Effects of plant roots on soil preferential pathways and soil matrix in forest ecosystemsJournal of Northeast Forestry University - Tập 26 - Trang 397-404 - 2015
Yinghu Zhang, Jianzhi Niu, Weili Zhu, Xiaoqing Du, Jiao Li
To characterize effects of plant roots on preferential flow (PF), we measured root length density (RLD) and root biomass (RB) in Jiufeng National Forest Park, Beijing, China. Comparisons were made for RLD and RB between soil preferential pathways and soil matrices. RLD and RB declined with the increasing soil depth (0–10, 10–20, 20–30, 30–40, 40–50, 50–60 cm) in all experimental plots. RLD was gre...... hiện toàn bộ
Effect of sensor quantity on measurement accuracy of log inner defects by using stress waveJournal of Northeast Forestry University - Tập 18 - Trang 221-225 - 2007
Li-hai Wang, Hua-dong Xu, Ci-lin Zhou, Li Li, Xue-chun Yang
Wood nondestructive testing (NDT) is one of the high efficient methods in utilizing wood. This paper explained the principle of log defect testing by using stress wave, and analyzed the effects of sensor quantity on defect testing results by using stress wave in terms of image fitting degree and error rate. The results showed that for logs with diameter ranging from 20 to 40 cm, at least 12 sensor...... hiện toàn bộ
Self-thinning lines and allometric relation in Chinese fir (Cunninghamia lanceolata) standsJournal of Northeast Forestry University - Tập 26 - Trang 281-290 - 2015
Li Xue, Xiaoli Hou, Qiujing Li, Yunting Hao
We calculated a self-thinning exponent of 1.05 for tree mass using the 3/2 power equation in 93 Cunninghamia lanceolata plots. According to Weller’s allometric model, the self-thinning exponent for tree mass was calculated as 1.28 from the allometric exponents θ and δ. The both self-thinning exponents were significantly lower than 3/2. The self-thinning exponent of organs was estimated to be 1.42 ...... hiện toàn bộ
Dependences of longleaf pine (Pinus palustris) natural reproduction on environments above groundJournal of Northeast Forestry University - Tập 25 - Trang 565-570 - 2014
Qiuju Guo, Dexiang Wang, Xunru Ai, Lan Yao
We studied relations between natural seedling reproduction and above ground environment in a longleaf pine ecosystem. Forty-eight 0.05 ha circular plots were sampled under single-tree selection, grouptree selection and control stands in three main longleaf pine areas in south Alabama, USA. We measured six above-ground environment factors, viz. canopy closure, stand density, basal area, average tre...... hiện toàn bộ
Branching and growth of plantings in fifth year of a seedling seed orchard of Masson pine (Pinus massoniana Lamb.)Journal of Northeast Forestry University - Tập 13 - Trang 28-32 - 2002
Lai Huan-lin, Wang Zhang-rong, Jiang Rui-rong
The features of branching and growth studied included height, diameter at breast height (DBH), total number of branches, annual height growth, annual branch elongation in the year of elongating, annual branch number for four consecutive years, diameter of branches of different ages, and diameter of stem where branch-whorl originates. For features of total growth and overall branching, no significa...... hiện toàn bộ
Regeneration of pitch pine (Pinus rigida) stands inhibited by fire suppression in Albany Pine Bush Preserve, New YorkJournal of Northeast Forestry University - Tập 30 - Trang 233-242 - 2018
Chang-Seok Lee, George R. Robinson, Ingrid P. Robinson, Hansol Lee
The Pine Barrens in New York State are dominated by pitch pine (Pinus ridgida) and scrub oaks (Quercus ilicifolia and Q. prinoides). With fire suppression over the last 90 years or so, P. rigida regeneration has become sparse, even in areas set aside to preserve this type of vegetation. We evaluated the effects of fire and an alternative disturbance (mechanical removal of vegetation) for increasin...... hiện toàn bộ