Average Diameter At Breast Height Research Articles

Comparison of stand characteristic parameters and biomass estimations from light detection and ranging and structure-from-motion point clouds

The accurate estimation and inversion of stand characteristic parameters and biomass is the premise for the evaluation of forest productivity, forest ecosystem carbon storage, and ecological forest service capacity. The horizontal accuracies of structure from motion (SfM) and light detection and ranging (LiDAR) point clouds were identical, whereas the descriptions of the upper canopy indices were similar ( R = 0.91 to 0.93). However, the descriptions of the lower canopy indices and vertical structure variables were different based on comparisons of the two point cloud types in the same region. Variables that described the vertical structure of the canopy in the SfM point clouds were much less important in the factor estimation models, exhibiting high correlations with basal area and volume. The factor estimation models with high correlations with tree height and diameter at breast height (DBH) exhibited similar importance for LiDAR variables. LiDAR ( R 2 = 0.515 to 0.895) was superior to SfM ( R 2 = 0.63 to 0.835) in estimating the same parameters, particularly those with high correlations with vertical structures. The combination of unmanned aerial vehicle aerial photogrammetry and LiDAR technology might enable the estimation of stand characteristic parameters and the inversion of biomass, as well as the estimation of characteristic parameters such as Lorey’s H and DBH, which are highly sensitive for large datasets. The LiDAR and SfM model outcomes were comparable. We found that the model outcomes exhibited the greatest differences for volume (ΔrRMSE % = 13.94 % ) and the lowest for average DBH (ΔrRMSE = 0.8 % )

封育年限对毛竹林群落结构和林下植物多样性的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 封育年限对毛竹林群落结构和林下植物多样性的影响 DOI: 10.5846/stxb201809282120 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31700540） Effects of exclosure term on community structure and undergrowth diversity of Phyllostachys pubescens Author: Affiliation: Fund Project: The National Natural Science Foundation of China 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探讨自然封育对毛竹林群落结构和林下植物多样性的影响，采用空间代替时间的方法，以浙江省杭州市余杭区常规经营（0年）和不同封育年限（10，20，30年）的毛竹林为对象，对毛竹林分结构和林下植物多样性进行了全面研究。结果表明：随着封育年限的延长，竹林密度增大，胸径变小；封育毛竹林中2度以上活立竹的密度显著高于常规经营（P<0.05），枯立竹的密度随着封育年限的延长而显著增加（P<0.05）；封育20年后的2度以上活立竹和枯立竹的胸径显著减小（P<0.05）。封育0，10，20，30年的毛竹林下灌木种类分别为68，35，58，77种，而草本植物种类则分别为64，23，31，44种。封育10年的林下灌木的Simpson指数显著低于其他林分（P<0.05），封育20年后的Shannon-Wiener指数显著高于前期年份（P<0.05），封育显著提高了Pielou指数（P<0.05）；封育显著降低了草本植物的Simpson指数（P<0.05），常规经营林下草本多样性指数Shannon-Wiener显著高于封育20年后的林分（P<0.05），封育10年的林下草本均匀度指数Pielou显著高于其他林分（P<0.05）。 Abstract:To explore the effects of natural exclosure on the community structure of the moso bamboo forest and the diversity of understory plants, two types of moso bamboo forest (human-manage forest and natural exclosure forest) were chosen in Yuhang District, Hangzhou City, using the method of space-for-time. In this study, 4 different plots (0 years, 10 years, 20 years, and 30 years) were set up, according to the age of natural exclosure. The culm density, diameter at breast height (DBH), and understory vegetation types etc. were investigated in the field survey. The results indicated that the culm density of bamboos increased gradually with increase of exclosure age, while the average DBH of bamboo decreased significantly. The density of ≥ 2° bamboo of natural-exclosure moso bamboo forest was significantly higher than that of the intensive-managed forest (P<0.05). The density of dead bamboo increased significantly with the extension of exclosure period (P<0.05). The DBH of ≥ 2° old bamboo and dead bamboo started to decrease significantly after 20 years of natural exclosure. The species of shrubs under the moso bamboo forest with 0, 10, 20, and 30 years of natural exclosure were 68, 35, 58, 77, respectively, while the herbaceous species were 64, 23, 31, and 44, respectively. The Simpson index of shrubs with 10 years of natural exclosure was significantly lower than that of other years (P<0.05). The Shannon-Wiener index after 20 years was significantly higher than that of the early year (P<0.05). The natural exclosure can help to increase the index of Pielou (P<0.05). The Simpson index of the herbaceous plants decreased in the natural exclosure forest (P<0.05). The Shannon-Wiener index of intensive-managed forest was significantly higher than that of 20 years (P<0.05), and the Pielou index of 10 years was significantly higher than the other years (P< 0.05). 参考文献 相似文献 引证文献

Human activities outcomes on the composition of woody plant species of Ngarama Southern Forest Reserve in Kilwa District, Tanzania

Abstract. Jilala ZJ, Mwakalukwa EE, Chamshama SAO. 2019. Human activities outcomes on the composition of woody plant species of Ngarama Southern Forest Reserve in Kilwa District, Tanzania. Asian J Ethnobiol 2: 108-118. This study evaluated the effects of human activities on the composition of woody plant species of the Ngarama Southern Forest Reserve (NSFR) in Kilwa District, Tanzania. Vegetation research was conducted in 40 systematically arranged rectangular test plots, aligned in five transepts over 2,070 ha forest. Information recorded in each plot included: species name, diameter at breast height (DBH), the height of selected timber species with a diameter ? 5 cm, and various indicators of human disturbance. Landsat TM and ETM+ images from 1995, 2000, and 2011 were used to locate and quantify the land cover change in the NSFR over the past 20 years. Inventory data was analyzed using Microsoft Excel and R software, while Landsat images were analyzed using the academic software ILWIS 3.0. About 126 plant species belonging to 34 families have been identified. Trees contributed 63% (28 families), and shrubs 37% (17 families). The Shannon-Wiener index and Simpson's diversity indices were 3.95 and 0.03, respectively. In addition, a mean stem density of 667 ± 19 stems ha-1 and a basal area of ??13.11 ± 0.34 m2 ha-1 were obtained. Twenty-three stumps (7 ± 3 ha-1 stems) with a mean baseline area of ??0.24 ± 0.09 m2 ha-1 stumps were removed, indicating ongoing anthropogenic disturbances in the forest. Other indicators of disturbance recorded were damage from fire (50%), paths / roads (13%), silage (8%), lumber/planks/pile harvesting (8%), cultivation (5%) and logging ( 8%). Although NSFR has a decent species richness and is well-diversified, there has been a consistently negative change in forest cover concerning low trunk density, average tree height, average DBH, and basal area, indicative of anthropogenic disturbance. Conservation measures are recommended to improve governance and accountability regarding accountability for intensive forest resource management.

Components of Tree Biomass in an Integrated Crop-Livestock-Forest System

Aims: This study performed the adjustment of volumetric models, and determined the biomass of Eucalyptus grandis x Eucalyptus urophylla hybrid cultivated in a crop-livestock-forest integration system (CLF).&#x0D; Study Design: The experimental area consists of a crop-livestock-forest integration system where trees are hybrids clones of seven year old Eucalyptus grandis x Eucalyptus urophylla.&#x0D; Place and Duration of Study: This work was carried out at Fazenda Santa Brígida, Ipameri, Goiás (Brazil).&#x0D; Methodology: A forest inventory of the area was carried out in October 2015 when the tree component was fully developed. Diameter at breast height (DBH) (at 1.30 m) and total height (H) of trees were measured in the field and categorized according to 4 classes. Afterwards, 12 trees were felled, which were cubed and compartmentalized to determine the volume and biomass of their components. The volumetric models developed by Schumacher &amp; Hall and Ogaya were applied to obtain determination coefficients.&#x0D; Results: The average DBH was 18.28 cm and the average H was 23.47 m. The highest volumes of wood were observed in the diametric classes that presented the largest number of individuals, however in the class of higher DBH an average individual volume of 0.36 m3 of wood was observed. The total biomass of Eucalyptus was 56.64 Mg ha-1, being 83.70% wood, 6.52% in branches, 6.37% in bark and 3.40% in leaves.&#x0D; Conclusion: The volumetric models developed by Schumacher and Hall as well as Ogaya were found to be applicable for estimating the volume of wood in CLF systems, where both showed a determination coefficient of 0.866.

Quantifying driving factors of vegetation carbon stocks of Moso bamboo forests using machine learning algorithm combined with structural equation model

Moso bamboo (Phyllostachys pubescens) is widely distributed in subtropical China and plays an important role in carbon cycling in terrestrial ecosystems. Knowledge of the main driving factors that affect aboveground carbon stocks in Moso bamboo forests is needed to increase carbon sequestration potential. We used a large-scale database from national forest continuous inventory from 2004 to 2014 in Zhejiang, China, and combined Random Forest analysis (RF) with structural equation modeling (SEM) to quantify the contribution of main driving factors on vegetation carbon stocks in Moso bamboo forests, and to evaluate the direct and indirect total effects of the main driving factors on aboveground carbon stocks, as well as to investigate changes in the standardized total effects from 2004 to 2014. The RF model explained 84.9% of the variation in 2004, 78.8% in 2009, and 82.2% in 2014. The SEM that included the average age, average diameter at breast height (DBH), culms density, mean annual temperature (MAT), and mean annual precipitation (MAP) explained 92.5% of the variation in 2004, 88.2% in 2009, and 88.6% in 2014. The results showed that average age, average DBH, culms density, MAT, and MAP were the most crucial driving factors of vegetation carbon stocks in Moso bamboo forests. The values of standardized total effects of the main driving factors showed that the average age, average DBH, and culms density had positive effects on vegetation carbons stocks, whereas MAT and MAP had negative effects. Furthermore, the positive effects of average age on the increase of vegetation carbon stocks increased significantly, the negative effects of MAT increased with the increasing MAT, but the negative effects of MAP decreased with the increasing MAP. Overall, our study provided new insights into the sensitivity and potential response of carbon sequestration in Moso bamboo forests to structural development and climate change in Zhejiang Province.

Structural development and carbon dynamics of Moso bamboo forests in Zhejiang Province, China

Abstract Moso bamboo (Phyllostachys pubescens) is widely distributed in subtropical China and plays an important role in terrestrial carbon cycling. However, the capacity of Moso bamboo forests to sequester carbon and their long-term structural development in large regions remain poorly quantified. We used the national forest continuous inventory data to measure and quantify the carbon stock and structure change from 2004 to 2014. The results of kernel density estimation showed that the culm density and average DBH (diameter at breast height) of Moso bamboo forests had a tendency to increase in Zhejiang Province. However, the culm structure of the Moso bamboo forests in Zhejiang Province was not optimal for high bamboo productivity. The aboveground culm carbon stock increased from 2004 to 2014, indicating that the Moso bamboo forests acted as a carbon sink. The average change in the aboveground carbon stock over the study period was 0.94 Mg C ha−1 yr−1, smaller than the corresponding value for different forest types in the same region and for the Moso bamboo forests managed by farmers in the lower mountain areas of central Taiwan (8.13 Mg C ha−1 yr−1), indicating that Moso bamboo forests have a large carbon sequestration potential. Furthermore, age classes 2–4 contributed positively to changes in the total aboveground culm carbon stock by 23.07%, 36.35%, and 50.17%, respectively. The change in the carbon stock was not correlated with any environmental factors, but the carbon stock increased with increasing culm density, average DBH (diameter at breast height), and culm age. Our results suggest that the Moso bamboo forests of Zhejiang Province have a large carbon sequestration potential if the structure and management strategies of the forests are optimized. This study improves our understanding of the carbon dynamics and structural development in Moso bamboo forests, which could help guide the future forest management strategies.

Influence of shaded systems on Xylosandrus compactus infestation in Robusta coffee along a rainfall gradient in Uganda

Abstract We investigated the relationship between characteristics of coffee shade systems and coffee pest infestation by the black coffee twig borer Xylosandrus compactus Eichhoff. The pest deprives Uganda of $40 millions annually, yet its control remains inadequate. The present study considered three rainfall zones in Central Uganda and 50 coffee plots that were randomly selected from each rainfall zone. Data were collected on X. compactus infestation and key shade indicators: canopy cover, tree‐species densities, diameter at breast height (DBH) and ratio of coffee to banana. Cluster analysis revealed two coffee shade systems: a matured shade tree (MST) system and a young poly‐culture (YPC) system. Xylosandrus compactus infestations were significantly less in the MST system than in the YPC system and significantly less in the low rainfall zone than in the high rainfall zone. An increase in the density of Carica papaya and Albizia chinensis significantly reduced and increased X. compactus infestation, respectively. A higher average DBH of individual trees and a higher density of trees that exude sap significantly lowered X. compactus infestation. Suppressing X. compactus infestation requires bigger trees, a high density of sap‐exuding trees and no Albizia chinensis. Further research should aim to investigate X. compactus flight activity and microclimate influencing X. compactus population dynamics.

Soil Base Saturation Combines with Beech Bark Disease to Influence Composition and Structure of Sugar Maple-Beech Forests in an Acid Rain-Impacted Region

Sugar maple, an abundant and highly valued tree species in eastern North America, has experienced decline from soil calcium (Ca) depletion by acidic deposition, while beech, which often coexists with sugar maple, has been afflicted with beech bark disease (BBD) over the same period. To investigate how variations in soil base saturation combine with effects of BBD in influencing stand composition and structure, measurements of soils, canopy, subcanopy, and seedlings were taken in 21 watersheds in the Adirondack region of NY (USA), where sugar maple and beech were the predominant canopy species and base saturation of the upper B horizon ranged from 4.4 to 67%. The base saturation value corresponding to the threshold for Al mobilization (16.8%) helped to define the species composition of canopy trees and seedlings. Canopy vigor and diameter at breast height (DBH) were positively correlated (P < 0.05) with base saturation for sugar maple, but unrelated for beech. However, beech occupied lower canopy positions than sugar maple, and as base saturation increased, the average canopy position of beech decreased relative to sugar maple (P < 0.10). In low-base saturation soils, soil-Ca depletion and BBD may have created opportunities for gap-exploiting species such as red maple and black cherry, whereas in high-base saturation soils, sugar maple dominated the canopy. Where soils were beginning to recover from acidic deposition effects, sugar maple DBH and basal area increased progressively from 2000 to 2015, whereas for beech, average DBH did not change and basal area did not increase after 2010.

The diameter increment of selected tree species in a secondary tropical forest in Sarawak, Malaysia

Abstract. Karyati, Ipor IB, Jusoh I, Wasli ME. 2017. The diameter increment of selected tree species in a secondary tropical forest in Sarawak, Malaysia. Biodiversitas 18: 304-311. The diameter at breast height (DBH) increments of dominant tree species in a secondary forest can determine forest growth in the area. This study was conducted to investigate the DBH increments of the nine dominant tree species in a secondary tropical forest. A total number of 180 trees representing nine species, seven genera, and six families were selected for the assessment of DBH increments during two years of study. Those nine species, namely: Acacia mangium Willd. (2.33 cm year-1), Endospermum diadenum (Miq.) Airy Shaw (1.05 cm year-1), Cratoxylum arborescens Blume. (0.96 cm year-1), Vernonia arborea Buch. Ham. (0.96 cm year-1), and Cratoxylum glaucum Korth. (0.80 cm year-1) had shown a high growth rate during the assessment, while the other four species such as Macaranga gigantea Mull. Arg., Macaranga triloba Mull. Arg., Euodia glabra (Bl.) Bl., and Vitex pubescens Vahl. had 0.53, 0.48, 0.37, and 0.30 cm year-1 in DBH increments, respectively. The average DBH increments for the entire selected species was 0.86 cm year-1 for periodic measurement and 0.75 cm year-1 for monthly measurement. This information is needed in order to understand the succession process in the secondary forests. It is important for the selection of the suitable species in a reforestation and a rehabilitation projects.&#x0D; Keywords: Diameter increment, fast growing species, secondary forest, selected speciesÂ

Examination of edge effects in a Cryptomeria fortunei plantation in Zhougong Mountain, western Sichuan

To investigate edge effects on community structure, species composition and diversity in an artificial forest, research was conducted on Zhougong Mountain, a forest park in western Sichuan, and a large fragmented plantation of Cryptomeria fortunei was selected as the sample plot. The average DBH (diameter at breast height), average height, average density, richness index (D) and Shannon-Wiener index (H) were used to evaluate edge effects. Based on a field survey, 5 transects (width = 10 m) were established from the edge to interior forest (gradient 1 to gradient 5), and 4 small plots (10 m × 10 m) were chosen in each transect using a random sampling method. Results showed that 111 species, belonging to 96 genera and 54 families were recorded in 20 small plots with a total area of 2,000 m. The following results were also found in this investigation: (1) The number of species decreased away from the edge to forest interior. (2) In terms of community structure, a decrease of average DBH was found in the tree layer with the increase of edge gradients. Average density followed the opposite pattern and no significant differences were found in average height. In the shrub layer, average density decreased with the increase of edge gradients and no significant differences were found in average height. Average density and height both decreased from the edge to interior forest in the herb layer. (3) Based on the analysis of species diversity, richness index (D) and Shannon-Wiener index (H) of the plantation, decreased values were generally found with an increase of edge gra•研究简报• 第 8 期 王德艺等: 川西周公山柳杉人工林群落的边缘效应 941 dients, and were much more obvious in the shrub and herb layer. Moreover, the number of common species and Sorensen’s similarity coefficient between edge gradients in the forest interior and edge 1 both showed a decreasing trend from the edge to interior forest. (4) Based on a comprehensive analysis, a clear change of community was found between edge 2 and edge 3, indicating that edge effects can reach 20 m into the fragmented patch of the Cryptomeria fortunei plantation.

Applicability of Satellite Remote Sensing in Accounting AboveGround Carbon in Miombo Woodlands

The crisis of climate change has drawn attention of ecologists all over the world to explore ways that could effectively enhance the sequestration of carbon in forests and woodlands. This necessitates forest inventory, along with knowledge of techniques that are quick and manageable. The present study was carried out in Miombo woodlands of western Tanzania namely, Kitwe and Mgaraganza. The aim of the present study was to investigate the effectiveness of remote sensing in estimating the stock of carbon in Miombo woodlands. Two types of data namely, ground-truthing and satellite imagery were used. Ground-truthing data were obtained by measuring the diameter at breast height (DBH) of all trees in 30 and 20 concentric plots in Kitwe and Mgaraganza forests, respectively. The average DBH of trees in each forest was fitted in biomass allometric models to estimate the ground-truthing vegetation biomass. On the other hand, Landsat images of the two forests were used to compute the Normalised Vegetation Index (NDVI). The computed NDVI were regressed with the ground-truthing vegetation biomass to get the remotely sensed vegetation biomass which was assumed to be 50% carbon. The coefficients of determination between the ground-truthing above-ground biomass and the NDVI values were statistically significant at P<0.05. The above-ground carbon stock obtained by ground-truthing in Mgaraganza and Kitwe forests was 3 and 2 times higher than that of satellite remotely sensed data respectively. The above-ground carbon stock obtained from satellite remote sensing gives some impression thus a basis for remote sensing in Miombo woodlands.

A Study of Variation of Growing Traits of Liriodendron and Its Excellent Provenance Selection

In this paper,Liriodendron provenance forest at the age of twenty-two in Qionglai National Forest Farm in Sichuan province was taken as the research object,the main growth traits such as tree height (H), diameter at breast height (DBH),volume (V),height under branch(HB) and crown width(CW) were determined in order to analyze the genetic variation and conduct the selection of its provenance. The results showed that there were statistically significant difference in H,DBH,and V among different provenances,while there were significant difference in HB,and CW. The average H,average DBH,average V, average CW and average HB of 9 provenances were 12.44 m,20.20 cm,0.2182 m3,3.18 m and 8.35 m respectively. The elevation level had a significant influence on the DBH growth of Liriodendron. The hereditabilities of tree height, DBH, volume of tree, CW and HB were 0.856, 0.847, 0.806, 0.576 and 0.547,which indicated that the growth traits were strongly controlled by genetic factors. Three superior provenances Liping Guizhou,Xuyong Sichuan and America A, were selected by synthetic evaluation. The selected provenances' genetic increments of DBH, H and stem volume were 19.56%, 6.60% and 35.36% respectively. Six superior individuals were selected out by comprehensive appraisal,whose average DBH,H and stem volume were 30.4 cm,15.17 m and 0.5230 m3 respectively, and exceeded the population means of 22.09%,14.47% and 66.63% respectively. This study provided the material conditions and theoretical basis for the cultivation and popularization of Liriodendron in Sichuan region.

弄岗喀斯特季节性雨林枯立木多度的空间分布及影响因子

Standing dead trees are an important part of the composition of forest structure. Therefore, studying the spatial distribution of standing dead trees abundance and its impact factors has provided much needed insights to understand the mechanism of tree death and the succession of community. According to a 15-hm2 study plot investigation in northern tropical karst seasonal rain forest, Nonggang, southern China, the standing dead trees with DBH(diameter at breast height) greater than 1 cm were classified. And the spatial distribution of standing dead trees abundance and its impact factors like spatial, topographic and communities' were analyzed using zero-inflated negative binomial models. The results showed that:(1) there were 2254 standing dead trees in the plot with an average DBH of 6.21 cm. And the maximum DBH was 61.86 cm. The DBH size-class structure of standing dead trees exhibited an inverse J-shaped pattern. Dead trees with smaller DBH distributed more densely in the high elevation areas, whereas those with larger DBH had a higher density in the valley bottoms.(2) Standing dead trees with smaller DBH displayed an clumped distribution, while those with larger DBHs had a random distribution. And the abundance of standing dead trees displayed different spatial autocorrelation at different spatial scales.(3) As DBH size-class increased, the correlation between abundance and elevation, abundance and slope gradually increased, while that of abundance and convex, abundance and spatial adjacent factors gradually decreased. The correlation between abundance and spatial adjacent factors increased as unit spatial scale increased, and the correlation between abundance and convex, elevation, slope and community type factors gradually decreased as unit spatial scale increased. There were different spatial distribution of standing dead trees abundance existed as the scales changed. And the spatial, topographic factors, different communities have significant impact on these spatial patterns of standing dead trees abundance and the diameter class structure. In turn, the spatial distributions of standing dead trees have significant influence on the light resources and the distribution of woody debris, and then impact the species composition of communities.

Tree species biomass and carbon stock measurement using ground based-LiDAR

This study scrutinises the use of terrestrial laser scanning (TLS) to measure diameter at breast height (DBH) and tree height at individual tree species level. LiDAR point cloud scans are collected from uniformly defined control points. The result of processed TLS data demonstrates the precise measurements of tree height and DBH by comparing it with field data (DBH, tree height, tree species and location). The average tree height and DBH obtained through TLS measurements were 9.44 m and 43.30 cm, respectively. A linear equation between TLS derived parameters and field measured values were established, which gave the coefficient of determination (r2) of 0.79 and 0.96 for tree height and DBH, respectively. Further, these parameters were used to calculate above ground biomass (AGB) for individual tree species by considering a non-destructive approach. The total AGB and carbon stock from 80 different trees are computed to be 49.601 and 22.320 tonnes, respectively.

An allometric model for estimating DBH of isolated and clustered Eucalyptus trees from measurements of crown projection area

Owing to its relevance to remotely-sensed imagery of landscapes, this paper investigates the ability to infer diameter at breast height (DBH) for five species of Australian native Eucalyptus from measurements of tree height and crown projection area. In this study regression models were developed for both single trees and clusters from 2 to 27 stems (maximum density 536 stems per ha) of Eucalyptus bridgesiana, Eucalyptus caliginosa, Eucalyptus blakelyi, Eucalyptus viminalis, and Eucalyptus melliodora. Crown projection area and tree height were strongly correlated for single trees, and the log-transformed crown projection area explained the most variance in DBH (R2=0.68, mean prediction error±16cm). Including tree height as a descriptor did not significantly alter the model performance and is a viable alternative to using crown projection area. The total crown projection area of tree clusters explained only 34% of the variance in the total (sum of) the DBH within the clusters. However average crown projection area per stem of entire tree clusters explained 67% of the variance in the average (per stem) DBH of the constituent trees with a mean prediction error±8cm. Both the single tree and tree cluster models were statistically similar and a combined model to predict average stem DBH yielded R2=0.71 with a mean prediction error (average DBH per stem) of±13cm within the range of 0.28–0.84m. A single model to infer DBH for both single trees and clusters comprising up to 27 stems offers a pathway for using remote sensing to infer DBH provided a means of determining the number of stems within cluster boundaries is included.

경기도 태화산 V 영급 잣나무(Pinus koraiensis) 조림지의 지상부 바이오매스 상대생장식 개발

Allometric equations for leaf, branch, stem and total above ground biomass of Pinus koraeinsis trees were developed with diameter at breast height(DBH) of trees, which were growing in a pine plantation with the stand density of 410 tree ha and the average DBH of 29.1±5.2 cm in Mt. Taewha, Gyeonggi. Damage by Acantholyda parki reduced leaf biomass compared to other studies, however, its contribution to total biomass was minimal among parts. Comprehensive analysis revealed that constant in allometric equation for total above ground biomass (logY=a + blogX) was affected by average DBH and stand density, however, constant b was not. At the stand level, biomass for leaf, brach, stem, total above ground biomass were 6.68 Mg ha, 18.82 Mg ha, 101.02 Mg ha, 126.53 Mg ha, respectively. We developed a Korean pine stand biomass regression, which explained about 98% of variation with DBH and stand density based on comprehensive analysis.

Floristic Survey in Kekanadura Forest Reserve in Matara District of Southern Province of Sri Lanka

Kekanadura Forest reserve, with an extent of 333 hectares is situated in Matara District of thesouthern region of Sri Lanka. This national Man and Biosphere forest reserve represents thelowland dipterocarp rain forest type. Being situated closer to the boundary of intermediatezone, it has unique edaphic conditions. Considering vegetation characteristics someresearchers argue that this forest should be categorized under intermediate zone-low countryforest. This area receives 1700 mm mean annual rain fall, and the mean temperature is 31°C.The main purpose of conducting this baseline survey was get correct idea on existing florawhich are threatened by the Southern Highway project, as its next stage up to Kataragama hasbeen designed to run across one section of the forest reserve and presence of the plants whichare subjected to high commercial exploitation like Gyrinops walla. Due to the reason ofcloser proximity to the University of Ruhuna, this type of baseline survey will be beneficialfor the future academic works too.The present analysis is based on data collected from 24 plots across 6 line transects. Heighand DBH and Height of all the plants above 5 cm DBH found within the plots were counted.Over all 182 plant species are recorded within this forest reserve. Most of them are commonto other rain forests but some of the rare species like Exacum trinervium are also recordedfrom marginal areas where anthropogenic pressure is high. This forest surrounds a waterreservoir and therefore it will be important to retain the forest cover as it is to prevent soilerosion and to minimize siltation of the tank. The forest area includes 62 ha of Pinusplantation which area is currently undergoing natural regeneration with native species.The Shannon index of diversity is 1.61 in the natural forest area, while it is 1.35 for the Pinusplantation. Evenness of 0.77 is attributed to plants within the natural forest and 0.76 for treesfound in the Pinus plantation area. The dominance of natural forest and Pinus plantations are0.22 and 0.23 respectively. Highest Important Value Index (IVI) is marked for Dipterocarpuszeylanicus, while the dominant family found in the canopy layer is Euphorbiaceae, whichrepresents 14 species of plants. Threatened species like Gyrinops walla and Artocarpusgomezianus were recorded lower number of individuals.The natural forest area recorded 1,962 plants per hectare for the plants above 5 cm DBH,which belongs to 92 genera and 43 families. According to the analysis of diameter at breastheight (DBH) and population density of the trees in general, it is recorded that all specieswith typically very large trees have few individuals. The average DBH is 11.6 cm. Smallersized species have a large numerical representation. Dichapetalum zeylanicum, Humboldtialaurifolia, Memecylon sp., and Dracaena thwaitesii are the dominant undergrowth plants. In natural forest area 9.35% of the plants were above 25 cm DBH while it was 19.2 for Pinusplantation. It was also revealed that 53% of the plants in Pinus plantation are found 10 cmdbh. That means the gradual replacement of Pinus plantation by native species, becausejuveniles of the Pinus plantation are not being found in below the sub canopy level.Shape of this land area tended to apply a more edge effect on the forest reserve, while it alsocaused increased anthropogenic pressure. This is especially true regarding the fauna.However, the hermitage and influence of the Buddhist monks have helped to mitigate suchharmful influences and has helped to protect the nature

不同植被恢复类型的土壤肥力质量评价

PDF HTML阅读 XML下载 导出引用 引用提醒 不同植被恢复类型的土壤肥力质量评价 DOI: 10.5846/stxb201306111672 作者: 作者单位: 华南农业大学林学院,华南农业大学林学院,华南农业大学林学院,华南农业大学林学院,华南农业大学林学院 作者简介: 通讯作者: 中图分类号: S714.8 基金项目: 广东省林业科技创新专项（2010KJCX012-02，2011KJCX031-02） Soil fertility quality assessment under different vegetation restoration patterns Author: Affiliation: College of Forestry, South China Agricultural University,College of Forestry, South China Agricultural University,College of Forestry, South China Agricultural University,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:科学确定森林土壤肥力指标并进行肥力质量的评价，对立地生产力和多目标森林经营的研究有着重要意义。以采伐（径级12 cm择伐）迹地上发育来的稀树灌丛、针叶林、针阔混交林和常绿阔叶林为研究对象，进行每木调查与群落分析，并比较各群落土壤因子间的差异，用典范对应分析（CCA）和因子分析对土壤肥力质量进行定量评价。结果表明，CCA可以有效地筛选土壤肥力质量指标，有助于质量指标的科学确定；土壤肥力质量综合评价分值为稀树灌丛（0.438） > 常绿阔叶林（0.414） > 针阔混交林（-0.170） > 针叶林（-0.331）；演替初期（19 a）的植被恢复并未使土壤结构发生明显变化，土壤肥力质量是下降的；无人为干扰的3种群落类型，针叶林表现为更高的生物量积累，而天然更新的常绿阔叶林则更有利于生物多样性的增加与土壤养分的保蓄。 Abstract:Soil fertility quality assessment based on scientifically determined indicators has significant implications for the study of stand productivity and multi-objective forest management. We carried out plant census and community analysis, and compared soil physicochemical properties among forest communities in Kanghe Nature Reserve. The four community types, i.e., scrub, evergreen broadleaved forest, coniferous-broadleaved mixed forest, and coniferous forest, represented different vegetation restoration patterns originating from a selective-logging (at 12 cm diameter) event on the subtropical evergreen broadleaved forest. The main soil factors influencing tree composition and distribution were screened by Canonical Correspondence Analysis (CCA), which were subsequently used to build the minimum data set (MDS). Soil fertility quality was quantitatively assessed with Factor Analysis on MDS.The results showed that distribution of tree species was unevened. With the lowest species richness, the coniferous forest was exclusively dominated by Cunninghamia lanceolata, whereas in the most species rich evergreen broadleaved forest, codominant tree species existed. Average tree DBH (diameter at breast height) decreased successively among coniferous forest, coniferous-broadleaved mixed forest and evergreen broadleaved forest.Soils were highly acidic (pH < 5.0) and the content of AvK, ExMg, AvMn, AvZn and AvFe had no significant difference(P > 0.05)across the four forest communities. A lower canopy density due to less canopy trees resulted in the lower soil moisture content in the scrub community, which had a higher mineral element content than other vegetation patterns as a whole. Distribution of trees was closely related to soil environmental factors, but the results of CCA indicated that there was no significant correlation (Monte Carlo Test,P > 0.05) between composition and distribution of tree species and the seven soil factors, i.e., AN, ExCa, AvK, TP, ST, AP and NCP, which should be excluded when building the MDS. Therefore, the findings revealed that CCA was an effective tool for screening soil fertility quality indicators and establishing MDS by demonstrating the effect of soil fertility on plant patterns.Factor analysis was applied on MDS to assess the fertility quality and the cumulative variance explained by five principal components was 84.67%, indicating this evaluation method was reliable. The integrated soil fertility quality assessment scores for scrub, evergreen broadleaved forest, coniferous-broadleaved mixed forest, and coniferous forest were, in a descending order, 0.438, 0.414, -0.170, and -0.331, respectively. Vegetation restoration did not obviously change soil structural parameters, such as soil texture, capillary porosity, non-capillary porosity, and bulk porosity, however, soil fertility quality declined in the early succession stage (19 a). In the three community types without human disturbance, coniferous forest had the highest biomass accumulation, whereas evergreen broadleaved forest from natural regeneration was more conducive to the increase of biodiversity and soil nutrient accumulation. Site-specific indicators, including soil physicochemical factors and biological factors, should be selected in future assessment of soil fertility quality. The appropriate quantitative ecological methods could make the determination of evaluation index more scientific. 参考文献 相似文献 引证文献

Productivity and cost of biomass harvesting for energy production in coppice natural stands of Quercus pyrenaica Willd. in central Spain

Biomass growing stocks, harvesting productivity and costs of energy production, were studied in thinnings of Quercus pyrenaica. Eleven forest sites were selected in coppices located in Castilla y León (Spain). Three systems were employed for harvesting: a mechanised whole tree harvesting (WTH) system, which included chipping at landing; a fully mechanised cut-to-length (CTL) harvesting system for firewood; and a semi-mechanised CTL system with manual felling and bunching. Three WTH trials had a hauling off 34.7–44.1 oven-dried tonnes (odt) ha−1. In contrast, only 11.6–30.0 odt ha−1 were obtained in the other eight CTL trials. Biomass weight equations for stems and whole trees were fitted. Worker operations were time-studied using software designed by the authors. The WTH system reached maximum productivity rates of 3.9 oven-dried tonnes per productive hour (odt h−1) for the felling and bunching operation and 6.9 odt h−1 for the forwarding operation. The mechanised CTL harvesting method achieved a productivity range of 1.3–0.5 odt h−1 for the harvesting operation. Furthermore, the average forwarding productivity was 7.3 odt h−1. Motor-manual felling and crosscutting in the CTL system accomplished a productivity range of 0.7–1.9 odt h−1. Manual bunching resulted in similar values. The lowest firewood unit cost for trees with 10 cm of diameter at breast height (DBH) was 62.0 € odt−1 using a semi-mechanised CTL system. Under similar conditions, this cost was 85.2 € odt−1 for the mechanised CTL system. Finally, the cost corresponding to chips at landing from WTH sites (average DBH = 10 cm) was 65.3 € odt−1.

Application of TRIPLEX model for predicting Cunninghamia lanceolata and Pinus massoniana forest stand production in Hunan Province, southern China

The process-based hybrid model is a promising tool for predicting forest stand production on regional scales. TRIPLEX1.6 was adapted and parameterized to simulate Cunninghamia lanceolata and Pinus massoniana forest stand production in Hunan Province, China, using data from permanent sample plots established by the National Forest Inventory of China (CNFI). Monthly maximum and minimum air temperature and precipitation (derived from interpolation of the data collected at 369 meteorological stations in Hunan between 2000 and 2009) were used to run the model. Model calibrations and simulations were performed through threshold parameters and initial statuses at a regional scale. The species- and site-specific sensitive parameters were adjusted for estimating tree growth rate of different stand age or diameter at breast height (DBH). The improved parameterize procedure actually did increase model practicability. The site and species data for model validation were achieved by applying half the 2009 permanent sample plot data. Estimated stand average tree height (H), DBH, and biomass were validated against the other half of the 2009 data. Simulated results were consistent with the observed data in Hunan Province. Coefficients of determination (r2) of predicted and observed data were 0.83 for H, 0.82 for DBH, 0.90 for aboveground biomass, and 0.94 for total biomass, indicating that TRIPLEX1.6 is capable in predicting forest growth and biomass dynamics of subtropical coniferous forests. Moreover, independent validations determined that TRIPLEX1.6 demonstrated competence in extrapolating outcomes on regional scales as well as withstanding rigorous testing in predicting C storage in subtropical forest ecosystems.