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1.
《中南林业科技大学学报(自然科学版)》2017,(6)
本研究比较了丘陵地区油茶单作、花生单作及油茶-花生间作三种种植模式下五种土壤酶(蔗糖酶、蛋白酶、脲酶、酸性磷酸酶、过氧化氢酶)活性的差异,并采用相关分析、通径分析对土壤酶活性和土壤养分的相关性进行了研究,旨在探讨油茶种植模式对土壤酶活性的影响,以期为油茶生产中培肥和改良土壤提供参考。结果表明,不同种植模式对土壤酶活性影响明显。与油茶单作相比,油茶-花生间作显著提高0~10 cm土层土壤蔗糖酶、蛋白酶、脲酶及过氧化氢酶的活性,以及10~20 cm土层蔗糖酶活性;与花生单作相比,油茶-花生间作显著提高了0~10 cm土层土壤蛋白酶活性。相关性分析表明土壤酶活性与土壤养分的相关性较高,特别是脲酶和酸性磷酸酶。通径分析结果表明,土壤速效磷和速效钾对蔗糖酶产生显著的直接影响,有机质和速效磷是影响蛋白酶的主导因子,土壤全氮是影响脲酶的重要因素,土壤全氮和速效磷是直接影响酸性磷酸酶的重要因子。综合看来,与油茶单作相比,油茶-花生间作模式可以改善土壤质量,提高土壤酶活性,对提高土壤肥力有着重要意义。 相似文献
2.
三峡水库岸坡系统不同用地类型对土壤酶活性和土壤化学性质的影响 总被引：3，自引：0，他引：3
以三峡水库岸坡系统常见的5种不同土地利用类型(林地、草地、退耕地、耕地、消落带)为对象,研究不同用地类型下土壤酶活性、土壤化学性质及其二者之间的关系。结果表明:林地土壤的过氧化氢酶、脲酶、碱性磷酸酶的活性在所有用地类型中最低,这与耕地土壤中的蔗糖酶、蛋白酶活性最低形成鲜明对照。与之相反,退耕地土壤中的脲酶、蛋白酶活性最高,而草地中的蔗糖酶、碱性磷酸酶活性居于最高。相关性分析表明:土壤过氧化氢酶、碱性磷酸酶活性与全氮、速效氮、全磷、有机质含量以及pH值分别呈现极显著的正相关,但碱性磷酸酶活性与速效磷含量呈现出极显著的负相关。蔗糖酶和脲酶活性则与全氮、速效氮、速效磷、pH值也呈显著的相关性。脲酶与有机质含量之间、蛋白酶与全氮、速效氮、pH值之间均分别呈显著相关性。林地土壤的全氮、速效氮、全磷、速效磷含量在几种用地类型中居于最低,岸坡林地能够有效减少可能进入三峡库区水体的N,P含量。消落带土壤中的速效氮、速效磷以及全磷含量在所有用地类型中最高,消落带的人为耕作可能是加剧水库水体N,P元素富营养化的重要来源之一。建议在三峡库区进一步增加林地,限制在消落带进行耕作等农事活动。 相似文献
3.
不同连茬代数杉木人工林生长及土壤性质比较研究 总被引：3，自引：0，他引：3
对２０年生的第１代与第２代的杉木林生长及土壤化学性质和酶活性进行研究。结果表明，第２代的林分平均胸径、平均树高、优势高及蓄积量比第１代显著的低；第２代的土壤有机质、水解Ｎ、速效Ｐ、速效Ｋ、交换性Ｍｇ比第１代明显下降；第２代土壤过氧化氢酶、蛋白酶、磷酸酶、蔗糖酶、多酚氧化酶与脲酶的活性显著地低于第１代。这表明杉木连载后土壤的化学性质和酶活性都明显劣变，进而导致第２代杉木生长明显下降。 相似文献
4.
复合农林模式中根际与非根际土壤的酶活性动态研究 总被引：1，自引：0，他引：1
土壤酶活性能够实质性的反映土地管理和土壤健康状况。为了更好的了解复合农林模式中土壤酶活性的变化规律和功效,本研究对花椒（Zanthoxylum bungenum）模式、桃树（Prunus persica var.nectariana）模式、桑树（Morus alba）模式和梨树（Pyrus pyrifolia）模式根际与非根际土壤酶活性与土壤养分进行了对比分析。结果表明：由于在林下广泛种植多年生黑麦草（Lolium perenne）,使得木本植株根际与非根际土壤酶活性没有显著的差异,但它们的活性都远远高于其对照地。除各模式多酚氧化酶活性的峰值均出现在9月份外,过氧化物酶、蔗糖酶、磷酸酶、脲酶的峰值多出现在7月和8月份。有机质与这5种土壤酶活性都有显著的正相关,而全N仅与磷酸酶和蔗糖酶有显著的正相关,pH值则与它们呈显著的负相关。植物组成可能对土壤酶活性和土壤化学性质有直接的影响。 相似文献
5.
矿质肥料对柳杉苗根区土壤生化活性的影响 总被引：4，自引：0，他引：4
对柳杉１年生苗施用矿质肥料,分析苗木根区与非根区土壤养分、土壤酶活性、土壤微生物数量。结果表明：施肥显著地增加了柳杉苗根区土壤的微生物数量,细菌增幅最大,其次是真菌,施肥对非根区土的微生物数量无明显影响;施肥对柳杉苗根区土壤酶活性影响较复杂,脲酶和蔗糖酶的活性不受施肥影响,磷钾和氮磷钾处理均能显著提高蛋白酶活性,施肥还能有效地降低柳杉苗根区土壤多酚氧化酶的活性。 相似文献
6.
杉木桤木混交林土壤酶与土壤肥力的研究 总被引：3，自引：0，他引：3
对杉木桤木混交林和格木纯林土壤酶与肥力因素的分析表明，混交林下土壤过氧化氢酶，脲酶，磷酸酶，蔗糖酶活性都高于用木纯林，脲酶，磷酸酶，蔗糖酶几乎与所有土壤肥力因素呈显著或极显著相关；杉木桤木混交林下土壤酶活性的提高，有利于土壤有机质的转化和土壤养分含量的增加。 相似文献
7.
土壤微生物总数及细菌、真菌数量、土壤酶活性（特别是蛋白酶、磷酸酶和蔗糖酶）及土壤养分状况（主要是有机质含量）从杉木幼龄林到中龄林随着林冠的郁闭，林下植被盖度急剧下降，呈明显下降趋势；土壤微生物总数，细菌总数，蛋白酶，磷酸酶，蔗糖酶以及土壤有机质从中龄林到成熟林随着林木密度及郁闭度下降，林下植被盖度逐步得到恢复，也呈明显的上升趋势。由于过氧化氢酶和多酚氧化酶活性的降低，有可能导致中龄林土壤中多酚类有毒物质的积累，这或许是杉木连栽产量下降或成活率低的原因之一。 相似文献
8.
小兴安岭谷地云冷杉林土壤酶活性的异质性 总被引：2，自引：0，他引：2
利用传统统计学与地统计学相结合的方法对小兴安岭谷地不同死亡程度云冷杉林表层土壤（0~20cm）酶活性空间异质性和格局进行研究。结果表明：①土壤脲酶变异函数曲线的理论模型符合线性模型,土壤转化酶、碱性磷酸酶和过氧化氢酶的理论模型符合指数模型或球状模型。②土壤酶活性各项指标的空间变异主要是由结构性因素引起,土壤碱性磷酸酶活性和过氧化氢酶活性指标的空间自相关程度均属较强以上（空间结构比均在75%以上）,土壤转化酶为中等（空间结构比均在25%以上）,土壤脲酶在较弱到中等之间变化。③云冷杉林表层土壤过氧化氢酶的自相关范围最大（0.58~3.08 m）,转化酶和碱性磷酸酶分别为1.41~3.98 m和0.91~4.29 m,而土壤脲酶自相关范围最小（15.426~16.673 m）。④土壤转化酶、碱性磷酸酶和过氧化氢酶活性的空间格局明显,土壤转化酶、碱性磷酸酶、过氧化氢酶和土壤脲酶的分数维分别为1.930~1.990,1.910~1.986,1.923~1.997和1.936~1.970。 相似文献
9.
高低产毛竹林地土壤酶活性比较分析 总被引：9，自引：0，他引：9
高产竹林地土壤过氧化氢酶、脲酶、蛋白酶和蔗糖酶的活性都高于低产竹林地;磷酸酶活性两种地类间无明显不同。低产竹林地各类酶活性与土壤有机质、全氮、水解氮及有效磷含量均有显著或极显著相关性;高产竹林地土壤有效磷含量与所有酶活性都无相关性,磷酸酶活性和土壤有机质、全氮、水解氮及有效磷含量相关性也不显著。 相似文献
10.
《林业科学研究》2021,(2)
[目的 ]研究不同森林类型中模拟N沉降对土壤酶活性的影响,旨在为N素对区域森林土壤酶活性及土壤活动相关研究提供理论依据。[方法 ]以滇中磨盘山典型森林云南松(Pinus yunnanensis Franch.)林、高山栎(Quercus semecarpifolia Smith)林、华山松(Pinus armandii Franch.)林和常绿阔叶(Evergreen broad-leaf)林为研究对象,于2018年1月—2018年12月设置:对照(CK,0 g N·m-2·a-1)、低N(LN,5 g N·m-2·a-1)、中N(MN,15 g N·m-2·a-1]和高N(HN,30 g N·m-2·a-1)4种N处理,测定不同施N水平4种林地0～5、5～10和10～20 cm土层蔗糖酶、淀粉酶、脲酶、天门冬酰胺酶、酸性磷酸酶、蛋白酶、过氧化氢酶、多酚氧化酶活性。[结果 ]表明:土壤深度对4种森林类型中8种土壤酶活性的影响均表现为10～20 cm土层土壤酶活性低于5～10 cm土层,降幅最高达76.8%,常绿阔叶林与云南松林土壤过氧化氢酶和高山栎林与云南松林土壤多酚氧化酶活性则在0～5 cm土层受到抑制,活性最低时仅为5～10 cm土层活性的15.4%;施N水平对土壤酶活性影响较为显著,LN显著抑制了高山栎林土壤蔗糖酶与淀粉酶活性;各N处理对脲酶、蛋白酶无显著影响;除常绿阔叶林外,LN处理显著提高了0～10 cm土层天门冬酰胺酶和酸性磷酸酶活性,各N处理抑制了华山松林土壤过氧化氢酶活性和各林分土壤多酚氧化酶活性,促进了高山栎林、云南松林土壤过氧化氢酶活性;森林类型对土壤蔗糖酶、淀粉酶、脲酶、天门冬酰胺酶、酸性磷酸酶、蛋白酶、过氧化氢酶和多酚氧化酶影响显著(P 0.01)。[结论 ]森林类型和土壤深度是影响N沉降下土壤蔗糖酶、淀粉酶、脲酶、天门冬酰胺酶、酸性磷酸酶、蛋白酶和过氧化氢酶活性变化差异的重要因素;土壤多酚氧化酶对施N水平反应敏感,对森林类型反应较不敏感;8种土壤酶中,天门冬酰胺酶对不同土壤深度、不同施N水平和不同森林类型三者交互作用的响应最为敏感。 相似文献
11.
《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
12.
《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
14.
《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
15.
《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
16.
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
17.
《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
18.
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
19.
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
20.
《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