Pinus Tabulaeformis Forest Research Articles

Effect of forest vegetation on runoff and sediment production in sloping lands of Loess area

According to fixed-position data for 1985–2003 from nine runoff plots of Caijiachuan watershed which lies in Jixian County of Shanxi Province in Loess area, this paper studied the relationship between vegetation and runoff and sediment production in sloping lands in detail, which helps to provide scientific basis for vegetation re-construction and studies on environmental transformation of water and sediment in watersheds of Loess area. Although, many study results testify that forest vegetation has an important function in soil and water conservation and cutting runoff, the effect of vegetation on runoff and sediment transmission is complicated, and this needs to be studied in depth. The results of the paper showed the following. Firstly, the natural secondary forest performs better function of soil and water conservation than artificial Robinia pseudoacacia forest, and runoff and sediment produced in the former in individual rainfall were 65%–82% and 23%–92% of those produced in the latter. At the same time, better correlative relationship between runoff and sediment production and rainfall and rainfall intensity were testified by multiple regression, but the correlation decreased gradually with the increase of canopy density of forest. Secondly, the difference of runoff and sediment production in several land use types was very distinct, and the amount of runoff and sediment produced from Ostryopsis davidiana forest and natural secondary forest were the least, and runoff and sediment produced from in artificial Robinia pseudoacacia forest and Pinus tabulaeformis forest were 5-fold as much as those from O. davidiana forest. Besides, runoff and sediment produced in mixed planting of apple trees and crops were 16.14-fold and 2.96-fold than those of O. davidiana forest, respectively, but the amount decreased obviously after high-standard soil preparation in the case of the former. Thirdly, based on gray cognate analyses of factors affecting runoff and sediment production in sloping land, the factors of stand canopy density and herb and litter biomass were the most significant ones, whose gray incidence degree exceeded 0.6. Therefore, mixed forest with multi-layer stand structure and shrub forest should be developed in vegetation re-construction of Loess area, which will help to increase coverage and litter thickness in order to cut down the runoff and sediment dramatically in sloping land.

Comparative Analysis of Plant Diversity of Pinus tabulaeformis Forests in Ten Regions of Beijing Mountainous Areas

Based on investigations during 1998–2003, shrubs and herbs, as well as indicators of similarity and diversity in Pinus tabulaeformis forests of ten regions around Beijing were compared and analyzed, and protection measures were suggested. Generally, the shrubs and herbs in P. tabulaeformis forests of Shidu, Mutianyu, and Yunfengshan are rich in species diversity and have great similarities. The percentages of common species in each of these three paired regions are above 50%, while many peculiar plant species that could not be found in the other nine regions exist in Labagoumen. As for plant diversity indices, plants in the P. tabulaeformis forests of Baihuashan, Shidu, and Labagoumen occur more frequently than in other regions, while the number of plants in Tanjiesi and Miaofengshan are far less. Some endangered orchid species were found distributed in P. tabulaeformis forests with a clumped spatial pattern but rarely appeared in other forest types, indicating that P. tabulaeformis forests are ideal habitats for orchid species.

A new methodology for estimating forest NPP based on forest inventory data—A case study of Chinese pine forest

Accurately estimating forest net primary productivity (NPP) plays an important role in study of global carbon budget. A NPP model reflecting the synthetic effects of both biotic (forest stand age, A and stem volume, V) and climatic factors (mean annual actual evapotranspiration, E) was developed for Chinese pine (Pinus tabulaeformis) forest by making full use of Forest Inventory Data (FID) and dynamically assessing forest productivity. The NPP of Chinese pine forest was estimated by using this model and the fourth FID (1989–1993), and the spatial pattern of NPP of Chinese pine forest was given by Geography Information System (GIS) software. The results indicated that mean NPP value, of Chinese pine forest was 7.82 t m−2·a−1 and varied at the range of 3.32–11.87 t hm−2·a−1. NPP distribution of Chinese pine forests was significantly different in different regions, higher in the south and lower in the north of China. In terms of the main distribution regions of Chinese pine, the NPPs of Chinese pine forest in Shanxi and Shaanxi provinces were in middle level, with an average NPP of 7.4 t hm−2·a−1, that in the southern and the eastern parts (e.g. Shichuang Hunan, Henan, and Liaoning provinces) was higher (over 7.7 t hm−2·a−1), and that in the northern part and western part (e.g. Neimenggu and Ningxia provinces) was lower (below 5 t hm−2·a−1). This study provides an efficient way for using FID to understand the dynamics of foest NPP and evaluate its effects on global climate change.

GROUND BRYOPHYTE COMPOSITION AND SYNUSIA STRUCTURE UNDER SIX TYPES OF YOUNG CONIFEROUS FOREST PLANTATIONS IN THE UPPER MINJIANG RIVER

Bryophytes on the ground under six types of artificial forests, Picea balfouriana forest (P), Pinus tabulaeformis forest (Y), Pinus armandii forest (H), Larix kaempferi forest (L), Picea balfouriana-Pinus tabulaeformis forest (P-Y) and Pinus tabulaeformis-Pinus armandii forest (Y-H), were investigated in the upper Minjiang River in order to understand the bryophyte composition and synusia structure of these different forest types. In the 19 bryophyte species identified, only 13, 10, 7, 11, 9 and 10 species were present in the P, L, H, Y-H, Y and P-H forests, respectively. Four mosses, Brachythecium glaciale, Thuidium cymbifolium, Entodon concinnus and Eurhynchium savatieri, were common in all six plantations. Another three mosses, Entodon macropodus, Mnium spinosum and Polytrichum formosum, occurred only in the Picea balfouriana forest. The highest frequency of bryophyte occurrence was under the P forest (90%) and the lowest frequency under the H forest ( 17.65% ). Thuidium cymbifolium had the highest frequency (60%) of all species under the P forest, and the second was Brachythecium glaciale (50%). The predominant species, based on the importance value, was Thuidium cymbifolium under the P forest and Brachythecium glaciale, occurred under the other five plantations, which indicated that Brachythecium glaciale was the most common moss species in the study area. In all forests, the P forest had the highest bryophyte diversity (Shannon-Wiener index, species richness index) and the H forest had the lowest diversity. The lowest Simpson index was calculated for the H forest and the highest one for the P forest. The highest similarity index (Sorensen similarity) occurred between the H and Y forests (0.89) and the lowest similarity index between the P and H forests (0.40). The greatest percent coverage (17.79%±1.67%), shoot density ((3 807.11±412.90) shoots·m -2 ) and thickness ((19.89±1.69) mm) of bryophytes occurred under the P forest, and the lowest values (0.41% ±1.49%, (27.99±367.95) shoots·m -2 , and (1.80±1.51) mm, respectively) under the H forest. For the Y, L, Y-H and P-H forests, ground bryophyte cover was 5.20%±1.58%, 2.44%±1.58%. 2.73%±1.61%, and 2.71%±1.61%, respectively, shoot density was (623.08±391.71), (566.13±391.71), (253.38±398.41), and (188.69±398.41) shoots·m -2 , respectively, and average bryophyte thickness was (9.60±1.61), (14.93±1.61), (9.59±1.63), and (6.69±1.63) mm, respectively. No statistical differences (p0.05) were found in any of these measures among the Y, L, Y-H and P-H forests. The low bryophyte diversity and limited structure development (density, coverage, thickness) found under all six plantations indicate that, in general, these are poorly developed bryophyte communities. Our results show that the best bryophyte community have developed under the spruce forest with a relatively open canopy and low tree density. Our results suggest that tree thinning or canopy pruning would be an effective measure for improving bryophyte development under dense forests.

Forest landscape pattern dynamics of Luoning County in Henan Province and its driving forces

With the help of ARC/INFOR and ERDAS software, based on the information from forest resources distribution maps and TM images, four indices were chosen to analyze spatial pattern changes of forest landscape of Luoning County, Henan Province from 1983 to 1999. The results showed that: 1) The number and total area of patches were rapidly increased with time changes. The fragmentation degree of the landscape was increasing greatly. 2) The area of some forest patch types, especially shrub forest, economic forest, Populus spp. forest, Quercus spp. forest, sparse forest, deserted grassland etc. had been greatly changed. 3) The fragemation degree of each forest patch type became greater from 1983 to 1999. 4) The transition probabilities of deserted forest, economic forest, Pinus tabulaeformis forest, Populus spp. forest exceed 85%, Robinia pseuoacacia forest, deserted grassland, 65% and Quercus spp. forest, non-forest, shrub forest had smaller ones, which were 26.5%, 29.1% and 45.3%, respectively. The main transition trends of various patches were non-forest and Quercus spp. forest. During the course of transition, the types that 50% of area was remained were Quercus spp. forest, non-forest and shrub forest. According to above analyses, the main driving forces, such as the management policies, market economy factors and influences of human activities etc. were brought out.

Variation in needle longevity of Pinus tabulaeformis forests at different geographic scales.

Needle longevity of conifer species is known to increase with latitude, but little is known about intraspecific variation and associated factors within a location. Chinese pine (Pinus tabulaeformis Carr.) forests were investigated to identify patterns of needle longevity at seven sites with distinctive climatic conditions along a latitudinal gradient (33-38 degrees N) in Shaanxi province, northwest China. A demographic approach was used to quantify needle longevity as an index of entire foliage population adjusted to needle-age-specific mortality rates. There were significant differences in needle longevity of Chinese pine stands across sites and across sample plots within a site. Individual tree needle longevity ranged from 0.62 to 3.75 years for 276 samples across sites. Needle longevity increased with latitude (R2 = 0.40, P < 0.0001), but decreased with mean January temperature (R2 = 0.63, P < 0.0001). Foliage retention of Chinese pine stands at the regional level was generally associated with climatic variability, indicating that variation in needle longevity was primarily an environmental acclimation to low temperature in winter. Stand characteristics were closely associated with needle longevity at three sites located within the same climatic zone. Needle longevity was positively correlated with tree age (R2 = 0.48, P < 0.0001) and stand density (R2 = 0.26, P = 0.0015) at Huanglong and Huangling, respectively, whereas it was negatively associated with total tree height at Zhidan (R2 = 0.50, P < 0.0001). It is concluded that, at the stand and individual tree level, intraspecific variation in needle longevity is most likely a result of adaptation to patchy microsite environments.

Stand Structure and Regeneration of Pinus tabulaeformis Forest in the Taiyue Forest Region, Shanxi Province, China

中華人民共和国山西省沁源県に位置する麻池背地区 (N36゜39'8'', E112゜04'18'', alt. 1, 670m) でPinus tabulaeformisの天然生林に50m×50mのプロットを2つ設置し, 林分構造と更新に関する調査を行った。調査地付近の年平均気温は7.8℃, 年降水量は581.4mmであり, 調査林分は山西省では最も蓄積が大きいと考えられているP. tabulaeformis林である。2つの調査プロットにおける胸高断面積合計は48.6m2/haおよび50.1m2/haであり, 胸高直径3cm以上の樹木の平均樹高はそれぞれ17.5mと13.9mであった。調査プロットの胸高直径3cm以上の樹木では10-14種出現したが, 最も優占していたのはP. tabulaeformisであり, 胸高断面積合計の99%を占めた。P.tabulaeformis上層木の齢分布は両プロットとも60-70年のクラスに集中し, 調査地の上層木は約70年前に一斉に更新したものであると考えられた。高木の後継樹としてはP.tabulaeformisとQuercusliaotungensisが多くみられた。P. tabulaeformisの稚樹はギャップに多く出現し, Q.liaotungensisはギャップと林冠下の両方に出現した。このようなP.tabulaeformisとQ.liaotungensisの更新様式の違いが今後の林分動態に影響を与えるものと考えられた。