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1.
This study examined the biomass and carbon pools of the main ecosystem components in an age sequence of five Korean pine plantation forest stands in central Korea. The C contents in the tree and ground vegetation biomass, coarse woody debris, forest floor, and mineral soil were estimated by analyzing the C concentration of each component. The aboveground and total tree biomass increased with increasing stand age. The highest C concentration across this chronosequence was found in the tree branch while the lowest C concentration was found in the ground vegetation. The observed C contents for tree components, ground vegetation, and coarse woody debris were generally lower than the predicted C contents estimated from a biomass C factor of 0.5. Forest floor C content was age-independent. Total mineral soil C content appeared to decline initially after establishing Korean pine plantations and recover by the stand age of 35 years. Although aboveground tree biomass C content showed considerable accumulation with increasing age, the relative contribution of below ground C to total ecosystem C content varied substantially. These results suggest that successional development as temporal factor has a key role in estimating the C storage in Korean pine plantation forests.  相似文献   

2.
Patterns of biomass and carbon (C) storage distribution across Chinese pine (Pinus tabulaeformis) natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb), and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH) were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0–100 cm) were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha–1 for the young stand to 344.8 Mg·ha–1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha–1 in the middle-aged stand to 3.5 Mg·ha–1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha–1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha–1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale.  相似文献   

3.
The stock and structure of organic substances in the pine tree plantations on the overburden dumps of open-cut coal mines in Middle Siberia have been determined. It has been shown that the forming forest biogeocenoses differ from the natural phytocenoses and soils of the forest landscapes in the structure of the carbon pool and its distribution between the vegetation and soil components. In artificial forest ecosystems, the bulk of the plant component is accumulated in the aboveground part of the forest stand (40–59%). The aboveground grass cover contains only 0.1–1.4% of the total phytomass stock of the ecosystem. The annual accumulation of organic substances in the initial soils amounts to 0.28–1.45 t/ha.  相似文献   

4.
Keith  H.  Raison  R.J.  Jacobsen  K.L. 《Plant and Soil》1997,196(1):81-99
Pools and annual fluxes of carbon (C) were estimated for a mature Eucalyptus pauciflora (snowgum) forest with and without phosphorus (P) fertilizer addition to determine the effect of soil P availability on allocation of C in the stand. Aboveground biomass was estimated from allometric equations relating stem and branch diameters of individual trees to their biomass. Biomass production was calculated from annual increments in tree diameters and measurements of litterfall. Maintenance and construction respiration were calculated for each component using equations given by Ryan (1991a). Total belowground C flux was estimated from measurements of annual soil CO2 efflux less the C content of annual litterfall (assuming forest floor and soil C were at approximate steady state for the year that soil CO2 efflux was measured). The total C content of the standing biomass of the unfertilized stand was 138 t ha-1, with approximately 80% aboveground and 20% belowground. Forest floor C was 8.5 t ha-1. Soil C content (0–1 m) was 369 t ha-1 representing 70% of the total C pool in the ecosystem. Total gross annual C flux aboveground (biomass increment plus litterfall plus respiration) was 11.9 t ha-1 and gross flux belowground (coarse root increment plus fine root production plus root respiration) was 5.1 t ha-1. Total annual soil efflux was 7.1 t ha-1, of which 2.5 t ha-1 (35%) was contributed by litter decomposition.The short-term effect of changing the availability of P compared with C on allocation to aboveground versus belowground processes was estimated by comparing fertilized and unfertilized stands during the year after treatment. In the P-fertilized stand annual wood biomass increment increased by 30%, there was no evidence of change in canopy biomass, and belowground C allocation decreased by 19% relative to the unfertilized stand. Total annual C flux was 16.97 and 16.75 t ha-1 yr-1 and the ratio of below- to aboveground C allocation was 0.43 and 0.35 in the unfertilized and P-fertilized stands, respectively. Therefore, the major response of the forest stand to increased soil P availability appeared to be a shift in C allocation; with little change in total productivity. These results emphasise that both growth rate and allocation need to be estimated to predict changes in fluxes and storage of C in forests that may occur in response to disturbance or climate change.  相似文献   

5.
The distribution of tree biomass and the allocation of organic matter production were measured in an 11-yr-old Pinus caribaea plantation and a paired broadleaf secondary forest growing under the same climatic conditions. The pine plantation had significantly more mass aboveground than the secondary forest (94.9 vs 35.6 t ha-1 for biomass and 10.5 vs 5.0 t ha-1 for litter), whereas the secondary forest had significantly more fine roots (⩽2 mm diameter) than the pine plantation (10.5 and 1.0 t ha-1, respectively). Standing stock of dead fine roots was higher than aboveground litter in the secondary forest. In contrast, aboveground litter in pine was more than ten times higher than the dead root fraction. Both pine and secondary forests had similar total organic matter productions (19.2 and 19.4 t ha-1 yr-1, respectively) but structural allocation of that production was significantly different between the two forests; 44% of total production was allocated belowground in the secondary forest, whereas 94% was allocated aboveground in pine. The growth strategies represented by fast growth and large structural allocation aboveground, as for pine, and almost half the production allocated belowground, as for the secondary forest, illustrate equally successful, but contrasting growth strategies under the same climate, regardless of soil characteristics. The patterns of accumulation of organic matter in the soil profile indicated contrasting nutrient immobilization and mineralization sites and sources for soil organic matter formation.  相似文献   

6.
The carbon (C) and nitrogen (N) storage capabilities of Pinus densiflora in six different stand ages (10, 27, 30, 32, 44, and 71 years old) were investigated in Korea. Thirty sample trees were destructively harvested and 12 were excavated. Samples from the above and belowground tree components, coarse woody debris (CWD), forest floor, and mineral soil (0–30 cm) were collected. Tree biomass was highest in the 71-year-old stand (202.8 t ha−1) and lowest in the 10-year-old stand (18.4 t ha−1). C and N storage in the mineral soil was higher in the 71-year-old stand than in the other stands, mainly due to higher soil C and N concentrations. Consequently, the total ecosystem C and N storage (tree+forest floor+CWD+soil) was positively correlated with stand age: increasing from a minimum in the 10 year old stand (18.8 t C ha−1 and 1.3 t N ha−1) to a maximum in the 71-year-old stand (201.4 t C ha−1 and 8.5 t N ha−1). The total ecosystem C storage showed a similar sigmoidal pattern to that of tree C storage as a function of the age-sequence, while N storage in the CWD, forest floor and mineral soil showed no significant temporal trends. Our results provide important insights that will increase our understanding of C and N storage in P. densiflora stands and our ability to predict changes according to stand age in the region.  相似文献   

7.
广西主要树种(组)异速生长模型及森林生物量特征   总被引:5,自引:0,他引:5  
基于广西11类主要树种(组)5个龄组(245株样木、345块样地)的生物量实测调查,建立了各树种(组)的生物量优化异速生长模型,探讨广西森林生态系统总生物量及不同森林类型、不同龄组、不同层次的生物量组成与分配。结果表明:(1)广西11类树种(组)叶、枝、干、根、全株生物量(除了杉树叶、桉树叶生物量)、地上-地下、胸径-树高的优化回归模型均为幂函数,经t检验均达到显著水平(P0.05),其中11类树种(组)以全株生物量的模拟效果最好;(2)广西森林总生物量为1425.37 Tg,平均生物量为105.36 Mg/hm2,各森林类型总生物量为松树林(366.14 Tg)硬阔(291.08 Tg)软阔(239.75 Tg)石山林(165.51 Tg)杉木林(164.01 Tg)桉树林(99.55 Tg)栎类(46.34 Tg)八角林(20.21 Tg)油茶林(19.59 Tg)竹林(13.19 Tg),均随年龄的增加而增加,各层次生物量均以乔木层占绝对优势,所占比例为78.30%—97.47%,各龄组地上生物量均大于地下生物量;(3)考虑统计学与实际应用之间的平衡及异速生长模型的可解释量、回归系数的显著性,以胸径为变量的生物量模型能有效估算广西主要树种(组)各器官及总生物量;(4)优化筛选的广西各树种(组)的地上-地下优化异速生长模型及推算的地上-地下生物量比,对于估计广西森林地下生物量具有重要参考价值。  相似文献   

8.
We evaluated how three co‐occurring tree and four grassland species influence potentially harvestable biofuel stocks and above‐ and belowground carbon pools. After 5 years, the tree Pinus strobus had 6.5 times the amount of aboveground harvestable biomass as another tree Quercus ellipsoidalis and 10 times that of the grassland species. P. strobus accrued the largest total plant carbon pool (1375 g C m?2 or 394 g C m?2 yr), while Schizachyrium scoparium accrued the largest total plant carbon pool among the grassland species (421 g C m?2 or 137 g C m?2 yr). Quercus ellipsoidalis accrued 850 g C m?2, Q. macrocarpa 370 g C m?2, Poa pratensis 390 g C m?2, Solidago canadensis 132 g C m?2, and Lespedeza capitata 283 g C m?2. Only P. strobus and Q. ellipsoidalis significantly sequestered carbon during the experiment. Species differed in total ecosystem carbon accumulation from ?21.3 to +169.8 g C m?2 yr compared with the original soil carbon pool. Plant carbon gains with P. strobus were paralleled by a decrease of 16% in soil carbon and a nonsignificant decline of 9% for Q. ellipsoidalis. However, carbon allocation differed among species, with P. strobus allocating most aboveground in a disturbance prone aboveground pool, whereas Q. ellipsoidalis, allocated most carbon in less disturbance sensitive belowground biomass. These differences have strong implications for terrestrial carbon sequestration and potential biofuel production. For P. strobus, aboveground plant carbon harvest for biofuel would result in no net carbon sequestration as declines in soil carbon offset plant carbon gains. Conversely the harvest of Q. ellipsoidalis aboveground biomass would result in net sequestration of carbon belowground due to its high allocation belowground, but would yield lower amounts of aboveground biomass. Our results demonstrate that plant species can differentially impact ecosystem carbon pools and the distribution of carbon above and belowground.  相似文献   

9.
Increased fire activity within boreal forests could affect global terrestrial carbon (C) stocks by decreasing stand age or altering tree recruitment, leading to patterns of forest regrowth that differ from those of pre-fire stands. To improve our understanding of post-fire C accumulation patterns within boreal forests, we evaluated above- and belowground C pools within 17 Cajander larch (Larix cajanderi) stands of northeastern Siberia that varied in both years since fire and stand density. Early-successional stands (<20-year old) exhibited low larch recruitment, and consequently, low density, aboveground larch biomass, and aboveground net primary productivity (ANPPtree). Mid-successional stands (21- to 70-year old) were even-aged with considerable variability in stand density. High-density mid-successional stands had 21 times faster rates of ANPPtree than low-density stands (252 vs. 12?g?C?m?2?y?1) and 26 times more C in aboveground larch biomass (2,186 vs. 85?g?C?m?2). Density had little effect on total soil C pools. During late-succession (>70-year old), aboveground larch biomass, ANPPtree, and soil organic layer C pools increased with stand age. These stands were low density and multi-aged, containing both mature trees and new recruits. The rapid accumulation of aboveground larch biomass in high-density, mid-successional stands allowed them to obtain C stocks similar to those in much older low-density stands (~8,000?g?C?m?2). If fire frequency increases without altering stand density, landscape-level C storage could decline, but if larch density also increases, large aboveground C pools within high-density stands could compensate for a shorter successional cycle.  相似文献   

10.
How stand density and species richness affect carbon (C) storage and net primary productivity (NPP) changes with forest succession is poorly understood. We quantified the C storage of trees and the aboveground NPP in an early successional secondary birch forest (birch forest) and a late successional mixed broadleaf-Korean pine (Pinus koraiensis) forest (mixed forest) in northeastern China. We found that: 1) tree C storage in the mixed forest (120.3 Mg C ha?1) was significantly higher than that in the birch forest (78.5 Mg C ha?1), whereas the aboveground NPP was not different between the two forest types; and 2) only stand density had a positive linear relationship with tree C storage and aboveground NPP in the birch forest. In the mixed forest, both tree C storage and aboveground NPP were significantly affected by the combination of the stand density and species richness. The tree C storage to stand density and species richness relationships were hump-shaped. The aboveground NPP increased with increasing stand density, but its relationship to species richness was hump-shaped. We conclude that the effect of stand density and species richness on tree C storage and aboveground NPP was influenced by forest stand succession, and such effects should be considered in studying stand density- and species richness- ecosystem function (e.g., C storage and NPP) relationships in temperate forest ecosystems.  相似文献   

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