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1.
Three models for the prediction of bamboo culm length and two for culm volume were fitted from data of 303 guadua bamboo (Guadua angustifolia Kunth) culms. Data are from 101 temporary inventory plots systematically distributed over the coffee region of Colombia (inventory area about 1,029,525 ha). Linear and non-linear regression models were used, and the precision of the models was evaluated by cross-validation. The models were compared by studying the adjusted coefficient of determination, the bias, mean square error and Akaike’s information criterion and by the F-test that compares predicted and observed values. For culm length, the best fit showed models that included predictor variables related to stand characteristics such as quadratic mean diameter and number of culms per ha. For culm volume prediction, the inclusion of culm length improved the model significantly. For the simple form factor model, precision of prediction was least. The models developed are useful in facilitating the estimation of stand characteristics that are relevant for the silvicultural management of Guadua stands and also for the assessment of their environmental services (such as carbon sequestration).  相似文献   

2.
对福建省华安县瓜多竹开展引种试验,研究其生长情况、出笋期、出笋量、病虫害情况、越冬受冻情况及各器官生物量分配等。结果表明:瓜多竹一年四季均有出笋,4月下旬至8月下旬出笋最多;新长竹子的竹高和地径均随竹龄增长而增大,竹林栽植第3年可逐渐郁闭成林;瓜多竹生物量大,竹材产量高,其地上部分干生物量占总生物量的77.15%~83.58%,其中以竹秆所占生物量比例最大,为58.26%~71.16%;瓜多竹长势高,根浅,容易被风吹倒,无明显病虫害影响,但受寒冷低温天气影响大,建议在试验地以南、受台风影响较少的地区进行引种栽培。  相似文献   

3.
Tropical forests are the world’s largest terrestrial storehouses of carbon and are recognized as rich, diverse and highly productive ecosystems. The present study was conducted to characterize the land use, diversity and biomass of tropical forest in Western Ghat of Maharashtra State in India through satellite remote sensing and GIS. The study has been designed and implemented to promote analysis on Western Ghat biodiversity resources including trees, shrubs and herbs based on inventorying, monitoring and mapping. Field measured biomass is integrated with spectral responses of various bands and indices of the Landsat TM satellite image for estimation of above-ground biomass in a 36,046 km2 area of relic forest in the Central Western Ghat. The above-ground biomass from field-based inventory varied from 30.2 to 151.1 ton/ha in moist deciduous forest, 9.2–99.1 ton/ha in dry deciduous forest, 42.1–158.6 ton/ha in semi-evergreen forest, and 160.9–271 ton/ha in evergreen forest. The total above-ground biomass of the study area was estimated to be 95.2 M tons. A regression equation between field above-ground biomass and a Normalized Difference Vegetation Index was used for spectral modeling to estimate and prepare the above-ground biomass map in the region. A total 120 plant species in 81 genera and 31 families were identified in the study area. This study emphasizes the importance of relic forests for their biodiversity, carbon sequestration and total biomass.  相似文献   

4.
We used thermal images of bamboo culms of Guadua angustifolia Kunth to analyze the relationship between culm surface temperature and maturity, driven by the hypothesis that young culms may exhibit lower surface temperatures than old ones. The culm surface temperature shows small but constant differences between three age classes of 1, 2, and 3 years. Our findings indicate that surface temperature may be applied as an additional indicator to support the determination of maturity of guadua culms besides the visual assessment of the culms.  相似文献   

5.
The United Nations Framework Convention on Climate Change (UNFCCC) requires reporting net carbon stock changes and anthropogenic greenhouse gas emissions, including those related to forests. This paper describes the status of carbon stocks in sub tropical forests of Pakistan. There are two major sub types in subtropical forests of Pakistan viz a viz Subtropical Chir Pine and Subtropical broad leaved forests. A network of sample plots was laid out in four selected site. Two sites were selected from sub tropical Chir Pine (Pinus roxburghii) forests and two from Subtropical broadleaved forests. Measurement and data acquisition protocols were developed specifically for the inventory carried out from 2005 to 2010. In total 261 plots (each of 1ha.) were established. Estimation of diameter, basal area, height, volume and biomass was carried out to estimate carbon stocks in each of the four carbon pools of above-and below-ground live biomass. Soil carbon stocks were also determined by doing soil sampling. In mature (~100 years old) pine forest stand at Ghoragali and Lehterar sites, a mean basal area of 30.38 and 26.11 m2·ha-1 represented mean volume of 243 and 197 m3·ha-1,respectively. The average biomass (t·ha-1) was 237 in Ghoragali site and 186 t·ha-1 in Lehterar site, which is equal to 128 and 100 t C ha-1 including soil C. However, on average basis both the forests have 114.5± 2.26 t·ha-1 of carbon stock which comprises of 92% in tree biomass and only 8% inthe top soils. In mixed broadleaved evergreen forests a mean basal area(m2·ha-1) was 3.06 at Kherimurat with stem volume of 12.86 and 2.65 at Sohawa with stem volume of 11.40 m3·ha-1. The average upper and understorey biomass (t·ha-1) was 50.93 in Kherimurat site and 40.43 t·ha-1 in Sohawa site, which is equal to 31.18 and 24.36 t C ha-1 including soil Cstocks. This study provides a protocol and valuable baseline data for monitoring biomass and carbon stocks in Pakistan’s managed and unmanaged sub-tropical forests.  相似文献   

6.
We used thermal images of bamboo culms of Guadua angustifolia Kunth to analyze the relationship between culm surface temperature and maturity, driven by the hypothesis that young culms may exhibit lower surface temperatures than old ones. The culm surface temperature shows small but constant differences between three age classes of 1, 2, and 3 years. Our findings indicate that surface temperature may be applied as an additional indicator to support the determination of maturity of guadua culms besides the visual assessment of the culms.  相似文献   

7.
对传统的模拟测算法进行改进,以露水河林业局东升林场森林资源小班数据库为基础,测算了"十二五"期间商品林的合理采伐量,并模拟了在此采伐影响下森林资源动态变化。结果表明:经过30年的采伐,成熟林和过熟林面积之和占商品林的比例由41.62%调整到42.02%,成熟林面积大幅度增加,过熟林面积大幅度减少,森林资源结构得到优化;经过前5年的采伐,商品林蓄积由189.14万m3增为193.29万m3,森林资源消耗量低于生长量;每公顷蓄积由起初的134.85m3增加到137.80 m3;前5年合理年均采伐面积为182.42hm2,年均合理采伐蓄积为3.59万m3,可作为"十二五"期间调整采伐限额的依据。  相似文献   

8.
This study assessed the net above-ground carbon stock in six community forests in the Dolakha district, Nepal. A survey was conducted of above-ground timber species, using random sampling. A tree-ring chronology for Pinus roxburghii was created to construct a growth model representative of the various mainly-pine species. The allometric model combined with tree ring analysis was used to estimate carbon stock and annual growth in the above-ground tree biomass. The out-take of forest biomass for construction material and fuelwood was estimated on the basis of interviews and official records of community forest user groups. The average annual carbon increment of the community forests was 2.19 ton/ha, and the average annual carbon out-take of timber and fuelwood was 0.25 ton/ha. The net average carbon balance of 1.94 ton/ha was equivalent to 117.44 tons of carbon per community forest annually. All the community forests were actively managed leading to a sustainable forest institution, which acts as a carbon sink. It is concluded that community forests have the potential to reduce emissions by avoiding deforestation and forest degradation, enhance forest carbon sink and improve livelihoods for local communities.  相似文献   

9.
研究了4种伐桩处理强度(0株/hm2、225株/hm2、450株/hm2、675株/hm2)对毛竹林生产力的影响。结果表明:伐桩处理可以显著提高毛竹用材林的生产力和竹材质量;随伐桩处理强度加大,新竹生物量、新竹质量呈稳定提高的趋势;伐桩处理强度为675株/hm2的处理效果优于其他处理强度;在伐桩处理强度为675株/hm2的毛竹林中,新竹生物量高达35.4 t/hm2,较伐桩未处理林地提高了27.57%,大径级(DBH > 10 cm)新竹密度是伐桩未处理林地的1.43倍,新竹胸高处节间长度比伐桩未处理林地增加1.8 cm。此外,伐桩处理能显著提高中、小径级新竹的品质,继而提高毛竹材用林培育的整体效益。  相似文献   

10.
ABSTRACT

Planning a forest inventory comprises making decisions related to the sampling strategy: cluster configuration, sample size and sample allocation within the survey area. Cluster configuration includes deciding on the number of sample plots within the cluster and distances between them. Available resources set the limit for field work in terms of man-days. If the time consumption for measurements is known, the sample size can be determined under the constraint. In this study, we simulated the second phase of inventory sampling with fixed time resources by replicating sample selection with a spatially balanced sampling utilizing local pivotal method (LPM) for different cluster configurations to find the most efficient. As a result, the temporary cluster configuration was changed from 9 to 5-sample plot configuration in a pilot inventory. Further, the sample selection was performed with LPM having total growing stock volume and broadleaf volume proportion as auxiliary information. The pilot results were aligned with the time series in respect to forest area and total growing stock volume, but in tree species groups deviations were observed in growing stock volume. A more comprehensive optimization should include the travelling routes, the plot-to-plot distances and the plot design. In any case, the result is region specific.  相似文献   

11.
The overall objective of this study was to combine national forest inventory data and remotely sensed data to produce pan-European maps on growing stock and above-ground woody biomass for the two species groups “broadleaves” and “conifers”. An automatic up-scaling approach making use of satellite remote sensing data and field measurement data was applied for EU-wide mapping of growing stock and above-ground biomass in forests. The approach is based on sampling and allows the direct combination of data with different measurement units such as forest inventory plot data and satellite remote sensing data. For the classification, data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were used. Comprehensive field measurement data from national forest inventories for 98,979 locations from 16 countries were used for which tree species and growing stock estimates were available. The classification results were evaluated by comparison with regional estimates derived independently from the classification from national forest inventories. The validation at the regional level shows a high correlation between the classification results and the field based estimates with correlation coefficient r = 0.96 for coniferous, r = 0.94 for broadleaved and r = 0.97 for total growing stock per hectare. The mean absolute error of the estimations is 25 m3/ha for coniferous, 20 m3/ha for broadleaved and 25 m3/ha for total growing stock per hectare. Biomass conversion and expansion factors were applied to convert the growing stock classification results to carbon stock in above-ground biomass. As results of the classification, coniferous and broadleaved growing stock as well as carbon stock of the above-ground biomass is mapped on a wall-to-wall basis with a spatial resolution of 500 m × 500 m per grid cell. The mapped area is 5 million km2, of which 2 million km2 are forests, and covers the whole European Union, the EFTA countries, the Balkans, Belarus, the Ukraine, Moldova, Armenia, Azerbaijan, Georgia and Turkey.  相似文献   

12.
Abstract

This paper presents estimations of aboveground tree biomass (combined for boles and branches) in Nepal's Schima-Castanopsisdominated warm-temperate forests. The biomass estimations are presented for five forest stands purposively sampled in a larger study to represent different harvesting intensities. Two categories of biomass estimates are provided: (1) for living trees that are standing, and (2) for cut trees that have been removed. Biomass of standing trees were estimated by using diameter at breast height (dbh) and total height measurements as predictor variables in appropriate regression models. Biomass of cut trees were estimated in two steps: measurements of stump diameters and heights were used first to predict dbh and total heights of cut trees; these values were then regressed to obtain biomass estimates for the missing trees. Data were gathered from 2,361 live trees and 2,962 stumps in 170 sample plots across the five forest stands. Estimates of mean standing-alive biomass ranged from a minimum of 16 ton/ha in the severely disturbed forest to a maximum of 479 ton/ha in a relatively undisturbed (reference) forest. Estimates of mean cut biomass ranged from a minimum of 24 ton/ha in a second reference forest to a maximum of 183 ton/ha in the severely disturbed forest. The biomass estimates in the relatively-undisturbed, reference forests are well above the 95% upper confidence interval of the global mean. Similar findings of high productivity have been reported for temperate forests of the Central Himalaya in India and Eastern Himalaya in Sik-kim. The findings of this study in the Nepalese Central Himalaya support the conclusion that productivity potential is high in the temperate Himalayan forests. The study's findings and methodology should be useful for preliminary development of guidelines in the region to regulate forest biomass growth, yield, and harvest.  相似文献   

13.
The hollow cylindrical culm is one of the most remarkable morphological characters of most bamboo species. In relation to its hollow structure, there are two different attributes of the culm volume in bamboo: the apparent culm volume(v_a: the total culm volume including the hollow portion) and the woody culm volume(v_w: the volume of the woody walls of the culm). The ratio of v_w to v_a is defined as the reduction factor for culm volume(f_v).The quantity f_v is useful to quantify the biomass resources of bamboo culms as well as to evaluate the carbon stock of bamboo forests. However, the direct measurement of f_v requires destructive sampling, which consumes time and labor. Hence, an alternative method for obtaining f_v is desired. In this study, we examined f_v in five species of the genus Phyllostachys and proposed alternative methods to estimate f_v. Our data showed that f_v varied by species, some of which exhibited a dependency of f_v on culm sizes. These findings indicate that the intraspecific and interspecific variation in f_v should be considered carefully when converting v_a into v_w by f_v. Based on our results, we propose here six approaches for predicting f_v and we discuss their advantages and disadvantages. Our results are intended to facilitate evaluation of the carbon sequestration capacity of bamboo forests and the commercial utilization of bamboo culms.  相似文献   

14.
海南粗榧早期生长特性及栽培前景   总被引：3，自引：0，他引：3       下载免费PDF全文
  相似文献   

15.
不同密度山地速生工业原料林生物量的研究   总被引：1，自引：0，他引：1  
通过对4年生马褂木、邓恩桉、杜英3个树种不同密度条件下山地林分生物量的调查分析,结果表明:①4年生林分平均胸径5.08 cm,树高4.96 m,蓄积25.52 m3/hm2;平均单株生物量4.18 kg,其中树干2.95 kg,树皮0.36 kg,树枝0.73 kg,树叶0.20 kg;林分平均总生物量达到16.98 t/hm2,其中树干10.43 t/hm2,树皮1.29 t/hm2,树枝2.25 t/hm2,树叶0.71 t/hm2,凋落物2.53 t/hm2;②不同密度不同树种的林分生物量存在极显著差异,1.0 m×1.8 m密度极显著大于其它密度,马褂木极显著大于其它树种.1.0 m × 1.8 m密度的马褂木林分生物量达到41.71t/hm2;极显著大于其它林分,可以作为山地短轮伐期工业原料林的主要经营模式;③在空间分布上,山地工业原料林单株生物量由基部向上逐渐减少,呈塔形分布,树干和树皮生物量主要集中在树体的1/2树高以下,枝叶主要集中在中间区段,马褂木在3～6 m树高处,邓恩桉在3～5 m树高处,杜英在1～4 m树高处,是整个林分光合作用的主要层面.  相似文献   

16.
The African tulip tree, Spathodea campanulata, the most common tree in Puerto Rico, forms novel forest types with mixtures of native and other introduced tree species. Novel forests increase in area in response to human activity and there is no information about their biomass accumulation and nutrient cycling. We established allometric relationships and chemically analyzed plant parts of African tulip trees to determine the concentration and standing stock of chemical elements (C, N, P, K, Ca, Mg, S, Mn, Al, Fe, Na), and ash. Trees ranged in diameter at breast height from 8 to 85 cm and in height from 8.8 to 28 m. The concentrations of N, P, K, and Ca in leaves of the African tulip tree were similar to those of the native pioneer Cecropia schreberiana and higher than those of mature forest tree species in Puerto Rico. The over bark wood volume of African tulip trees in nine forest stands where it was dominant ranged from 163 to 849 m3/ha. Aboveground biomass ranged from 60 to 296 Mg/ha, and N and P stocks ranged from 190 to 988 and 32 to 137 kg/ha, respectively. Novel forests on abandoned agricultural lands can store more biomass and elements than native and plantation forest stands of similar age.  相似文献   

17.
近自然森林经营发源于德国巴伐利亚州,是当今国际公认的一种先进的森林经营方法。以德国巴伐利亚州4次森林资源连续清查成果为依据,从森林结构、枯木状况、森林近自然度、森林蓄积量4个方面对近自然森林经营成效进行分析评价。结果表明,1971—2012年的41年间,巴伐利亚州阔叶树种占比由22%提高到35.7%,针阔混交林和阔叶混交林已占乔木林面积的64.1%,复层林已占乔木林面积的77.4%,森林年龄结构基本实现了均衡分布;林内枯木数量达22 m3/hm2,为野生动物提供了栖息场所和营养来源;自然林和近自然林已占乔木林面积的42.6%,比德国全境高6.8个百分点;单位面积森林蓄积量396 m3/hm2,在全球处于领先地位。建议我国在营造林工程项目中加大近自然森林经营的推广应用力度,建好示范样板,并进一步探索近自然森林经营的技术和方法。  相似文献   

18.
云南省森林生物量与生产力研究   总被引：22，自引：0，他引：22  
森林是陆地生态系统的主体,生物量是反映森林生态系统功能的重要指标.通过利用最新的(2002年)森林资源清查数据,以生物量与蓄积量之间的关系模型为基础,对云南省的森林生物量及生产力进行了估计,为碳汇研究及森林生态系统评价提供重要依据.  相似文献   

19.
江苏省森林资源现状与特点分析   总被引：1，自引：0，他引：1  
森林资源二类调查是获取各基层单位森林资源现状与分布的主要方法,根据江苏省2009年森林资源二类调查结果,笔者通过提取各类林地、林木、林种、乔木林、竹林和灌木林的组成及分布等森林资源主要数据,并对单位面积蓄积、单位面积株数和树种结构等因子进行了对比分析,客观地反映了江苏森林资源快速增加、幼中龄林占优势地位、非公有制林业快...  相似文献   

20.
文章以甘肃省森林资源连续清查和统计数据为数据基础,采用统计分析的方法,对 40 年来 甘肃省森林资源动态变化进行了分析研究,结果表明：从 1975 年到 2016 年,全省林地面积由 630.87 万 hm2 增加到 1 046.35 万 hm2 ,增长 65.9%;有林地面积由 186.83 万 hm2 增加到 263.89 万 hm2 ,增长 41.2%;森林面积（含国家特别规定灌木林）由 2006 年的 470.67 万 hm2 增加到 2016 年的 509.73 万 hm2, 增长 8.3%;森林活立木蓄积量由 1.96 亿 m3 增长到 2.84 亿 m3 ,增长 45.1%。森林面积蓄积“双增”幅 度较大。全省乔木林每公顷蓄积量由 1975 年的 99.31m3 / hm2 微降到 2016 年的 95.45 m3 /hm2 ,下降 4.1%, 森林质量较低。同时乔木林树种、林龄结构不够合理。采用回归分析预估,到 2035 年和 2050 年,森林 面积分别达到 639.15 万 hm2 和 742.68 万 hm2 ,森林覆盖率达到 14.21% 和 16.52%,乔木林蓄积量达到 3.2 亿 m3 和 4.1 亿 m3 ,活立木蓄积量达到 3.6 亿 m3 和 4.5 亿 m3。  相似文献   

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