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1.
Mingdong Ma Chengde Luo Hong Jiang Yuejian Liu Xi Li 《Frontiers of Forestry in China》2009,4(2):140-145
Biomass, carbon content, carbon storage and spatial distribution in the 32-year-old Phoebe bournei artificial forest were measured. The mean biomass of the forest stand was 174.33 t/hm2, among which the arbor layer was 166.73 t/hm2, which accounted for 95.6%. Carbon contents of stems, barks, branches, leaves, root, shrub layer, herb layer, lichen layer
and litter layer were 0.5769 g C/g, 0.4654 g C/g, 0.5232 g C/g, 0.4958 g C/g, 0.4931 g C/g, 0.4989 g C/g, 0.4733 g C/g, 0.4143
g C/g, 0.3882 g C/g, respectively. The mean carbon content of soil was 0.0139 g C/g, which reduced gradually along with soil
depth. Total carbon storage of the P. bournei stand ecosystem was 227.59 t/hm2, among which the arbor layer accounted for 40.13% (91.33 t/hm2), the shrub layer accounted for 0.17% (0.38 t/hm2), the herb layer accounted for 0.76% (1.71 t/hm2), the lichen layer accounted for 0.28% (0.63 t/hm2), and the litter layer accounted for 0.29% (0.66 t/hm2). Carbon content (0–80 cm) of the forest soil was 58.40% (132.88 t/hm2). Spatial distribution ranking of carbon storage was: soil layer (0–80 cm) > arbor layer > herb layer > litter layer > lichen
layer > shrub layer. Net production of the forest stand was 8.5706 t/(hm2·a), in which the arbor layer was 6.6691 t/(hm2·a), and it accounted for 77.82%. Net annual carbon sequestration of the P. bournei stand was 4.2536 t/(hm2·a), and the arbor layer was 3.5736 t/(hm2·a), which accounted for 84.01%.
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Translated from Scientia Silvae Sinicae, 2008, 44(3): 34–39 [译自: 林业科学] 相似文献
2.
在2009年3—10月对浙江庙山坞自然保护区人工毛竹林的水文生态特征进行了定位样地和径流场观测研究,以探讨其林内降水分配规律和水土保持功能。结果表明:(1)观测期内,林外总降水量达1 220.8 mm,穿透雨量、茎流量、林冠截留量分别占总降水量的78.2%、7.3%和14.5%。随着林外降水量的增加,穿透雨量、茎流量呈线性增加,而林冠截留量先是迅速增加,当林外降水量达10 mm后增速减缓,并趋于稳定(5 - 6 mm)。(2)人工毛竹林林地凋落物现存量平均为4.37 t·hm-2,最 相似文献
3.
Chen Hongji 《林业研究》1999,10(3):181-182
Different types of plantations were observed in Baishilazi National Nature Reserve, Liaoning Province, for 34 a. The environmental
quality ofAbies holophylla plantations was analyzed under different cutting systems. Analysis factors included soil erosion rate, humification degree
of litters, and water hold capacity. The surface soil loss of clear cutting area was 19000t·km−2·a−1 more than that of selective cutting area. The content of soil organic matter in board-leaved—Abies holophylla forest was 4.62% more than that in pure stand, and the water hold capacity of the mixed forest was 1.43 time of that of pure
stand. The mixed forest of board-leaved—Abies holophylla by selective cutting can upgrade the ecological environment quality.
This paper is a part of a key project from Liaoning Science Committee.
Responsible editor: Zhu Hong 相似文献
4.
Based on data collected (through local observations) for several consecutive years, comparative analyses of Chinese fir plantations
in Huitong, Hunan, were made. Results show that, before harvesting, carbon storage in forest soils in these 22-year-old plantations
(0–60 cm) amounted to 160.38 t/hm2; 1 year after a 100% clear-cutting, loss of carbon storage in the soil (0–60 cm) of cutover areas was 35.00%; 2 years later,
the rate was 44.65%; and, after 3 years, the rate was 43.93% compared with a control area of a standing forest. Three years
after 50% thinning and 100% clear-cutting, the loss of carbon storage in the soil (0–60 cm) of cutover areas was 16.14 and
45.15%, respectively. There existed an evident difference in carbon storage in the soil (0–60 cm) of cutover areas in four
kinds of management regimes, which followed the order: closed Chinese fir forests (108.20 t/hm2) > fallow lands after farming (92.68 t/hm2) > commercial forests (85.80 t/hm2) > naturally regenerated forestlands after harvesting. Carbon storage in unburnt soil (0–45 cm) reached 73.36 t/hm2, which was 15.20 t/hm2 higher than that in the soil of burnt areas. A total of 20.7% of carbon storage in the soil (0–45 cm) of burnt areas was
lost 40 days after burning. Carbon storage in surface soil (0–15 cm) was higher than in the lower soil layer, which amounted
to 30.04% (0–60 cm) and 53.52% (0–30 cm) of total carbon storage in the soil.
Translated from the Journal of Central South
Forestry University, 2004, 24(1) (in Chinese) 相似文献
5.
To study the growth and yield of Acacia mangium in the Caribbean region of Colombia, allometric equations of total volume and aboveground plus coarse roots biomass were
fitted as a function of the tree’s diameter at breast height (dbh). The von Bertalanffy’s growth model and 59, 0.1 ha plots
(0.55–9.55 years old) were used to develop site index (SI) curves at 6 years base age. Then, using the state-space approach,
stand growth and yield models were developed for basal area, volume and biomass. The results show that A. mangium is a very promising species for timber production, atmospheric carbon removal and soil restoration because it grows very
fast even in mining degraded soils. On average sites it reaches 15 m in height in 3 years. However, early and reiterated thinning
coupled with initial mortality by cattle invasion of the very young understocked plantations are producing relatively low
yields. 相似文献
6.
We assessed the vertical distribution of litter and its seasonal patterns in the canopy and on the forest floor (soil), as
well as litterfall (the flux of litter from the canopy to the soil) in a 33-year-old plantation of Japanese cedar (Cryptomeria japonica D. Don). The masses of total litter, dead leaves, and dead branches in the canopy of C. japonica trees averaged 34.09, 19.53, and 14.56 t dry wt ha−1, respectively, and were almost constant during the study period. The total masses of the annual litterfall were 4.17 and
5.88 t dry wt ha−1 year−1 in the two consecutive years of the study. The mass of the soil litter averaged 7.95 t dry wt ha−1 during the same period. All relationships between the mass of canopy litter and tree-size parameters (diameters at breast
height and at the lowest living branch) were linear in a log-linear regression. Compared with the results for this plantation
at a younger stage (16 years old), our results suggest that the total mass of dead leaves attached to each tree increases
markedly with increasing age, but that the trajectory of this increase as a function of tree size may change from an exponential
to a saturation curve with increasing stand age. 相似文献
7.
Choonsig Kim 《Journal of Forest Research》1998,3(2):85-89
The objective of this study was to determine the rate of nitrogen (N) mineralization in response to various levels of canopy
cover in red pine (Pinus resinosa Ait.) stands. Experimental plots consisted of various levels of canopy cover,i.e., clearcut, 25% (50% during first sampling year), 75%, and uncut in red pine plantations in northern Lower Michigan, USA.
Net N mineralization and nitrification in the top 15 cm of mineral soil were examined during the first two growing seasons
(1991–1992) following the canopy cover manipulations, using anin situ buried bag technique. Mean net N mineralization over the course of both growing seasons (May–October) ranged from 26.9 kg
ha−1 per growing season in the clearcut treatment to 13.4 kg ha−1 per growing season in the uncut stand. Net N mineralization and nitrification increased significantly in the clearcut treatment
compared to the uncut treatment during the second growing season only. However, net N mineralization and nitrification did
not differ significantly between the partial canopy cover treatments and the uncut stand. Increased N mineralization and nitrification
in the clearcut during the second growing season may be associated with increased soil temperature and changes of organic
matter quality with time since canopy removal.
This study was supported in part by the USDA Forest Service and Michigan Technological University. 相似文献
8.
采用时空互换法,于广西南丹县山口林场选取不同林龄(9、14、20 a)的秃杉人工林作为研究对象,对其土壤物理性质、化学性质和生物化学性质(土壤酶活性)进行研究。结果表明:不同林分年龄土壤性质存在一定的差异,8、14、20 a秃杉人工林表层土壤(0 20 cm)土壤密度分别为0.978、0.914、0.890 g·cm-3,总孔隙度分别为63.10%、65.53 %、66.40%,土壤最大持水量分别为64.55%、71.70%、74.58%。随着林龄的增长,土壤各化学和生物化学指标的变化不尽相同,但林分年龄到20年生时,多数土壤养分和酶活性指标都有所升高,土壤肥力状况得到提高。 相似文献
9.
The role of canopy interception on nutrient cycling in Chinese fir plantation ecosystem was studied on the basis of the position
data during four years. Results indicate that the average canopy interception amount was 267.0 mm/year. Canopy interception
play a significant role in water cycle and nutrient cycle processes in ecosystem, and was an important part of evaporation
from the Chinese fir plantation ecosystem, being up to 27.2%. The evaporation from the canopy interception was an important
way of water output from ecosystem, up to 19.9%. The flush-eluviation of branches and leaves caused by canopy interception
brought nutrient input of 143.629 kg/(hm2 · year), which was 117.2% of the input 63.924 kg/(hm2 · year) from the atmospheric precipitation. The decreased amount of 80.1 mm precipitation input caused by canopy interception
reduced the amount of rainfall into the stand surface and infiltration into the soil, reduced the output with runoff and drainage,
and decreased nutrient loss through output water. Therefore, the additional preserve of nutrient by canopy interception was
8.664 kg/(hm2 · year).
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Translated from Scientia Silvae Sinicae, 2006, 42(12): 1–5 [译自: 林业科学] 相似文献
10.
Carbon storage of artificial forests in rehabilitated lands in the upper reaches of the Yellow River
Jianzhong Hu 《Frontiers of Forestry in China》2006,1(3):268-276
We studied 10-to 27-year-old artificial forests on rehabilitated lands in the upper reaches of the Yellow River with the objective
of comparing the carbon densities of various artificial and natural forests. Under artificial plantations, the vegetation
layer (including roots) had a mean carbon density of 111.3 t/hm2, the litter layer a density of 5.1 t/hm2, and the soil layer a density of 64.9 t/hm2. These values accounted for 28.6%, 13.8%, and 61.0% of their respective counterparts in the natural secondary forests under
the same site conditions in the region. The ratios of carbon density among vegetation, litter, and soil pools were 39.6:1.8:58.6
for artificial forests and 57.4:2.7:39.9 for natural forests. The carbon densities of the vegetation and litter layers increased
exponentially with forest age. The total carbon density ratios were also increasing gradually. Although the mean total carbon
density of the artificial forests in the rehabilitated lands was 281.2 t/hm2 in the experimental area, it accounted for only 41.5% of the carbon density of the natural secondary forests (677.4 t/hm2). The annual increase in total carbon density of artificial forests was as high as 15.2 t/hm2, which was 11.7% more than that of natural forests and 6.8 times higher than that (1.95 t/hm) of artificial forests in the
entire country as measured during 1994–1998. This indicates that growth and carbon storage capacity of artificial forests
in the rehabilitated lands were higher than those of forests on the barren hills and the secondary forests. We concluded that
the conversion project from croplands to forests and grasslands based on scientific principles is very important in the formation
of carbon sinks for reducing greenhouse effects.
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Translated from Journal of Beijing Forestry University, 2005, 27(6): 1–8 [译自: 北京林业大学学报, 2005, 27(6): 1–8] 相似文献
11.
Jing Yin Fan He Guoyu Qiu Kangning He Jinghui Tian Weiqiang Zhang Yujiu Xiong Shaohua Zhao Jianxin Liu 《Frontiers of Forestry in China》2009,4(3):351-357
The objectives of our study were to explore the relationship of leaf area and stand density and to find a convenient way to
measure stand leaf areas. During the 2004 growing season, from May to October, we used direct and indirect methods to measure
the seasonal variation of the leaf areas of tree and shrub species. The trees were from Robinia pseudoacacia stands of four densities (3333 plants/hm2, 1666 plants/hm2, 1111 plants/hm2, and 833 plants/hm2) and Platycladus orientalis stands of three densities (3333 plants/hm2, 1666 plants/hm2, and 1111 plants/hm2). The shrub species were Caragana korshinskii, Hippophae rhamnoides, and Amorpha fruticosa. Based on our survey data, empirical formulas for calculating leaf area were obtained by correlating leaf fresh weight, diameter
of base branches, and leaf areas. Our results show the following: 1) in September, the leaf area and leaf area index (LAI)
of trees (R. pseudoacacia and P. orientalis) reached their maximum values, with LAI peak values of 10.5 and 3.2, respectively. In August, the leaf area and LAI of shrubs
(C. korshinskii, H. rhamnoides, and A. fruticosa) reached their maximum values, with LAI peak values of 1.195, 1.123, and 1.882, respectively. 2) There is a statistically
significant power relation between leaf area and leaf fresh weight for R. pseudoacacia. There are significant linear relationships between leaf area and leaf fresh weight for P. orientalis, C. korshinskii, H. rhamnoides, and A. fruticosa. Moreover, there is also a significant power relation between leaf area and diameter of base branches for C. korshinskii. There are significant linear relations between leaf area and diameter of base branches of H. rhamnoides and A. fruticosa. 3) In the hills and gully regions of the Loess Plateau, the LAIs of R. pseudoacacia stand at different densities converged after the planted stands entered their fast growth stage. Their LAI do not seem to
be affected by its initial and current density. The same is true for P. orientalis stands. However, the leaf area of individual trees is negatively and linearly related with stand density. We conclude that,
in the hills and gully regions of the Loess Plateau, the bearing capacity of R. pseudoacacia and P. orientalis stands we studied have reached their maximum limitation, owing to restricted access to soil water. Therefore, in consideration
of improving the quality of single trees, a stand density not exceeding 833 and 1111 plants/hm2 is recommended for R. pseudoacacia and P. orientalis, respectively. In consideration of improving the quality of the entire stands, the density can be reduced even a little more.
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Translated from Journal of Plant Ecology (Chinese Version), 2008, 32 (2): 440–447 [译自: 植物生态学报] 相似文献
12.
Shanfeng He Lanlan Qiu Deming Jiang A. Lamusa Zhimin Liu Yongming Luo 《Frontiers of Forestry in China》2008,3(1):31-35
In the semi-arid Horqin sandy land of north China, Caragana microphylla, a leguminous shrub, is the dominant plant species and is widely used in vegetation reestablishment programs to stabilize
shifting sand. The sand-fixing effects of 6-and 11-year-old C. microphylla plantations were studied. The results showed that: 1) the wind velocity and sand transport rate in the plantation were less
than those in dunes; 2) the air temperature in the plantation was lower than those in dunes. Relative humidity was higher
and the soil temperature was lower, which benefits plant growth; 3) the physical and chemical characteristics of soil were
improved to some extent over age. The porosity and percentage of tiny sand (diameter 0.05–0.1 mm) and clay particle (diameter
< 0.05 mm) increased, bulk density in surface soil decreased, and saturated water-holding capacity improved. Organic C, total
N, available N and available K content increased gradually, and soil fertility was enhanced.
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Translated from Journal of Soil and Water Conservation, 2007, 21(1): 84–87 [译自: 水土保持学报] 相似文献
13.
We investigated the biomass, vertical distribution, and specific root length (SRL) of fine and small roots in a chronosequence
of Japanese cedar (Cryptomeria japonica D. Don) plantations in Nara Prefecture, central Japan. Roots were collected from soil blocks up to 50 cm in depth in five
plantations of differing age: 4, 15, 30, 41, and 88 years old. Fine-root biomass reached a maximum (639 g m−2) in the 15-year-old stand before canopy closure, decreased in the 30-year-old stand (422 g m−2), and thereafter was stable. Except in the 30-year-old stand, fine-root biomass increased in deeper soil layers as stand
age increased, and the depth at which the cumulative biomass of fine roots reached 90% exhibited a good allometric relationship
with mean stem diameter. Both root-length density (root length per unit soil volume) and SRL decreased with soil depth in
all stands, indicating that plants mainly acquire water and nutrients from shallow soils. The highest SRL was observed in
the 4-year-old stand, but the relationship between SRL and stand age was unclear in older stands. The SRL in surface soils
seemed to decrease with increases in root-length density, suggesting that branching of the fine-root system during development
is related to density-dependent processes rather than age. 相似文献
14.
[目的]研究5种不同密度林分土壤剖面养分含量的变化规律。[方法]以广西大青山37年生杉木密度试验林为研究对象,测定了A(1 667株·hm-2)、B(3 333株·hm-2)、C(5 000株·hm-2)、D(6 667株·hm-2)、E(10 000株·hm-2)5种密度下0 100 cm土层土壤养分含量。利用单因素方差分析和多重比较判断不同密度和不同土层土壤养分含量的差异。[结果]表明:(1)杉木人工成熟林大多数土层土壤有机质、全氮、碱解氮、全磷、有效性铁含量在A、B等低密度林分中最高,并且在0 30 cm的土壤中,随密度的增加表现出总体下降的变化趋势,而土壤pH值与全钾、速效钾随密度的增加而上升,交换性钙与交换性镁含量受密度影响不明显;(2)土壤有机质、全氮、碱解氮、有效磷、速效钾、交换性钙、交换性镁和有效性铁含量均随土层深度的增加而明显下降,0 30 cm表层土壤的降幅较大,密度对不同土壤深度养分含量的变化具有一定影响。[结论]初植密度对杉木人工成熟林土壤养分含量影响明显,低初植密度更有利于杉木人工林土壤肥力的长期维持,南亚热带杉木林密度对土壤养分的影响深度可达60 cm。 相似文献
15.
对北京九龙山油松、侧柏、黄栌3种纯林的枯落物层水文效应和土壤水分效应进行研究,结果表明:黄栌林分的枯落物总蓄积量最大,为13.15 t·hm-2,其次为油松和侧柏,分别为12.50、9.53 t·hm-2;黄栌的最大持水量和有效拦蓄量最大,分别为28.73、23.17 t·hm-2;侧柏的最小,分别为12.67、10.17 t·hm-2。未分解层和半分解层枯落物持水量分别在浸泡10 h后和8 h后达到饱和,二者的吸水速率均在浸泡2 h内最大,4 h后趋于平稳。不同层次枯落物持水量、吸水速率与浸泡时间均存在较好的函数关系;3个林地的土壤密度均值最大的为侧柏(1.30 g·cm-3),其次为油松和黄栌,分别为1.23、1.08 g·cm-3;黄栌的总孔隙度最大,为49.63%,其次为油松和侧柏,分别为49.49%、47.44%;侧柏林地的土壤有效持水量最大,为96.53 t·hm-2,其次为黄栌和油松,分别为88.23、69.00 t·hm-2。对入渗速率与入渗时间进行拟合分析,二者呈幂函数关系,其相关系数R2值均在0.90以上。 相似文献
16.
《Forest Ecology and Management》1999,124(1):1-12
We simulated loblolly pine (Pinus taeda L.) net canopy assimilation, using BIOMASS version 13.0, for the southeastern United States (1° latitude by 1° longitude grid cells) using a 44-year historical climate record, estimates of available water-holding capacity from a natural resource conservation soils database, and two contrasting leaf area indices (LAI) (low; peak LAI of 1.5 m2 m−2 projected, and high; 3.5 m2 m−2). Median (50th percentile) available water-holding capacity varied from 100 to 250 mm across the forest type for a normalized 1.25 m soil profile. Climate also varied considerably (growing season precipitation ranged from 200 to 1600 mm while mean growing season temperature ranged from 13° to 26°C). Net canopy assimilation ranged from 9.3 to 19.2 Mg C ha−1 a−1 for high LAI and the 95th percentile of available water-holding capacity simulations.We examined the influence of soil available water-holding capacity, and annual variation in temperature and precipitation, on net canopy assimilation for three cells of similar latitude. An asymptotic, hyperbolic relationship was found between the 44-year average net canopy assimilation and soil available water-holding capacity. Shallow soils had, naturally, low water-holding capacity (<100 mm) and, subsequently, low productivity. However, median available water-holding capacity (125–150 mm) was sufficient to maintain near maximum production potential in these cells.Simulations were also conduced to examine the direct affects of soil available water on photosynthesis (PN) and stomatal conductance (gS) on net canopy assimilation. In the absence of water limitations on PN and gS, net canopy assimilation increased by only 10% or less over most of the loblolly pine region (when compared to simulations for median available water-holding capacity with water influences in place). However, the production differences between high and low LAI, at the median soil available water-holding capacity, ranged from 30% to 60% across the loblolly pine range. Vapor pressure deficit was found to dramatically reduce productivity for stands of similar LAI, incident radiation, rainfall, and available water-holding capacity. Thus, these simulations suggest that, regionally, loblolly pine productivity may be more limited by low LAI than by soil available water-holding capacity (for soils of median available water-holding capacity or greater). In addition, high atmospheric forcing for water vapor will reduce net assimilation for regions of otherwise favorable available water and LAI. 相似文献
17.
Acacia mangium is a very fast growing species belonging to the family Leguminosae that has been introduced in the plantations in Bangladesh for its faster growth and wide range of adaptability. The present study aimed at development of growth and yield prediction models for the species using simultaneous equation method. Models were selected for the species to estimate stand dominant height, stand diameter, stand basal area per hectare and total volume yield per hectare. Paired t-test, 45-degree line test, percent absolute deviation and biological principle of stand development were used for the validation of chosen models. The results suggest that the models derived were statistically and biologically acceptable and could be satisfactorily used for stands of Acacia mangium of ages 4–7 yrs based on a base age of 6 yr. 相似文献
18.
[目的]研究了马尾松从幼龄林至成熟林生长序列中的土壤有机C、全N、全P含量及其生态化学计量特征,以丰富该区域马尾松生态系统生态化学计量学领域的基础研究。[方法]以广西凭祥4个林龄(6、16、23、35 a)马尾松人工林为研究对象,每个林龄选取3块林分,每个林分内设置一个400 m2的调查样地,按照0 20、20 40、4060 cm三层土层取样,采用不同林分土壤化学计量的对比实验测定土壤CNP,采用单因素方差分析的LSD法进行显著性检验。[结果]表明:4个林龄马尾松人工林0 20 cm土壤有机C、全N、全P含量分别为5.73 15.56、0.691.23、0.17 0.23 g·kg-1,是20 40 cm土层的1.51、1.31、1.06倍,40 60 cm土层的1.97、1.58、1.06倍。土壤有机C含量、全N含量均随林龄的递增先降低后增加,随土层加深持续降低;土壤全P含量在林龄和土层间均无显著性变化;林龄对土壤C∶N、N∶P有极显著的影响(P=0.001,P=0.000),土层对土壤C∶P、N∶P有显著性影响(P=0.000,P=0.014)。[结论]土壤有机C、全N含量从成熟林阶段开始回升;N在不同林龄间和不同土层间的变化是土壤N∶P变化的主要原因;土壤C∶N、C∶P主要受有机C的影响。 相似文献
19.
Zhenhong Wang Chengbo Yang Limei Yang Zizong Zhou Jing Rao Li Yuan Ju Li 《Frontiers of Forestry in China》2007,2(1):18-27
In recent years, the relationship between biodiversity and ecosystem stability, productivity, and other ecosystem functions
has been extensively studied by using theoretical approaches, experimental investigations, and observations in natural ecosystems;
however, results are controversial. For example, simple systems were more stable than complex systems in theoretical studies,
and higher productivity was observed in human-made ecosystems with poorer species composition, etc. The role of biodiversity
in the ecosystem, such as its influence on sustainability, stability, and productivity, is still not understood. Because accelerated
soil-erosion in various ecosystems has caused a decrease of primary productivity, a logical way used in the study of the relationship
between biodiversity and ecosystem function can be used to study the relationship between plant species diversity and soil
conservation. In addition, biodiversity is a product of evolutionary history, and soil erosion is a key factor controlling
the evolution of modern environment on the surface of the Earth. A study on the relationship between biodiversity and soil-erosion
processes could help us understand the environmental evolution of Earth.
Fifteen 10 m × 40 m standard runoff plots were established to measure surface runoff, soil erosion, and total P loss in different
secondary communities of semi-humid evergreen broad-leaved forests that varied in composition, diversity, and level of disturbance
and soil erosion. The following five communities were studied: AEI (Ass. Elsholtzia fruticosa + Imperata cylindrical), APMO (Ass. Pinus yunnanensis + Myrsine africana + Oplismenus compsitus), APLO (Ass. Pinus yunnanensis + Lithocarpus confines + Oplismenus compsitus), AEME (Ass. Eucalyptus smith + Myrsine africana + Eupatorium adenophorum), and ACKV (Ass. Cyclobalanopsis glaucoides + Keteleeria evelyniana + Viola duelouxii). Tree density, the diameter of the tree at breast height, and the hygroscopic volume of plant leaves were determined in
each plot.
Results indicated that surface runoff, soil erosion, and total P loss decreased as a power function with increase in plant
species diversity. Their average values for three years were 960.20 m3/(hm2 · year), 11.4 t/(hm2 · year), and 127.69 kg/(hm2 · year) in the plot with the lowest species diversity, and 75.55 m3/(hm2 · year), 0.28 t/(hm2 · year), and 4.71 kg/(hm2 · year) in the plot with the highest species diversity, 12, 50, and 25 times respectively lower compared with the lowest
species diversity plots. The coefficients of variation of surface runoff, soil erosion, and total P loss also followed a power
function with the increase of plant species diversity, and were 287.6, 534.21, and 315.47 respectively in the lowest species
diversity plot and 57.93, 187.94, and 59.2 in the highest species diversity plot. Enhanced soil conservation maintained greater
stability with increased plant species diversity. Plant individual density increased linearly and the canopy density and cross
section at breast height increased logarithmically with the increase of plant species diversity. The hydrological function
enhanced as the plant species diversity increased. There were obviously relationships between plant species diversity and
rainfall interception, coverage, and plant individual density, which was related to soil conservation functions in the five
forest communities.
The complex relationships between plant species diversity and the above-mentioned ecological processes indicated that plant
species diversity was an important factor influencing the interception of rainfall, reducing soil erosion and enhancing the
stability of soil conservation, but its mechanism is not known. This experiment showed that plant species diversity promoted
soil and nutrient conservation and ultimately lead to the increase of the primary productivity of the ecosystem, and was thus
a good way to study the relationship between biodiversity and ecosystem stability. Rainfall interception could be assessed
easily using the hygroscopic volume of plant leaves. Because there were strong correlations between plant species diversity
and soil conservation functions, the patterns of plant species diversity will show a certain level of predictability on the
interactions of life systems with surface processes of the Earth.
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Translated from Journal of Plant Ecology, 2006, 30(3): 392–403 [译自: 植物生态学报 相似文献
20.
Xingliang Liu Qinyan Ma Dongsheng Yang Zuoming Shi Yiming Su Shiqiang Zhou Shirong Liu Yupo Yang 《Frontiers of Forestry in China》2006,1(4):379-386
This study investigated root biomass and productivity in dominant populations in western Sichuan, China. A total of 4 plots
(Picea balfouriana plantation for 22 age in Maerkang, 9 trees, mean DBH of population for 10.4 cm and height for 10.5 m; Larix maxteriana plantation for 22 age in Wolong, 9 trees, mean DBH of population for 17.0 cm and height for 13.8 m; Abies fabri plantation for 35 age in Ebian, 18 trees, mean DBH of population for 14.1 cm and height for 11.9 m; Larix kaempferi plantation for 23 age in Miyaluo, 8 trees, mean DBH of population for 17.4 cm and height for 14.5 m; a 20 m×25 m plot located
on each of the 4 types in western Sichuan, China) were randomly selected and excavated to a depth of 60 cm for each of the
4 plantation types. To estimate the root biomass of an individual tree using D
2
H, an exponential model was selected with the highest coefficient ranging from 0.94 to 0.99. The total root biomass per hm2 varied among plantation population types following the order: L. kaempferi (37.832 t/hm2) > A. fabri (24.907 t/hm2) > L. maxteriana (18.320 t/hm2) > P. balfouriana (15.982 t/hm2). The biomass fractions of a given root size class compared to the total root biomass differed among plantation population
types. For all 4 studied plantation types, the majority of the roots were distributed in the top 40 cm of soil, e.g., 97.88%
for P. balfouriana population, 96.78% for L. maxteriana, 95.65% for A. fabri, and 99.72 for L. kaempferi population. The root biomass fractions distributed in the top 20 cm of soil were 77.13% for P. balfouriana, 77.13% for L. maxteriana, 65.02% for A. fabri and 80.66% for L. kaempferi, respectively. The root allocation in the 0–20, 20–40, and 40–60 cm soil layers gave ratios of 34:12:1 for P. balfouriana, 24:6:1 for L. maxteriana, 15:7:1 for A. fabri, and 64:4:1 for L. kaempferi populations. The root biomass density of dominant plantation population was 10.782 t/(hm2·m) for P. balfouriana, 8.230 t/hm2·m) for L. maxteriana, 24.546 t/(hm2·m) for A. fabri, and 13.211 t/(hm2·m) for L. kaempferi population, respectively. The root biomass productivity was found to be 0.57 t/(hm2·year) for P. balfouriana, 0.83 t/(hm2·year) for L. maxteriana, 0.71 t/(hm2·year) for A. fabri and 1.64 t/(hm2·year) for L. kaempferi population, respectively.
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Translated from Acta Ecologica Sinica, 2006, 26(2): 542–551 [译自: 生态学报, 2006, 26(2): 542–551] 相似文献