章古台沙地不同树种年龄和树种的生态系统叶片和土壤养分研究

对辽宁省章古台地区的几种主要针叶树种的针叶养分及其林分表层(0-15cm)土壤养分进行研究。结果表明,不同年龄樟子松(45、29和20年)(Pinussylvestrisvar.mongolica)林地表层土壤养分并无显著差别,而29年樟子松林分表层土壤全N、全P和N:P比显著高于相近年龄的赤松(P.densiflora)(29年)和油松林(P.tabulaeformis)(31年)。随着樟子松年龄的增加,叶片P含量逐渐减少,而叶片N和K含量则未表现出随年龄而变化的趋势;对于年龄相近的三个树种,叶片N和P含量表现为:樟子松>赤松>油松,而叶片K含量在三个树种中并无显著差别。表层土壤的全N和全P,有机质和全P以及叶片N和P含量之间表现出了显著的相关性,但是,林分表层土壤养分和树木针叶养分之间并无显著相关关系,这可能与当地对凋落物的过度收集,过度放牧以及土壤水分含量低有关。最后,根据国外研究结果引入N:P比阈值来分析研究区域的N,P养分状况,基于章古台地区这几种针叶树种针叶N:P比,我们认为研究区域的樟子松随着年龄的增加受N限制的可能性降低,29年的赤松林整体表现出不受N和P养分限制,而31年的油松林则表现为系统N和P都供应不足。图3表3参45。     

Relationships between Growth of Sitka Spruce (Picea sitchensis), Soil Factors and Mycorrhizal Activity on Basaltic Soils in Western Scotland

A survey was made of soil factors likely to be responsible forchecked growth of Sitka spruce on soils derived from basaltin western coastal areas of Scotland. Despite the high organicP contents of these soils, availability of P appears to be themain factor limiting growth; growth indices were significantlycorrelated with foliar P concentrations and inorganic P levelsof the soil. The low availability of soil P appears to be associatedwith high levels of oxalate-extractable Al (amorphous) in thesoils, a strong correlation existing between the latter andthe P sorption index of Bache and Williams. CaCl₂-extractableAl (‘available’) values were also high and althoughthey exhibited no significant correlation with growth therewas a negative correlation between growth and foliar Al concentrations. High mycorrhizal counts were associated with tree roots on siteswith better growth while beaded roots were mainly associatedwith poor growth. There is a suggestion that high CaCl₂-extractableAl in these soils may affect mycorrhizal development, as a strongcorrelation was found between the occurrence of beaded rootsand foliar Al concentration. Factor analysis confirmed that low availability of P in thesesoils may be ameliorated by mycorrhizal development and thata negative association exists between growth, the occurrenceof beaded roots and foliar Al concentration.     

White spruce foliar nutrient concentrations in relation to tree growth and soil nutrient amounts

Concentrations of foliar N, P, S, K, Ca, and Mg were studied in relation to stand age, tree growth, site index, and soil nutrient amounts for natural white spruce stands on a wide range of site conditions in the sub-boreal spruce zone of British Columbia, Canada. While Ca was sufficient in every sampled stand, relatively widespread deficiency in N was diagnosed. Deficiencies of other nutrients were diagnosed only on wet to very wet sites. Foliar N, P and K were negatively correlated with stand age and positively correlated with height and diameter growth. White spruce site index was positively correlated with foliar nutrients, and their relationships were quantified using a quadratic function. Foliar nutrients, except Ca, are positively correlated with soil nutrients measured in routine chemical analysis, and their relationships were quantified using Mitscherlich's function. It is recommended that the existing standards need to be modified should they be applied to nutrient diagnosis in natural white spruce stands. These standards appear too high for N and too low for P, K, and Ca.     

城市污泥应用于毛白杨林地施肥试验

为了妥善处置和利用城市污泥,使之变废为宝,采用城市污泥对毛白杨进行了不同立地施肥量、施肥时期试验.结果表明,污泥施肥改善了林地土壤的理化性状,对土壤具有修复作用.在不同施肥时期,不同立地条件下,施入一定量的城市污泥对毛白杨株高、胸径的生长均有促进作用,平原林地毛白杨净生长量优于丘陵地,污泥施入量以75 kg/株效果最佳.     

Nutrient supply at the local tree level in mixed forests of sessile oak and beech

In mixed-species forests, tree species composition can affect nutrient return through litter fall. This in turn is expected to have an effect on soil available nutrients, which could influence the nutrient status at the local tree level. Using ion-exchange resins, we estimated resin available soil nutrients at two depths beneath target trees of sessile oak and beech in the Belgian Ardennes. First we tested whether resin available nutrients were related to tree nutrition, using foliar nutrient concentrations as a proxy. In a second step, we tested whether local litter fall, through total nutrient return or litter species composition, affected resin available nutrients. In a final stage, we tested the impacts of local stand composition, as an integrated proxy of above- and belowground processes, and compared them to those of litter composition. With the exception of P for oak, nutrient supply was only poorly related to foliar nutrient concentrations for both target species. The effects of litter fall on nutrient supply were driven by litter species composition and not by total nutrient inputs. Litter composition and local stand composition effects were in close agreement. Our results show that nutrient supply to target trees in mixed-species stands is affected by local neighbourhoods, yet to a limited extent. Direct translation of resin available nutrients into foliar concentrations is probably hampered by complex capture patterns.     

Soil–water content and air-filled porosity affect height growth of Scots pine in afforested arable land in Finland

We examined the soil–water content (SWC) and air-filled porosity (AFP) of afforested arable land in situ and related them with tree growth, which was expressed as the total length of 5-year-height growth above 2.5 m stem height. A total of 34 randomly selected sites in western Finland afforested with Scots pine (Pinus sylvestris L.) were sampled and SWC was measured using time domain reflectometry (TDR). Increasing AFP up to 30% and correspondingly decreasing SWC significantly increased tree growth while concentrations of foliar nutrients and contents of soil nutrients had no effect. Increasing organic matter content (OMC) and decreasing bulk density (BD) were accompanied by increasing SWC and decreasing AFP in the 0–10 cm soil layer. SWC values above 70% indicated critical AFP below 10%. It was found that 44% of the studied sites had mean AFP lower than 10%. The results obtained indicate that the afforested Finnish arable land with high soil OMC is commonly characterized by high SWC and low soil aeration, which can limit tree growth.     

Relating visual crown conditions to nutritional status and site quality in monoclonal poplar plantations (Populus × euramericana)

The area covered by plantations of hybrid poplar in Europe is increasing greatly because of the high profitability of these trees. However, the productivity varies widely depending on nutritional status, and it is therefore essential to identify the limiting nutrients. The aims of this study were (a) to identify the main nutrients limiting the growth and vitality of monoclonal poplar (Populus × euramericana) plantations and (b) to develop a means of early detection of nutrition-related problems in growth, based on visual crown conditions (crown transparency, VCT, and visual crown discoloration, VCD). The study was carried out in one of the most suitable areas for this species in Southern Europe. Thirty-two Populus × euramericana (clone I-214) stands displaying different levels of decline were selected for study, and tree growth, nutritional status (soil properties and foliar nutrient concentrations) and crown conditions were assessed. The stands, which were growing in soils with high contents of coarse fragments, displayed low growth rates, poor crown conditions and deficiencies in Fe, B, N, P, K, and to a lesser extent, Zn and Cu. The deficiencies increased with the age of the stand, presumably because of the higher nutrient demand in older trees. Visual crown conditions were related to growth rates and nutritional status. Predictive models were developed to relate crown conditions to the nutritional status identified by analysis of soil properties and foliar concentrations of nutrients.     

Soil properties and tree growth on rehabilitated forest landings in the interior cedar hemlock biogeoclimatic zone: British Columbia

We studied operational landing rehabilitation programs in three forest districts of interior British Columbia (BC). Winged subsoiling and grass/legume seeding, followed by planting of lodgepole pine (Pinus contorta var. Latifolia) generally resulted in successful re-establishment of forest cover on landings. In the Boundary district, fifth year tree heights on landings were not significantly different from those in adjacent plantations, and fifth year growth increments were also similar despite evidence of delayed seedling establishment caused by cattle grazing damage. Trees on landings in the Kalum district were shorter than those in plantations, but fifth year increments were similar. Landings in the Kalum with >20% clay had lower stocking densities, tree heights, and probe depths compared to landings with <20% clay content. In the Kispiox district, average fifth year tree heights and fifth year increments were lower on landings than those on plantations. In the Kispiox district, landings with >20% clay content had shorter trees growing on them when compared to tree heights on landings with <20% clay. Landings in the Kispiox had the least probe depth of the three districts, and the greatest difference in height and increments between landings and plantations, supporting field reports of poor decompaction effectiveness there. In all districts, there was no forest floor present on landings 7 years after subsoiling, and cover of non-coniferous vegetation was lower than for plantations. Higher soil temperatures and lower soil moisture contents were recorded on landings relative to plantations in all districts during the growing season of 1998. Landing soils also had lower total C, N and mineralizable-N (min-N) than plantation soils in the Boundary and Kispiox, but such differences were not statistically significant in the Kalum. Reduced levels of total C, N and min-N on landings did not appear to have affected current foliar nutrient status of trees growing on these sites, as most nutrients appeared in concentrations considered adequate or only slightly deficient, except for foliar S on all sites. Average concentrations of N, P, K and S in foliage were either similar to or significantly higher for trees on landings relative to plantations, but these differences were attributed to dilution in plantation foliage rather than deficiency. Our results support the conclusion that operationally feasible techniques for soil rehabilitation can create conditions suitable for establishment of a new forest on sites that otherwise would be considered non-productive. Stocking levels and tree growth rates observed in our study are consistent with the conclusion that a commercial forest may be produced on some of the rehabilitated areas.     

相思树种在沿海沙质立地环境中的抗逆性研究

应用大叶相思、肯氏相思、毛娟相思、马占相思和厚荚相思等相思树种在东山县沿海沙地上营建防护林,并对其抗风、抗台风及抗连续干旱性能进行了测定。结果表明:厚荚相思抗风能力强,生长快,是较好的可在沿海沙地上适生的树种;相思树种抗台风能力较木麻黄弱,台风对相思树种的主要危害是断梢,但在以后的生长中能较快地得到恢复,对相思林分生长并不会产生大的影响;厚荚相思在沿海沙地上造林,不仅成活率高(95%以上),而且在遭受连续8个月的干旱后,旱死率为0,表现出很强的抗旱能力,而且在贫瘠的沙地土壤上生长表现良好,其生长量超过了木麻黄601无性系,是非常好的适合于沿海沙地条件的树种。     

Loblolly pine growth and soil nutrient stocks eight years after forest slash incorporation

Incorporation of forest slash during stand establishment is proposed as a means of increasing soil carbon and nutrient stocks. If effective, the increased soil carbon and nutrient status may result in increased aboveground tree growth. Eight years after study installation, the impact of forest slash incorporation into the soil on soil carbon and nutrient stocks, foliar nutrients and loblolly pine growth are examined on mineral and organic sites on the North Carolina Lower Coastal Plain. Treatments include leaving forest slash on the surface and flat planting (control); V-shear and bedding (conventional), mulch forest slash followed by bedding (strip mulch) and mulch forest slash and till into the soil followed by bedding (strip mulch till). After eight years, mulching and/or tillage did not have a significant impact (p > 0.05) on soil bulk density or soil chemical properties (pH, cation exchange capacity, soil nutrients). Additionally, neither tree foliar nutrients nor stand volume were significantly impacted. However, significant effects were observed for soil phosphorus contents and stand volume between the control plots and the other treatment plots. For example, the mean stand volumes on the mineral site were 24.49 ± 1.28, 38.16 ± 2.90, 44.59 ± 3.07 and 46.96 ± 2.74 m³ ha⁻¹ for the control, conventional, strip mulch and strip mulch till plots. These observations are more likely due to the effect of bedding rather than mulching or tillage of the forest slash. These results are consistent for the mineral and the organic sites. Considering the greater expense to install the mulch and tillage treatments, the lack of a treatment effect on soil carbon and nutrient stocks and tree growth does not justify these treatments on these sites.     

DRIS evaluation of teak (Tectona grandis L.f.) mineral nutrition and effects of nutrition and site quality on teak growth in West Africa

The objective of the investigation was to study the site variables controlling teak yield (Tectona grandis Linn.fil.) and to establish guidelines for the selection of high productivity sites in Benin, Côte d'Ivoire, Liberia, Nigeria and Togo. Depending on stand age, soil and region, between 70 and 90% of the variation in tree growth (site index, SI) could be explained by the supply of nitrogen, the root-available soil depth and precipitation. Diagnostic foliar analysis for a broad range of elements was carried out in all plantations with the exception of Nigeria. This showed that in 20% of the stands, various deficiency symptoms occur, and in an additional 40%, hidden demand of at least one nutrient is apparent. According to the Diagnosis and Recommendation Integrated System (DRIS), the most deficient nutrients besides N are Ca and P, while in 45% of all stands there is a relative Al excess. Recommendations for the evaluation and classification of site quality and the number of trees sampled for foliar analysis are given.     

Fertilization in a Fourth Rotation Eucalyptus grandis Plantation with Minimal Management

ABSTRACT

Successive rotation and wood harvest of fast growing trees, like Eucalyptus grandis, can deplete soil nutrient pools. In these intensively used soils, productivity can decrease, and fertilization can be necessary to recover soil fertility. The aim of this work is to evaluate if fertilization with N and P increases tree growth and foliar nutrients in an Eucalyptus grandis plantation growing over a soil used for three rotations of this species. In the same experiment, both fertilization on seedlings and coppiced trees were evaluated. One and two years after planting, any fertilization treatment increased tree growth, even though coppiced trees had higher total height and DBH than replanted trees. Coppiced trees had lower specific leaf area, as well as lower N and P leaf concentration. The lack of promotion in growth due to fertilization can be explained by the inputs of nutrients from the harvest residues of the previous rotation. As residues were never burned in this site, its decomposition released a high part of nutrients necessary to sustain growth during the first two years. We conclude that in sites where residues were left on site and were not burned, nutrient availability is enough and so fertilization at establishment is not necessary. It remains to be determined if fertilization is necessary at mid or end rotation, in order to balance nutrients export with harvest wood.     

Competition control in juvenile hybrid poplar plantations across a range of site productivities in central Saskatchewan,Canada

The response of hybrid poplar plantations established on former agricultural land in Saskatchewan to competition from weeds on a range of site productivities was studied. The short-term impact of competition control on the growth of juvenile trees and how tree responses to competition control differed across the productivity gradient was of particular interest, as was the determination of which resource was most highly competed for and was most important in determining tree growth. Eight sets of paired plots in juvenile hybrid poplar plantations were established in central Saskatchewan across a range of site productivities. In each pair, one plot had complete weed control (weed-free) while in the other plot weeds were allowed to grow. The best soil predictor of tree growth was soil texture, represented by a combination of the percentage silt and clay, with finer textures showing better growth. Competition control significantly increased tree growth on all sites with the benefit being greatest on the higher productivity sites. Soil water appeared to be highly competed for between trees and weeds and was a dominant resource controlling growth. For soil nutrients, nitrogen and phosphorous were highly competed for between trees and weeds. However, leaf phosphorous concentration of the weed-free plots had a strong positive relation to tree growth while nitrogen did not, indicating that when trees are free of competition they can access sufficient nitrogen from these soils.     

Concentrations of foliar and surface soil in nutrientsPinus spp. plantations in relation to species and stand age in Zhanggutai sandy land, northeast China

The concentrations of the foliar and surface soil nutrients and the variation with species and stand age were studied inPinus spp. plantations in Zhanggutai area, northeast China. The results showed that the total N, total P and C: N ratio of the soil inP. sylvestris var.mongolica stands were significantly higher in comparison with those inP. tabulaeformis andP. densiflora stands. ForP. sylvestris var.mongolica, the foliar P concentration appeared to decrease with age, and the foliar N and K concentrations did not show a consistent change with age. As for the different tree species of the similar age, the foliar N and P concentrations were significantly different (p<0.05), being withP. sylvestris var.mongolica>P. densiflora>P. tabulaeformis. The foliar N: P ratio ofP. densiflora significantly was higher thanP. sylvestris var.mongolica andP. tabulaeformis, while the foliar K was no obvious difference between the three tree species. There were significant correlation (p<0.05) between soil total N and P, soil organic matter and total P, foliar N and P, but it did not show significant correlations between soil and foliar nutrient concentrations, which might attribute to the excessive litter raking, overgrazing and low soil moisture in this area. Based on the foliar N: P ratio, we introduced a combination threshold index of N: P ratio with their absolute foliar nutrient concentrations to determine the possible limiting nutrient. According to the critical N: P ratio and their absolute foliar N, P concentrations, theP. sylvestris var.mongolica stands showed a decreased N limitation degree with age, theP. densiflora stands showed unlimited by N and P in the whole, and theP. tabulaeformis stands showed co-limited by N and P. No significant difference in soil nutrient concentrations of the surface soils was found between 45, 29, 20-yr-oldPinus sylvestris var.mongolica plantation stands. Foundation item: This research was supported by Key Knowledge Innovation Project (KZCX3-SW-418) of Chinese Academy of Sciences. Biography: CHEN Guang-sheng (1978-), male, master candidate in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China Responsible editor: Song Funan     

Effects of groundcover management on soil properties, tree physiology, foliar chemistry and growth in a newly established Fraser fir (Abies fraseri [Pursh] Poir) plantation in Michigan, United States of America

Incorporating cover crops into Christmas tree plantations may potentially improve soil fertility, tree growth and quality and be an alternative to commercial nitrogen (N) fertilizers. However, cover crops may compete with the trees for water and other nutrients than N. This study was carried out to assess whether soil fertility, tree survival and growth could be improved by incorporating leguminous and non-leguminous cover crops into the Fraser fir (Abies fraseri) production system. Dutch white clover (Trifolium pratense), alfalfa (Medicago sativa) and perennial ryegrass (Lolium perenne) were grown in a newly established Fraser fir plantation using two cover crop management practices; no banding (NB) by growing each cover crop throughout the entire plot and banding (B) by creating a 61 cm-wide bare zone centered on the tree rows. A conventionally-managed system (CONV) was used as a control. The cover crop aboveground biomass and N content were assessed. Soil available N (NO₃ ⁻ and NH₄ ⁺) and N mineralization were measured at 0–15, 15–30 and 30–45 cm soil depths. Tree survival, growth, photochemical efficiency of photosystem II (F_v/F_m), branch water potential (Ψ_w) and foliar nutrients were also evaluated. Biomass production was as high as 13.9, 10.2 and 5.9 Mg DM ha⁻¹ year⁻¹ for clover, alfalfa and ryegrass, respectively. Cover cropping increased soil available N by 1.5- and 2.2-fold relative the CONV in the top soil layer in 2007 and 2008, respectively. Tree seedling survival and growth in the B and CONV systems were similar. In contrast, NB treatments resulted in poor seedling survival and growth relative to the B and CONV plots. Plant Ψ_w and F_v/F_m decreased significantly for A. fraseri seedlings on the NB treatments relative to their counterparts on the B and CONV plots. However, cover cropping had marginal effects on foliar nutrients. Cover cropping with banding can be an efficient strategy for maintaining productivity in Fraser fir Christmas plantations.     

不同林龄樟子松叶片养分含量及其再吸收效率

树木叶片的养分再吸收效率能够反映树木对养分保存、利用以及对养分贫瘠环境的适应能力。以科尔沁沙地东南缘章古台地区樟子松人工林为研究对象,分析了11、20、29、45年生树木叶片的基本特征、养分含量及其再吸收效率。结果表明:叶片衰老后其质量和面积明显减少;叶片凋落前的平均养分含量没有表现出随樟子松年龄增加而出现有规律的变化;凋落叶片中的N、P、K、Mg含量表现出随年龄增加而增加的趋势,而Ca的趋势与之相反;11年生和20年生的樟子松叶片N、P、K的再吸收效率相似,都显著高于29年生和45年生樟子松(P<0.05),而樟子松叶片对Mg的再吸收效率表现出随年龄增大而显著降低,Ca随叶片的衰老而不断累积,再吸收效率表现为负值,20年生的樟子松叶片Ca再吸收效率最大,11年生和45年生最低。樟子松叶片的N、P、K、Mg养分再吸收效率随年龄增加而降低的趋势表明,随年龄增加樟子松对贫瘠养分生境的适应能力逐渐降低,反映了樟子松养分保存方面的衰退特征。     

沙地樟子松天然林和人工林中针叶养分含量比较

为了诊断沙地樟子松人工林的衰退原因,我们比较分析了沙地樟子松天然林和人工林中的叶片养分含量。结果表明,天然林中的樟子松叶片内氮、磷含量均比人工林中低,而钾含量比人工林高。樟子松人工林叶片中 N:P, P: K 和N: K在45年前随年龄增加而增加,从植物养分含量的角度来看,这一结果表明氮或磷可能不是沙地樟子松生长的绝对限制因子。然而,天然林和人工林叶片中的钾含量比以前报道过的松属植物中的含量都要低。天然林叶片中的N: P比值在正常的范围内,但人工林的则在该范围以外。这些结果表明天然林具有比人工林更好的养分平衡状况。如果只从樟子松的生长地来考虑,我们可以认为樟子松人工林的衰退现象可能是因其它的矿物元素或者氮和磷的有效性,而不是氮和磷的绝对含量不足造成的。养分的不平衡状况和人工林内针叶快速分解可能也是衰退的重要因素。图3表3参42。     

不同树种幼林生长差异及对土壤营养的影响

通过调查不同树种新造林树高生长量及其林地土壤有机质和速效氮、磷、钾含量,研究其生长及对土壤营养的影响.结果为：光皮桦、四川桤木、楸树、栾树、湿地松6年生树高分别为8.2、7.7、7.4、7.0、5.3 m;不同树种造林后对土壤营养物质含量的提高有明显差异,5个树种造林后效果排序的先后次序为光皮桦、四川桤木、栾木、楸树、湿地松;新造林均表现为造林当年土壤营养含量明显下降,第2年起逐年增加,第3～5年超过造林前水平.     

Effects of prescribed fire on canopy foliar chemistry and suitability for an insect herbivore

We assessed the effects of a prescribed fire on the phytochemical characteristics and vigor of overstory chestnut oak, scarlet oak, and red maple, and measured the impact of potential changes on herbivore fitness. We compared foliar carbohydrates, tannins, nutrients, and fiber concentrations in foliage from burned and non-burned forest canopies. There were significant differences in most foliar characteristics between tree species. Total non-structural carbohydrate concentrations in scarlet oak and red maple foliage, and calcium levels in red maple foliage, were significantly lower in burned plots, but other phytochemical characteristics were largely unaffected by burning. Tree growth also varied with species. Burning increased chestnut oak relative growth, decreased scarlet oak growth, and had no affect on red maple growth. Scarlet oak and red maple foliage from burned and non-burned forest canopies were assayed for gypsy moth performance. Caterpillars fed foliage from scarlet oak, the preferred host, grew larger and developed more rapidly than did those fed red maple foliage. There were no significant burn treatment differences in caterpillar development within either tree species, suggesting that managers using prescribed fire to promote oak regeneration need not worry about enhancing forest stand susceptibility to gypsy moth. However, the fire in this study was of low to moderate intensity; more intense fires may alter foliar palatability.     

厦门大学校园内石栗生长不良原因初步研究

通过对石栗 (Aleuritesmolucana)个体生长状况、生理指标、土壤养分和盐分含量及叶片元素含量的分析 ,初步认定厦门大学校园内的石栗生长不良的主要原因是盐害 ,而不是由于土壤养分缺乏。石栗是一种比较耐盐的园林绿化树种 ,在盐度不高于 3 5mg·g-1的土壤上能正常生长