Stand height and cover type complement forest age structure as a biodiversity indicator in boreal and northern temperate forest management

Forest age structure is one of the main indicators of biodiversity in temperate and boreal forests worldwide. This indicator was mainly chosen for the conservation of a subset of rare or sensitive species related to the oldest age classes, not to capture variability across the entire biodiversity spectrum, but is often considered as such. In this study, we analysed alpha and beta diversity in temporary plots of western Quebec, Canada, to consider biodiversity indicators complementary to existing forest age structure targets. Our analysis revealed that considered individually, stand characteristics such as cover type and height are better predictors of changes in site-level contribution to tree beta diversity than age. We also show that plots belonging to different age classes can be similar in terms of tree alpha diversity. Height class was found to have a more significant impact on tree alpha diversity than expected: height was more important than age in coniferous forests, and in deciduous and mixedwood stands it frequently complemented age in explaining the observed diversity patterns. Our results suggest that forest age structure target levels should not be used as the sole indicator of ecosystem sustainability, and that some mature secondary stands can provide significant contributions to biodiversity. We propose that more efficient trade-offs between forest exploitation, ecosystem functioning and environmental conservation can be attained if: (i) forest age structure targets are complemented by cover type and stand height; or (ii) complementary biodiversity indicators of ecosystem sustainability are implemented.     

基于清查数据的福建省马尾松生物量转换和扩展因子估算差异解析——3种集成学习决策树模型的比较

生物量转换和扩展因子(BCEFs)是估算森林生物量碳储量普遍使用的重要参数.厘清BCEFs估算差异的来源,可降低森林生物量碳储量评估的不确定性.利用基于集成学习的决策树模型能够很好地解决BCEFs估算差异来源问题.然而,不同此类模型的对比研究目前尚未见报道.本研究以第8次国家森林资源清查福建省331块马尾松的固定样地数据作为材料,分别利用增强回归树(BRT)、随机森林(RF)和立体派(Cubist)模型分析BCEFs(包括地上和地下部分)估算差异的来源.结果表明: 研究区马尾松BCEFs呈右偏分布,平均值为0.69 t·m^-3,最小值为0.67 t·m^-3,最大值为0.71 t·m^-3.BRT、RF和Cubist模型对BCEFs的拟合和预测能力均很好,均能够解释92.8%以上的BCEFs变异.3种模型均给出了相同的前2个相对贡献率最大的自变量,为平均胸径和蓄积量.BCEFs随着平均胸径、蓄积量的增加呈逐渐减小的趋势.平均胸径、蓄积量、平均年龄和平均树高等林分特征因子对BCEFs的影响极大,而土壤因子和地形因子对BCEFs的影响均很小.在建立BCEFs模型时,利用平均胸径、蓄积量、平均年龄和平均树高等少量包含较多BCEFs预测信息的变量便能获取很好的预估精度.当应用固定BCEFs时,应选择在平均年龄、平均胸径以及蓄积等方面具有广泛代表性的样本计算BCEFs.     

Toward error analysis of large-scale forest carbon budgets

Quantification of forest carbon sources and sinks is an important part of national inventories of net greenhouse gas emissions. Several such forest carbon budgets have been constructed, but little effort has been made to analyse the sources of error and how these errors propagate to determine the overall uncertainty of projected carbon fluxes. We performed an error analysis for estimates of tree volume and volume change determined by repeated measurements of permanent sample plots for the South‐eastern United States as a step toward assessing errors in the carbon budget constructed by the USDA Forest Service. Error components recognized were: sampling error for sample plot selection; measurement error for tree height and diameter; and regression error for tree volume. Most of the propagated error in volume and volume change estimation was due to sampling error. Error estimates depended on the size of the area examined (single state to region) and the degree to which tree growth and recruit‐ment balanced mortality and harvesting. Approximate regional 95% confidence intervals were 3 455 073 000 ± 39 606 000 (1.1%) m³ for current growing‐stock volume, and 10 616 000 ± 4210 000 (39.7%) m³ years^?1 for growing‐stock volume change. These methods should be useful in further analysis of the sources of error and overall uncertainty in national efforts to quantify carbon fluxes associated with forests and land cover dynamics.     

Spatial analysis of structural and tree‐ring related parameters in a timberline forest in the Italian Alps

Abstract. We investigated the variability in spatial pattern of some structural, dendrochronological and dendroclimatological features of a mixed Larix decidua‐Pinus cembra forest at the timberline in the eastern Italian Alps at fine geographical and temporal scales. Forest structure variables such as stem diameter, tree height, age and tree‐ring related parameters (yearly growth index, mean sensitivity, first order autocorrelation and some dendroclimatic variables) have been compared at various scale levels. We observed that most of the variables show positive autocorrelated structures due to both forest dynamics and fine‐scale driving forces, probably related to microrelief. Spatial structure of yearly indexed radial growth appears sensitive to extreme climatic events. Secondary succession after past disturbances drives the forest towards a structure governed by a gap regeneration dynamics that seems to ensure the different requirements of the two main tree species present. Small spatial scale studies of forest structures, especially if integrated to dendro‐ecological data, seem an efficient tool to assess the disturbance regime and species sensitivity to environmental change.     

沙地樟子松林草木生长的研究

樟子松由于适应性强而被广泛引种到我国主要沙区．通过采用ＣｈａｍｐａｎＲｉｃｈａｒｄｓ生长模型,模拟了红花尔基和章古台两地樟子松的胸径、树高和材积的生长过程．天然樟子松林速生期持续时间长,数量成熟年龄为１００ａ,章古台人工林速生期持续时间短,数量成熟龄为４６ａ     

我国东北天然林保护工程区森林植被的碳储量

以东北天然林保护工程区森林生态系统为对象,通过对其主要森林类型进行调查,探讨天保工程经营区划对森林植被固碳现状的影响,并结合已有的东北林区生物量与蓄积量数据库,建立了东北林区主要树种组的生物量-蓄积量回归模型,然后以第7次森林资源清查为基础,对东北天保工程区森林植被碳储量进行估算,以期为全国森林生物量的估算和天保工程的评估提供参考。结果表明,不同经营区之间(重点公益林、一般公益林和商品林)森林植被碳密度的差异并不显著,这可能与天然林保护工程实施初期经营区划的标准、样地的选择以及天保工程实施过程中粗放的管理方式有关。东北天保工程区森林植被碳储量为1045 Tg C,占东北、内蒙古三省森林植被总碳储量的68%;工程区以天然林为主,占工程区总植被碳储量的97%。工程区森林植被平均碳密度为41 Mg/hm2,较东北、内蒙古三省平均植被碳密度高14%;工程区植被碳密度随林龄的增加逐渐增大,由幼龄林的13 Mg/hm2到过熟林的63 Mg/hm2。因此,继续加强天然林保护工程的实施,提高其林分质量,这对未来我国森林碳汇潜力的增加和森林的可持续发展都具有重要的意义。     

Climate warming feedback from mountain birch forest expansion: reduced albedo dominates carbon uptake

Expanding high‐elevation and high‐latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically based projection of mountain birch forest expansion in south‐central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase in summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land‐use history. In the future scenarios, forest cover increased from 12% to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow‐covered tundra areas. The positive climate feedback of high‐latitude and high‐elevation expanding forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts.     

内蒙古森林碳汇特征研究进展

内蒙古森林以其面积大、活立木总蓄积高成为全国森林的重要组成部分.本文以文献为基础,分析了近年来内蒙古森林及其组成部分的碳储量、碳密度、固碳速率和潜力.大部分研究以第六次森林清查数据为基础,利用材积与生物量之间的线性关系,得出内蒙古森林碳储量约为920 Tg C,占同期国家森林资源总碳储量的12%,年均增长率约为1.5%,平均碳密度约为43 t·hm^-2.森林碳储量和碳密度呈逐年增加趋势,其中,针阔叶混交林、樟子松林和白桦林固碳能力最高.间伐和皆伐等人类活动使森林碳储量明显降低.已有的碳汇特征研究很少涉及土壤部分,仅有少数研究指出土壤碳密度随林龄的增加而增加.关于森林生态系统固碳潜力的研究不够深入.建议今后在计算内蒙古森林生态系统碳储量时,加入土壤碳储量部分;利用异速生长方程计算碳储量时,将树种器官碳含量设为45%;建立更多优势树种的、包含根系生物量的异速生长方程;加强气候变化与生态系统固碳速率和潜力关系的研究.     

Continental estimates of forest cover and forest cover changes in the dry ecosystems of Africa between 1990 and 2000

Aim

This study provides regional estimates of forest cover in dry African ecoregions and the changes in forest cover that occurred there between 1990 and 2000, using a systematic sample of medium‐resolution satellite imagery which was processed consistently across the continent.

Location

The study area corresponds to the dry forests and woodlands of Africa between the humid forests and the semi‐arid regions. This area covers the Sudanian and Zambezian ecoregions.

Methods

A systematic sample of 1600 Landsat satellite imagery subsets, each 20 km × 20 km in size, were analysed for two reference years: 1990 and 2000. At each sample site and for both years, dense tree cover, open tree cover, other wooded land and other vegetation cover were identified from the analysis of satellite imagery, which comprised multidate segmentation and automatic classification steps followed by visual control by national forestry experts.

Results

Land cover and land‐cover changes were estimated at continental and ecoregion scales and compared with existing pan‐continental, regional and local studies. The overall accuracy of our land‐cover maps was estimated at 87%. Between 1990 and 2000, 3.3 million hectares (Mha) of dense tree cover, 5.8 Mha of open tree cover and 8.9 Mha of other wooded land were lost, with a further 3.9 Mha degraded from dense to open tree cover. These results are substantially lower than the 34 Mha of forest loss reported in the FAO's 2010 Global Forest Resources Assessment for the same period and area.

Main conclusions

Our method generates the first consistent and robust estimates of forest cover and change in dry Africa with known statistical precision at continental and ecoregion scales. These results reduce the uncertainty regarding vegetation cover and its dynamics in these previously poorly studied ecosystems and provide crucial information for both science and environmental policies.     

江西中南部红壤丘陵区主要造林树种碳固定估算

本文根据江西第6次森林清查小班数据,通过基于实地调查数据拟合的森林植被生物量与蓄积量的关系,估算了2003年江西中南部红壤丘陵区泰和县和兴国县主要人工造林树种马尾松、湿地松、杉木林的生物量和碳储量,并采用空间替代时间的方法,利用Logistic方程拟合了三个树种林龄与碳密度的曲线关系,估算了研究区1985-2002年的森林植被生物量和碳储量,分析了时空动态特征。结果表明：(1) 2003年研究区主要造林树种林分面积31.04?10⁴hm²,总生物量22.20Tg,总碳储量13.07TgC,平均碳密度42.36tC/hm²。(2) 1985、1994、2003年三个树种植被碳储量分别为4.91、11.41和13.07TgC,年均固碳量0.45 TgC.a^-1。(3) 海拔位于700-900m之间的树种平均碳密度最大,坡度位于25～35?之间的树种平均碳密度最大。森林植被碳密度总体上呈现随海拔高度的增加而增加,随坡度的增大而增大的分布。人工造林工程使江西中南部红壤丘陵区森林植被碳储量明显增加,合理的森林经营管理可以提高森林生态系统的固碳能力。     

Evaluating the effects of climate change on tree species abundance and distribution in the Italian peninsula

Question: What is the effect of climate change on tree species abundance and distribution in the Italian peninsula? Location: Italian peninsula. Methods: Regression tree analysis, Random Forest, generalized additive model and geostatistical methods were compared to identify the best model for quantifying the effect of climate change on tree species distribution and abundance. Future potential species distribution, richness, local colonization, local extinction and species turnover were modelled according to two scenarios (A2 and B1) for 2050 and 2080. Results: Robust Random Forest proved to be the best statistical model to predict the potential distribution of tree species abundance. Climate change could lead to a shift in tree species distribution towards higher altitudes and a reduction of forest cover. Pinus sylvestris and Tilia cordata may be considered at risk of local extinction, while the other species could find potential suitable areas at the cost of a rearrangement of forest community composition and increasing competition. Conclusions: Geographical and topographical regional characteristics can have a noticeable influence on the impact of predicted climate change on forest ecosystems within the Mediterranean basin. It would be highly beneficial to create a standardized and harmonized European forest inventory in order to evaluate, at high resolution, the effect of climate change on forest ecosystems, identify regional differences and develop specific adaptive management strategies and plans.     

西藏林芝地区森林碳储量、碳密度及其分布

利用林芝地区第六次二类森林资源清查数据,运用材积源生物量法和平均生物量法,结合不同树种的分子式含碳率,估算了林芝地区森林及其组分的碳储量、碳密度,并分析其分布特征.结果表明: 2004年,林芝地区森林碳储量为2.43×10⁸ t,森林平均碳密度为76.01 t·hm^-2,其中,林分碳储量>灌木林碳储量>疏林碳储量>散生木碳储量>竹林碳储量>四旁树碳储量,各林分类型碳储量在2.51×10⁵～1.27×10⁸ t,共计占总森林碳储量的92.0%,各林分类型的平均碳密度为103.16 t·hm^-2,其中冷杉林的碳储量和碳密度均最高.在区域分布上,森林碳储量由西北向东南递增,森林平均碳密度由西南向东北递增.林分碳储量以成、过熟林碳储量为主,而过熟林的碳密度在各龄级中最高.随着过熟林的增加,林芝地区森林碳储量将增加;但随着过熟林的死亡和分解,林芝地区森林碳储量将有减小趋势.     

浙江省森林生态系统碳储量及其分布特征

利用2011-2012年野外标准地实测资料, 结合第八次全国森林资源清查资料, 研究了浙江省森林生态系统碳储量及其分布特征。结果表明: 浙江省森林生态系统碳储量为602.73 Tg, 其中乔木层、灌草层、凋落物层和土壤层碳储量分别为122.88 Tg、16.73 Tg、11.36 Tg和451.76 Tg, 分别占生态系统碳储量的20.39%、2.78%、1.88%和74.95%; 在各森林类型中, 阔叶混交林碳储量为138.03 Tg, 所占比例最大(22.90%); 在森林各龄组中, 幼、中龄林约占浙江省森林生态系统碳储量的70.66%, 是碳储量的主要贡献者。浙江省森林生态系统平均碳密度为120.80 t·hm^-2, 乔木层、灌草层、凋落物层和土壤层碳密度分别为24.65 t·hm^-2、3.36 t·hm^-2、2.28 t·hm^-2和90.51 t·hm^-2。浙江省森林生态系统土壤层碳储量和生态系统碳储量呈极显著相关关系, 说明土壤层碳储量对浙江省森林生态系统碳储量贡献较大。浙江省天然林乔木层碳密度整体表现为过熟林>成熟林>近熟林>中龄林>幼龄林, 而人工林乔木层碳密度表现为过熟林>近熟林>成熟林>中龄林>幼龄林。浙江省幼、中龄林林分面积占比重较大, 占全省森林面积的76.76%, 若对现有森林进行更好的经营和管理, 可以增加浙江省森林的碳固存能力。     

Carbon storage and its distribution of forest ecosystems in Zhejiang Province,China

Aims
The concentration of CO₂ and other greenhouse gases in the atmosphere has considerably increased over last century and is set to rise further. Forest ecosystems play a key role in reducing CO₂ concentration in the atmosphere and mitigating global climate change. Our objective is to understand carbon storage and its distribution in forest ecosystems in Zhejiang Province, China.
Methods
By using the 8th forest resource inventory data and 2011-2012 field investigation data, we estimated carbon storage, density and its distribution in forest ecosystems of Zhejiang Province.
Important findings
The carbon storage of forest ecosystems in Zhejiang Province was 602.73 Tg, of which 122.88 Tg in tree layer, 16.73 Tg in shrub-herb layer, 11.36 Tg in litter layer and 451.76 Tg in soil layer accounting for 20.39%, 2.78%, 1.88% and 74.95% of the total carbon storage, respectively. The carbon storage of mixed broadleaved forests was 138.03 Tg which ranked the largest (22.90%) among all forest types. The young and middle aged forests which accounted for 70.66% of the total carbon storage were the main body of carbon storage in Zhejiang Province. The carbon density of forest ecosystems in Zhejiang Province was 120.80 t·hm^-2 and that in tree layer, shrub-herb layer, litter layer and soil layer were 24.65 t·hm^-2, 3.36 t·hm^-2, 2.28 t·hm^-2 and 90.51 t·hm^-2, respectively. The significant relationship between soil organic carbon storage and forest ecosystem carbon storage indicated that soil carbon played an important role in shaping forest ecosystem carbon density. Carbon density of tree layer increased with age in natural forests, but decreased in the order over-mature > near-mature > mature > middle-aged > young forest in plantations. The proportions of young and middle aged forests were larger than any other age classes. Thereby, the carbon storage of forest ecosystems in Zhejiang Province could be increased through a proper forest management.     

Analysis on carbon stock distribution patterns of forest ecosystems in Shaanxi Province

 为明晰陕西省森林生态系统碳储量分布格局, 基于2009年森林资源清查资料和2011年调查所得样地实测数据, 对陕西省森林生态系统碳储量、碳密度及其空间分布特征进行了研究分析。结果表明: 陕西省森林生态系统总碳储量为790.75 Tg, 土壤层、植被层和枯落物层碳储量分别占总碳储量的72.14%、26.52%和1.34%; 其中, 栎类碳储量在各森林类型中所占比重最大(44.17%), 中、幼龄林是陕西省森林生态系统碳储量的主要贡献者, 约占总碳储量的49%。陕西省森林生态系统平均碳密度为123.70 t·hm^–2, 土壤层最大, 枯落物层最小, 植被层居中; 碳密度均随龄级增加而升高, 同一龄级表现为天然林高于人工林生态系统。此外, 陕西省森林生态系统碳储量、碳密度分布格局不尽一致, 反映了森林覆盖面积及森林质量对碳储量的影响。未来应加强林地抚育管理水平, 增加造林再造林面积以增加碳储存, 应对全球气候变化。     

Potential for forest vegetation carbon storage in Fujian Province, China, determined from forest inventories

Carbon storage in forest vegetation of Fujian Province plays a significant role in the terrestrial carbon budget in China. The purposes of this study are: (1) to evaluate how the afforestation and reforestation programs established in Fujian Province influence carbon storage in forest ecosystems; (2) to assess the influence of tree species, forest age and ownership changes on vegetation carbon storage; and (3) to explore strategies for increasing vegetation carbon potentials. Data from seven Chinese Forest Resource Inventories and 5,059 separate sample plots collected between 1978 and 2008 were used to estimate vegetation carbon storage in the whole province. In addition, uncertainty analysis was conducted to provide the range of our estimations. Total forest vegetation carbon storage increased from 136.51 in 1978 to 229.31 Tg C in 2008, and the forest area increased from 855.27?×?10⁴ to 1,148.66?×?10⁴ ha, showing that the Fujian forests have a net vegetation carbon increase of 96.72 Tg C with an annual increase of 4.84 Tg C over the study period. Carbon storage varied with dominant forest species, forest age and forest ownership, suggesting that increases in vegetation carbon potentials can be achieved through selection of forest species and management of age structures. Implementation of afforestation and reforestation programs in Fujian Province over the past three decades has made a significant contribution to forest carbon storage. Vegetation carbon storage can be further increased by increasing the proportion of mature, broadleaved and state-owned forests.     

基于地理加权回归克里格模型的帽儿山地区森林碳储量空间分布

森林碳储量对于全球气候变化具有重要影响,以往的模型估算未考虑到模型残差的空间相关性和碳储量数据的非平稳性,影响模型的预测精度.本研究基于东北林业大学帽儿山实验林场的ETM+遥感影像数据和193块固定样地,利用地理加权克里格回归(GWRK)建立森林碳储量与遥感和地形因子的回归模型,同时对比最小二乘模型(OLS)、地理加权回归模型(GWR)的预测精度.结果表明: 对于帽儿山地区的森林碳储量估算,GWRK的平均绝对误差(MAE)、均方根误差(RMSE)低于OLS模型和GWR模型,GWRK模型的平均误差(ME)低于GWR模型,与OLS模型相近.GWRK模型的预测精度为83.2%,较OLS模型(73.7%)和GWR模型(77.3%)分别提高6%和10%,拟合精度明显提高,说明GWRK模型是森林碳储量估算的有效方法.利用GWRK模型预测的研究区森林碳储量平均值为70.31 t·hm^-2,在海拔较高的地区,森林碳储量值相对较高,说明海拔对其有较大影响.     

甘肃小陇山森林植被碳库及其分配特征

为准确估计甘肃小陇山林区森林植被的碳库大小,应用干烧法对该地区主要林分类型的13种乔木、14种灌木、10种草本植物的不同器官和7类林分的枯落物有机含碳率进行了测定,同时利用生物量标准地资料对8类林分的乔木层平均含碳率及森林植被的储碳密度和碳储量进行了估算,并分析了林分各组分的碳储量分配特征.结果表明:锐齿栎、油松、栓皮栎、白桦、红桦、日本落叶松、华山松、云杉、秦岭冷杉、水曲柳、大叶椋子木、五角枫、辽东栎13种乔木树种的器官平均含碳率范围为0.4501～0.5049,14种灌木和10种草本的器官平均含碳率分别为0.4446和0.3270,7类林分枯落物平均含碳率为0.4221.该地区8类林分的乔木层平均含碳率范围为0.4676～0.4976;小陇山林区森林植被层平均储碳密度为39.4254 t hm-2,总碳储量为13.3579 Tg.8类林分总碳储量分配中,乔木层占98.07%±0.73%,灌木层占1.38%4±0.43%,草本层占0.17%4±0.08%,枯落物层占0.37%±0.37%.甘肃小陇山8类林分乔木层的平均储碳密度值与我国及世界各地森林平均储碳密度的一些估计值基本接近.     

Evidence of incipient forest transition in southern Mexico

Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC). This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001) overall reduction of the mean rate of forest loss from 0.85% per year in the 1990-2000 period to 0.67% in the 2000-2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through reducing deforestation and enhancing forest growth.     

百山祖国家公园公益林碳储量及分配特征

探讨区域尺度的碳储量及其空间分布特征,评估优势树种(组)的固碳能力,可为生态系统保护措施的制定提供数据参考.百山祖国家公园保存了我国东南沿海最为典型完整的中亚热带森林生态系统,但百山祖公园碳密度和碳储量的特征还不清楚.本研究以百山祖国家公园公益林为对象,利用森林资源一类清查数据,基于浙江省各优势树种(组)的相容性生物量...