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固氮树种人工混交林的研究概况 总被引：1，自引：0，他引：1
<正> 近年来,国内外对人工营造混交林日益重视,造林面积不断增加,而有关以能结瘤固氮的豆科和非豆科树种作伴生,与主要造林树种混交的试验研究报告逐渐增多。现根据国内外有关的文献资料,对固氮树种人工混交林的研究作简单的概述,并提出一些初步的看法。一、固氮树种人工混交林生长效益研究由于固氮树种能形成根瘤,将大气中游离态的氮固定,增加土壤可利用的氮源,促进主 相似文献
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几种固氮树种凋落物分析研究 总被引：2，自引：0，他引：2
对福建沿海山地人工混交林中的伴生树种台湾相思、杨梅等固氮树种的凋落物数量及氮含量进行了初步研究,并与主要造林树种的凋落物氮含量进行比较分析。结果表明:造林七年林分中台湾相思和杨梅年凋落物量分别为每公顷1177和1288公斤,其氮含量分别为2.32%和1.66%,显著高于非固氮阔叶树种组和针叶树种组凋落物氮含量的平均值。 相似文献
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马尾松、固氮树种混交造林探讨 总被引：1，自引：0，他引：1
选用固氮树种与马尾松混交,对促进马尾松生长作用十分显著,并可不断增加林地土壤肥力,保持地力资源的永续利用。树种搭配模式主要有:马尾松×杨梅、胡枝子,马尾松×南岭黄檀、胡枝子,马尾松×江南桤木、胡枝子。 相似文献
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小坪林场几种固氮树种混交林初步研究 总被引：1，自引：0，他引：1
在福建同安小坪林场进行七年固氮树种混交林试验研究,初步结果表明:固氮树种杨梅、相思树均能促进湿地松、火力楠、福建柏和杉木的树高、胸径的生长,增加幅度分别为11.1～52.2%和6～7%,特别是显著地促进了在该地区不是十分适生的杉木和福建柏的生长;四个树种杨梅、相思树混交林下的土壤有机质和全氮含量分别提高了11.7～22.0%和6.3～57.3%,且杨梅提高混交林林地土壤有机质的作用普遍大于相思树。此外固氮树种混交林形成合理的林分结构,改善林分小环境,幼林阶段,火力楠×相思树,火力楠×杨梅,湿地松×相思树和湿地松×杨梅是较为理想的人工林群落。 相似文献
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我国结瘤固氮树种资源及利用现状 总被引：3，自引：0，他引：3
我国结瘤固氮树木资源十分丰富，现已发现的豆科结瘤固氮树木有１８３种，非豆科结大对木有４４种，目前，不同固氮树种在土壤氮素输入，荒山绿化，能源提供，发展经济和保持生态环境等方面起着十分重要的作用。 相似文献
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笔者于1989年10月参加了在联邦德国召开的“杨树种源与育种”和“速生树种与固氮树种”两个学术讨论会。“杨树种源与育种”会议的内容涉及各国杨树育种概况和育种策略、常规育种、生物技术育种、和生理遗传研究等方面。“速生树种与固氮树种”会议 相似文献
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为了解华南地区固氮树种与非固氮树种造林对土壤碳氮磷化学计量特征及易氧化有机碳(ROC)的影响,对广东省鹤山市造林13 a的固氮树种厚荚相思(Acacia crassicarpa)人工纯林和非固氮树种尾叶桉(Eucalyptus urophylla)人工纯林的土壤碳(C)、氮(N)、磷(P)与ROC含量进行测定,分析固氮与非固氮树种造林后土壤C、N、P和ROC的特征及相关关系。结果表明:固氮树种土壤ROC与总有机碳(TOC)含量均显著高于非固氮树种(P<0.05),且ROC/TOC值小于非固氮树种,土壤碳稳定性更强;固氮树种总氮(TN)含量和C∶N值均显著高于非固氮树种(P<0.05),C∶P、N∶P和C∶N∶P均高于非固氮树种,但无统计学上的差异;在两种林分下,TOC和TN都呈极显著正相关关系(P<0.01);在固氮树种中,TOC、TN与ROC/TOC呈显著负相关关系(P<0.05),土壤含水量(SWC)、C∶P、N∶P与TOC呈显著正相关(P<0.05)关系。在土壤含水量较高的华南地区,固氮树种造林提高了土壤TN、TOC含量和土壤化学计量比,有利于提高土... 相似文献
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我国结瘤固氮树木资源十分丰富，现已发现的豆科结瘤固氮树木有１８３种，非豆科结瘤固氮树木有４４种。目前，不少固氮树种在土壤氮素输入、荒山绿化、能源提供、发展经济和保持生态环境等方面起着十分重要的作用。 相似文献
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沙地杨树刺槐人工混交林的改良土壤功能及养分互补关系 总被引：12，自引：1，他引：11
杨树刺槐混交林是我国北方地区沿河及滨海沙地上成功的固氮树种和非固氮树种人工混交林。本文在简单介绍混交林生长情况的基础上,主要对林地土壤养分改良及其种间Ｎ、Ｐ养分互补关系进行了阐述。指出杨树刺槐混交林生产力提高主要是因为林地土壤养分（特别是Ｎ素养分）的极大改善及树种间Ｎ、Ｐ养分的互补。混交林土壤Ｎ素养分水平提高的根本原因是林地土壤微生物活性高,加快了含Ｎ较高枯落物分解速度,增强了土壤氨化及硝化强度。而杨树刺槐种间的Ｎ、Ｐ养分互补则主要表现在混交林中杨树可将吸收入体内的Ｐ素通过根系接触转移给相邻的刺槐,而刺槐则可将固定的Ｎ素通过根系接触转移给杨树,而且Ｎ、Ｐ转移的强度很大。这种奇妙的树种间养分互补机制对杨树刺槐混交林幼林期生产力提高是有重大意义的。 相似文献
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Gunnar Thelin Ulrika Rosengren Ingeborg Callesen Morten Ingerslev 《Forest Ecology and Management》2002,160(1-3):115-125
Atmospheric deposition of N and S appears to have caused nutrient imbalance in Norway spruce stands in southern Sweden. This calls for a change of forest management to procedures that promote nutrient balance. Studies have shown lower soil acidity in Norway spruce/deciduous mixed stands than in spruce monocultures, but the tree nutrient status in such mixtures has not been much investigated so far.
The nutrient status of Norway spruce foliage and top mineral soil chemistry in monocultures and in stands mixed with beech, birch, or oak was investigated through paired comparisons on 30 sites in southern Sweden (27 sites) and eastern Denmark (three sites). In total, 45 mixed stands and 34 pure stands were included in the study.
Spruce needles from mixed stands had higher concentrations and ratios to N of K, P, and Zn than needles from pure spruce stands. Among the mixed stands, the K status appeared to be positively correlated with the percentage of deciduous tree basal area. Soil samples from mixed stands had a higher Mg concentration, base saturation, and BC/Al ratio than soil samples from pure stands. The spruce needle nutrient status was comparable in pure stands on fertile sites and in mixed stands on poor sites. We did not detect any differences in spruce tree growth between pure and mixed stands.
This paper discusses possible reasons for a positive effect on the tree nutrient status in mixed-species stands and the possibility of using mixed-species stands as a forest management procedure to avoid nutrient imbalance. 相似文献
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The mixed plantation of poplar (Populus spp.) and black locust (Robinia pseudoacacia) is one of the typical mixed stands with nitrogen-fixing and non-nitrogen-fixing species. Interaction between the two species
in the mixed stand is harmonious and productivity is high, making this kind of mixed plantation a very successful pattern
on poor sandy sites in north China. In this study, the fine root decomposition of the two species was investigated in the
mixed plantation of 27-year-old Canadian poplar (P. canadansis) and 22-year-old black locust on sandy sites along the Chaobai River in Beijing. Mechanism of harmonious interaction between
the two species was observed in the view of the nutrient cycle of fine roots. Results showed that: (1) the fine root decomposition
of Canadian poplar and black locust trees was different. Concentrations of N, Ca and Mg gradually increased and those of P
and K gradually decreased in the fine roots of poplar during the period of decomposition. Concentrations of N, P and K gradually
decreased in the fine roots of black locust during decomposition. The speed of nutrient decomposition in mixed fine roots
of the two species fell between the speed of the two pure samples. (2) During decomposition, the annual return amount of N,
K and Mg in fine roots of black locust was highest, followed by the mixed fine roots of the two species, and then the fine
roots of poplar. (3) The increased return amount of N in mixed fine roots could improve the N nutrient condition of poplar
trees. The return amount of P in poplar fine roots was greater than that of black locust, which could improve the P nutrient
of black locust trees. The interaction of mutual supplements of N and P nutrient cycle of fine roots between these two species
formed.
Translated from Scientia Silvae Sinicae, 2004, 4(4) (in Chinese) 相似文献
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杨树刺槐混交林细根养分动态研究 总被引：19，自引：0，他引：19
对两树种细根在北京市潮白河沿河沙地加拿大杨 (2 7a生 )刺槐 (2 2a生 )混交林中的分解情况进行了研究 ,从细根养分循环角度探索了两树种混交协调生长的机理。结果表明 :(1)加拿大杨和刺槐林木细根的分解特点不同 ,杨树细根在分解前期的N、Ca、Mg元素浓度逐渐升高 ,P、K元素浓度则逐渐降低。刺槐细根分解过程中N、P、K元素浓度逐渐降低 ,杨树刺槐混交林细根混合分解中各元素含量变化介于两树种细根单独分解之间 ;(2 )细根的N、K、Mg年归还量以刺槐纯根最大 ,两树种混根次之 ,杨树纯根最小 ;(3)混交林中N素归还量的增加有利于改善杨树的N素状况 ,杨树细根的P素归还量大于刺槐细根 ,有利于改善刺槐的P素营养 ,混交林杨树与刺槐在细根N、P养分方面形成协调互补的关系 相似文献
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通过分析黄土高原主要薪炭树种叶片的氮素营养，表明在这１４种树木中固氮树种的氮素营养一般高于非固氮树种。经数理检验，两类树木的氮素营养差异达显著水平。在分析和检验的基础上，进一步探讨了固氮树种在黄土高原的应用问题。 相似文献
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The conversion of anthropogenic into more natural, self-regenerating forests is one of the major objectives of forestry throughout
Europe. In this study, we present investigations on permanent plots with different silvicultural treatment in NE German pine
stands. Management of old-growth pine stands on acidic and nutrient-poor sandy sites differs in fencing, thinning, and planting
of certain tree species. The investigations were carried out on the community, population, and individual level of the pine
forest ecosystems. Thus, vegetation changes, size and height of tree populations, and height increment of tree individuals
were observed over a time span of 6 years. Special attention was paid to short-lived tree species such as, e.g., Frangula alnus and Sorbus aucuparia, as well as to Fagus sylvatica as one of the most typical forest tree species of Central Europe. Vegetation changes are interpreted as a consequence of
natural regeneration of formerly degraded forest sites, involving an increase in nutrient availability. High browsing pressure
can be considered as a key factor for the inhibition of tree seedlings and growth of saplings. Some Sorbus aucuparia individuals, however, succeeded in growing out of the browsing height also in unfenced stands. Few found specimens of Fagus sylvatica proved that this species is able to establish spontaneously on these relatively dry, acidic sites under continental climate
influence. Such natural regeneration processes, also including spontaneous rejuvenation of trees, can be integrated into silviculture
as passive forest conversion management. An active management like thinning of stands, planting of trees, and fencing can
accelerate forest conversion with regard to height growth and species number of trees. 相似文献
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Vladimir Shanin Alexander Komarov Raisa Mäkipää 《European Journal of Forest Research》2014,133(2):273-286
The objective was to analyse how differences in the initial proportions of tree species and site fertility affect carbon sequestration in living biomass and soil. We used the individual-based simulation model EFIMOD, which is able to simulate spatially explicit competition between trees for light and nutrients. Simulations were carried out for three site types with distinct initial stocks of soil nutrients. For each site, the 100-years undisturbed dynamics of monocultures and mixtures of three tree species (Betula pendula Roth, Pinus sylvestris L. and Picea abies (L.) H. Karst.) was predicted. Changes in the proportions of competing tree species were dependent on the fertility of the site: on poor sites, pine was the most competent species, while on rich sites, spruce increased its proportion during stand succession. Net primary production (NPP) and soil respiration were the highest in stands of two coniferous species and in stands with a high initial proportion of pine. Mixed stands were more productive than monocultures; the highest overyielding was observed with mixtures of two coniferous species. Simulated NPP and carbon stocks in all pools increased from poor to rich sites. The highest carbon stocks in standing biomass were observed for mixtures of conifer species and three-species mixtures; the greatest accumulation of forest floor occurred in stands with high proportions of pine. 相似文献
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The effects of species mixture on the growth and yield of mid-rotation mixed stands of Scots pine and silver birch 总被引：1，自引：0，他引：1
The effect of tree species mixture on stand volume yield and on tree-species-specific diameter and height growth rates were analysed in managed mixed stands of Scots pine (Pinus sylvestris L.) and silver birch (Betula pendula Ehrn.).Data were obtained from 14 repeatedly measured stands located in Southern Finland on mineral soil sites with varying admixture of Scots pine and silver birch. Statistical analysis was carried out for studying the effect of species mixture on the development of stand characteristics. For the analysis, the plots were categorised into three groups (plot types) according to the species dominance. In order to analyse species-specific growth rates, individual-tree mixed linear growth models for tree diameter and height growth were developed for both tree species.The results clearly show that the yield of the managed mid-rotation, mixed stands was greater for stands dominated by Scots pine than for stands dominated by birch, and the stand volume increment decreased with an increasing proportion of silver birch. Analysis of diameter and height growth by tree species revealed that the main reason for this pattern is the negative impact of birch competition on the growth of pine trees. The increase in diameter of pine was clearly hampered if the proportion of birch was high. An abundance of birch also slightly decreased the growth in height of Scots pine, although the effect was less than on diameter growth. Species mixture did not affect the diameter growth of birch but did have a significant effect on height development. Height growth of birch was considerably greater in pine-dominated stands than in birch-dominated stands. In pine-dominated mixed stands, the height growth of birch was quite close to that of dominant pine trees, and birches can endure in competition with pines for light.The results apply for even-aged and single-storey managed stands, where stocking density and structure are controlled with pre-commercial and commercial thinnings. The results are not applicable to unmanaged mixed stands undergoing self-thinning. This study provides new information on mixed stands from a silvicultural perspective, which can be applied in decisions involving the management of mixed stands. 相似文献
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Many boreal tree stands are neither clearly even-aged nor clearly uneven-aged. The stands may undergo a series of stages, during which an even-aged stand is transformed into two-storied mixed stand, and finally to multistoried or uneven-aged stand structure. The species composition often changes during the succession of stand stages. This study developed models for stand dynamics that can be used in different stand structures and species compositions. The model set consists of species-specific individual-tree diameter increment and survival models, and models for ingrowth. Separate models were developed for Scots pine, Norway spruce, and hardwood species. The models were used in a growth simulator, to give illustrative examples on species influences and stand dynamics. Methods to simulate residual variation around diameter increment and ingrowth models are also presented. The results suggest that mixed stands are more productive than one-species stands. Spruce in particular benefits from an admixture of other species. Mixed species improve diameter increment, decrease mortality, and increase ingrowth. Pine is a more beneficial admixture than birch. Simulations showed that uneven-aged management of spruce forests is sustainable and productive, and even-aged conifer stands growing on medium sites can be converted into uneven-aged mixed stands by a series of strong high thinnings. 相似文献
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Cacao agroforestry systems (CAFS) can provide supporting services such as optimum light conditions for cacao growth, water and nutrient cycling and regulating services such as pest and disease control and climate regulation. This review considers recent literature on the manifestation of these services in CAFS around the world to provide an overview of scientific knowledge. Crown structures of associated trees can facilitate optimum light conditions for cacao growth, and provide water through vertical root segregation. Leaf litter fall and roots from associated species contribute to nutrient cycling. Both nitrogen-fixing and non-nitrogen-fixing species can provide nutrients to the cacao plant, though competition from certain species may limit phosphorus and potassium uptake. Pest and disease regulating services can arise through careful shade management to create a microclimate which reduces susceptibility of cacao to fungal diseases and sun-loving pests. All CAFS store carbon to varying degrees; those resembling original forest much more than simple two-species systems from which shade trees are removed after maturity of the cacao stand. CAFS also promotes biodiversity conservation depending on structure, management, and landscape arrangement, though not to the extent of natural forests. Research opportunities to increase provision of these services include optimal spatial arrangement for nutrient cycling and functional diversity as well as landscape connectivity for biodiversity conservation. Trade-offs between carbon storage, biodiversity, cacao yield and socio-economic resilience are presented, indicating that optimization of ecosystem services in CAFS requires consideration of interactions between all services, including socio-cultural and economic ones. 相似文献