 样 性 Biodiversity Science 第 17 卷 among different species and quadrats. Compared spatial distribution of tree seedlings with their seeds and large trees, we found that there were significant differences on individual numbers among different species. For T. amurensis, F. mandshurica, Acer mono, and A. pseudo-sieboldianum, their seeds and seedlings could be found in the entire 25-ha plot. For Ulmus japonica and Maackia amurensis, the distributions of their seedlings were inconsistent with their seeds and large trees. For T. mandshurica and Malus baccata, with fewer seeds, seedlings, and large trees, the distributions of seedlings were consistent with these of their seeds and large trees.

Composition and seasonal dynamics of seed rain in broad-leaved Korean pine (Pinus koraiensis) mixed forest in Changbai Mountain, China

Abstract To explore the composition and spatio-temporal dynamics of seed rain in broad-leaved Korean pine ( Pinus koraiensis ) mixed forest, 150 seed traps were set up in a 25 hm 2 plot in Changbai Mountain. Seeds, fruits, anthotaxy and others in seed traps were collected, identified and divided into 4 types. From 2005 to 2006, we collected 47 different types. Total number of seeds and fruits was 121291, including 23147 mature seeds and fruits (19.1% of the total). Tilia amurensis and Fraxinus mandshurica , with the most seeds and fruits, accounted for 90% of the total. The analysis on seasonal dynamics of seed rain showed that there were the largest number of seeds and fruits between July and October, which were composed of immature seeds and fruits. In mid-October, mature seeds and fruits reached their peak, but immature seeds and fruits still accounted for high proportion. There were 91 traps that contained 100–200 mature seeds and fruits, and one trap without any mature seed or fruit. The largest number of species found in a trap was 7, and usually 3 or 4 species were found in most of the traps. There were obvious relationships between spatial patterns of mature seeds and fruits and their parent trees, indicating that their mature seeds and fruits were not dispersed far from their parent trees.

Long-term effect of different planting proportions on forest landscape in Great Xing’an Mountains, Northeast China after the catastrophic fire in 1987

A landscape model (LANDIS) was used to study the long-term forest dynamics under five planting types (100% larch (P1); 70% larch and 30% Mongolian Scotch pine (Pinus sylvestris var. mongolica) (P2); 50% larch and 50% Mongolian Scotch pine (P3); 30% larch and 70% Mongolian Scotch pine (P4); 100% Mongolian Scotch pine (P5)), which were also employed in severely burned area under current planting intensity, and under natural regeneration (as a comparison) in Tuqiang Forest Bureau in the northern slopes of Great Xing’an Mountains after the catastrophic fire in 1987. Results showed that different planting types had a significant influence on the abundance of larch, Mongolian Scotch pine and white birch. The abundance of larch increased with time, whereas the abundance of Mongolian Scotch pine was in a converse way. The abundance of larch and Mongolian Scotch pine under these planting scenarios was higher than that under natural regeneration. Under these planting scenarios, the abundance of larch increased with the increasing proportion of larch, and the abundance of Mongolian Scotch pine was in a similar way. Contrary to larch and Mongolian Scotch pine, white birch had higher abundance under natural regeneration than that under these planting scenarios. Also, the different proportions of larch and Mongolian Scotch pine had an influence on the abundance of white birch. White birch had higher abundance with the increasing proportion of Mongolian Scotch pine. As for the total abundance of larch and Mongolian Scotch pine, the difference was not significant under P2, P3 and P4 scenarios, but was higher than that under P1 and P5 scenarios, which indicated that individual-species planting should not be used in the forest landscape.