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观光木人工林生物量及生产力研究 总被引：1，自引：0，他引：1
对广西南宁良凤江国家森林公园27年生的观光木生物量和生产力进行测定研究,分析观光木人工林不同径阶生物量的分配规律和林分生物量、生产力,并根据林木各器官之间的相关关系,建立D2H与各器官生物量的估测模型。结果表明,观光木生物量随着径阶的增大而增大,不同径阶间差异显著;通过不同径阶D2H拟合的生物量估算模型,拟合精度高,可用于实际生产对该林分生物量的估算;观光木林分生物量为102.57 t/hm2,其中乔木层占了87.07%,林下灌木层、草本层及腐殖质层生物量分别为8.61 t/hm2、1.83 t/hm2、2.82 t/hm2。观光木人工林林分生产力为7.4 t/(hm2.a),具有较高的净生产力。 相似文献
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对云南玉溪磨盘山华山松人工林（16年中龄林、26年近成熟林、43年成熟林）生物量及N、 P、 K、 Ca和Mg等5种营养元素的分配格局和积累规律进行了研究。结果显示,3种林龄华山松人工林的生物量分别为181.515 t/hm2、284.679 t/hm2、295.311 t/hm2,乔木层生物量分别占林分的91.594％、94.760％、93.838％,乔木层的净生产力分别为10.391 t/（ hm2· a）、10.375 t/（ hm2· a）和6.444 t/（ hm2· a）;3种林龄群落各层生物量均为乔木层＞枯落物层＞灌木层＞草本层;乔木各营养器官营养元素含量大小是树叶＞树枝＞树根＞树皮（或树皮＞树根）＞树干;3种林龄华山松各器官营养元素含量均以N含量最高,其他元素含量依次为K＞Mg＞Ca＞P,其中树叶中的N含量最高,达到16.733 g/kg～21.368 g/kg;3种林龄群落营养物质总积累量分别为1497.993 kg/hm2、2257.161 kg/hm2和2810.246 kg/hm2,乔木层营养物质年积累量分别为77.532 kg/（ hm2· a ）、76.679 kg/（ hm2· a）、58.759 kg/（ hm2· a）。 相似文献
4.
以华北落叶松人工林为研究对象,选择18a、22a、38a等3个不同林龄的林分,每个林龄林分设置15块样地。通过样地调查,对华北落叶松人工林的林分生物量、林下植被层生物量、林分净生产力进行研究,以揭示其生物生产力。结果表明：华北落叶松人工林林分生物量随着林龄的增加而增加,18a、22a、38a的林分生物量分别为94．58t／hm2、101．19t／hm2、216．25t／hm2。各器官的生物量分配,以干材所占的比例最大,达到51．36％以上;华北落叶松人工林林下植被层中凋落物层与灌木、草本层的生物量也随着林龄的增加而不断积累;华北落叶松森林净生产力表现为乔木层的净第一生产力、不同林龄阶段的华北落叶松人工林植被净生产力均较高,达到4．60t／（hm2·a）以上,其中干材的净生产力积累最快,为2．36～3．20t／（hm2·a）。 相似文献
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以广西天峨县林朵林场12年生西南桦人工林为研究对象,研究其生长过程和生物生产力特征。结果表明:西南桦在桂西北具有较强的生长适应性,12年生平均胸径(去皮)、平均树高和平均蓄积量分别达到15.6 cm,16.8 m,170.10 m3/hm2;西南桦树高和胸径生长均以前5 a最快,随后随林龄的增长而下降;材积生长在8年生时达到峰值,之后开始下降但仍然保持较高的年生长量。12年生西南桦人工林林分生物量为130.86 t/hm2,其中乔木层、灌木层、草本层和凋落物层生物量依次为122.38,2.35,1.87和4.26 t/hm2,分别占93.52%,1.80%,1.43%和3.26%。林分乔木层年净生产力为10.20 t/(hm2·a),不同器官净生产力大小次序为树干、树叶、树枝、树根、树皮。 相似文献
6.
4年生及13年生西南桦人工林生物量的分布特征 总被引：4，自引：0，他引：4
通过对西双版纳普文林场4年生、13年生西南桦人工林生物量分布特点进行了研究。结果表明:西南桦人工林生物量4年生为19.54 t/hm2,13年生为84.29 t/hm2;西南桦年平均净生产力4年生为8.76 t/hm2.a,13年生为26.52 t/hm2.a。两个龄级林分生态系统的生物量分配格局为乔木层>草本层>灌木层>枯枝落叶层。其中乔木层生物量4年生为7.55 t/hm2,13年生为56.22 t/hm2;净生产力4年生为2.67 t/hm2.a,13年生为5.45 t/hm2.a;其生物量分配格局都为树干>根>枝>叶。同时,建立了预测两种龄级西南桦人工林及其器官生物量的回归模型,以供生产中推广运用。 相似文献
7.
长白落叶松人工林生物量的结构与分布 总被引：1，自引：0，他引：1
采用径级标准木和样方收获法,对24a生长白落叶松人工林的生物量和生产力进行了研究。结果表明:24a生长白落叶松人工林分生物量为120.55t/hm2,年平均净生产力为8.47 t/(hm2.a),生态系统的生物量分配格局为乔木层>枯枝落叶层>下木层>草本层,其中乔木层生物量为102.17t/hm2,净生产力为8.09t/(hm2.a),其生物量分配格局为树干>树根>树皮>树枝>树叶;在林分产量结构方面,8 m以下树干生物量占其总量的81.80%,树枝和树叶的生物量主要分布在10～14 m,分别占树枝和树叶总生物量的71.11%和73.05%,地下根系生物量分配格局为粗根(直径大于5 cm)>根头>中根(0.5～5 cm)>细根(<0.5cm),粗根生物量占根总生物量的53.98%。 相似文献
8.
通过对岷江上游干旱河谷区人工林单株和林分生物量的测定,研究了人工林地上生物量、根系生物量积累及其分配,对不同树种生产力进行了比较研究.结果表明:(1)岷江柏(Cupressus chengiana)Ⅰ、岷江柏Ⅱ、刺槐(Robinia pseudoacacia)、榆树(Ulmus pumila)和辐射松(Pinus radiata)的单株生物量分别为240.3707 g、82.2402 g、37.7339 g、34.2295 g、26.6739 g,林分总生物量分别为769.186 kg·hm-2、272.215 ks·hm-2、72.297 kg·hm-2、68.87 kg·hm-3 和56.016 kg·hm-2.(2)岷江柏Ⅰ、岷江柏Ⅱ、榆树、刺槐和辐射松的根桩、粗根、中根和小根(Φ>2 mm)的根系生物量总和占单株根系生物量的百分比分别为82.87%、58.99%、76.8%、83.0%和35.79%,不同树种细根生物量(Φ<2 mm)占根系生物量的百分比大小顺序为辐射松(64.2%)>岷江柏Ⅱ(41.0%)>榆树(23.2%)>岷江柏Ⅰ(17.1%)>刺槐(17.0%).(3)林木地下部分与地上部分关系密切,回归分析表明林分根系生物量与地上生物量符合线性关系.(4)不同林分乔木层年平均净生产力大小顺序为岷江柏Ⅰ>岷江柏Ⅱ>刺槐>榆树>辐射松,岷江柏Ⅰ生产力最高,林分年平均净生产力达128.20 ke/hm-2·a-1,辐射松生产力水平最低,林分年平均净生产力只有14.00 kg·hm-2·a-1,仅为岷江柏Ⅰ的10.9%. 相似文献
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《西部林业科学》2015,(4)
对广西来宾市维都林场36年生顶果木人工林生态系统碳含量、碳密度及其分配格局进行了研究。结果表明,乔木层不同器官平均碳含量为501.7 g/kg,介于483.40~516.95 g/kg之间,表现为:树叶树干根兜粗根枯枝中根鲜枝细根树皮;生态系统碳密度为554.89 t·c/hm2,其中乔木层和土壤层为主要的碳库,分别为406.60 t·c/hm2、143.72 t·c/hm2;不同层次表现为乔木层(占总量73.28%)土壤层(25.90%)灌木层(0.55%)凋落物层(0.25%)草本层(0.02%)。顶果木年净固碳量为32.18 t·c/(hm2·a),净碳素累积量为11.29 t·c/(hm2·a),具有很高的固碳能力。 相似文献
10.
本文对海拔930rn的17年生海南五针松(Pinus fenzeliana Hand—Mazz.)人工林分生物量和生产力进行了测定。按平均标准木法和样方收获法分别调查了乔木层、下木层、草本层和枯枝落叶。据凋查效据,建立了估测乔木层单株林木各器官生物量的回归方程。结果表明:林分总生物量平均为161.152吨/公顷,净生产量为10530.69公斤/公顷·年;其中,乔木层生物量为149.35吨/公顷,净生产量为8785.35公斤/公顷·年;叶面积为每公顷199248.7339m~2叶面积指数为19.9149公顷/公顷。从林分的产量结构上反映出下木层结构不合理,应予间伐。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage. 相似文献
13.
Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and
also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the
amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter
bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K
was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed
significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week−1 for leaves and from 0.0225 to 0.0633 week−1 for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed
during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly
between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species
provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient
enrichment capacity and slower decomposition rates which would minimize leaching losses.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):118-130
The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions. 相似文献
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Astra Zaluma Lauma Bruna Darta Klavina Natalija Burnevica Kristine Kenigsvalde Andis Lazdins Talis Gaitnieks 《Forest Pathology》2019,49(6)
Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered. 相似文献
16.
《Scandinavian Journal of Forest Research》2012,27(1):53-61
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
17.
《Scandinavian Journal of Forest Research》2012,27(1):15-27
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions. 相似文献
18.
Steven Maranz Amadou Niang Antoine Kalinganire Djeneba Konaté Bocary Kaya 《Agroforestry Systems》2008,72(3):231-239
Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional
data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral
contents and B1 and B2 vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising
germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B1 88 mg 100 g−1, B2 187 mg 100 g−1, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal
diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties
to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations. 相似文献
19.
《Wood material science & engineering》2013,8(2):76-84
Abstract Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists. 相似文献
20.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。 相似文献