滇西山地桉树林土壤物理性质研究

研究滇西不同利用类型下(桉树林、旱冬瓜林、示范林、云南松林)土壤的物理性质。结果表明,它们之间的关系是显著或极显著的,不同的利用类型和土层并对之影响显著;桉树林下土壤容重增加孔隙度下降,说明桉树林下土壤退化严重;示范林下土壤各项物理指标有所好转,具有一定的土壤恢复作用。     

The effect of tractor logging on forest soil compaction and growth ofShorea selanica seedlings in Indonesia

The hardness in soil was investigated in four forest areas in Indonesia after a crawler tractor passed over it several times. The hardness in soil, expressed by bulk density, was measured at various depth and various distances from the main track. Recovery of soil hardness was also examined. The bulk density increased markedly by the first and second pass of the tractor, but did not change after the fifth pass. The bulk density was highest just under the main and the log track, and decreased with an increase in distance from the track (0.5 to 1.5 m). The greatest increase in bulk density was observed at the depth of 0–5 cm. The soil hardness tended to show recovery within 9 years after logging, though not completely. Growth and root penetration of seedlingsShorea selanica decreased with the increase of soil hardness. We considered that the 2 tractor passes that caused bulk density of 1.3 g/cm³ is critical for the growth ofS. selanica’s seedling.     

桉树人工林土壤环境对植物种子发芽和生长的影响

桉树(Eucalyptus)已成为我国华南地区很重要的速生阔叶用材树种,在海南已成为仅次于天然林、橡胶林的第三大森林生态系统.但随着大面积营造桉树人工纯林,生产上出现一些负面的影响,其社会效益和生态效益问题日益得到重视,其旺盛的生长是否会造成地下水的过量消耗,大面积的种植桉树人工林从而造成部分林地降低了地下水位、造成土壤的退化和影响林下植物种子萌发、植物的生长,林下植被的减少,土壤的退化等(蒋有绪,1992;王震洪等,1998;陈秋波,2001;林义辉,2001;项东云,2002;黄志宏,2003).     

Quantifying root system quality of nursery seedlings and relationship to outplanting performance

With over 1.5 billion forest tree seedlings produced annually in the USA, seedling quality assessment is critical to ensure reforestation success. While height and root-collar diameter are the most common traits evaluated during seedling quality assessment, above-ground morphology is not always an accurate predictor of performance after outplanting. Root system morphology and physiological status may provide a more accurate indication of seedling potential. However, relatively few studies have attempted to quantitatively assess root system quality in relation to outplanting success. Large root volume, high root fibrosity, and an increased number of first-order lateral roots have shown some correlation to improved field performance. Physiological seedling quality assessment is commonly practiced through evaluation of root growth potential. Other tests, such as root electrolyte leakage, have also shown some potential as measures of seedling physiological quality. This review identifies current methods of assessing seedling root system quality and discusses potential shortcomings of these methods. An increased understanding of the suitability of current tests, coupled with the development of new tests and multiple parameter relationships, may foster the development of species and site-specific targets for seedling root system quality assessment. The production of seedlings with root systems that meet high morphological and physiological standards better enables seedlings to rapidly establish and thrive upon outplanting.     

吉林省林业苗圃土壤养分状况评价

本文通过不同区域点位土壤测试。对吉林省林业苗圃土壤养分状况、酸碱反应进行了评价。根据已掌握的土壤肥力状况。指出科学施肥对改良苗圃土壤。特别是对改良养分含量较低、碱性较强的西部苗圃的土壤具有重要意义。     

望天树人工林生长量及土壤理化性质

望天树是我国一级珍稀濒危保护植物,为了更有效地保护这一树种,在桂西南那坡县对29年生望天树人工林的生长量及土壤理化性质进行了研究。结果表明:林分平均胸径、平均树高和平均蓄积量分别为28.49cm、28.30m和440.5m3/hm2,净经济收入为39.65万元/hm2。林地0～100cm土层密度为0.819 8～1.174 3g/cm3,土壤总孔隙度为57.0%～66.3%,土壤通气度为16.8%～25.0%,土壤最大持水量、毛管持水量和最小持水量分别为46.7%～94.2%、34.1%～68.8%和20.8%～42.1%。0～40cm土层pH值为4.64～4.96,土壤有机质含量为29.58～70.70g/kg,土壤全N、全P和全K含量分别为1.15～2.71、1.38～1.56和13.27～15.31g/kg,速效N、P和K分别为157.68～327.42、0.32～1.21和9.93～23.12mg/kg。研究结果表明,29年生望天树人工林的生长量较高,林地土壤疏松、土壤通气性能良好、土壤肥力较高。因此,在类似该地区立地环境进行望天树的引种栽培具有较大的生物生产力。     

Frost tolerance of two-year-old Picea glauca seedlings grown under different irrigation regimes in a forest nursery

Abstract

This study examined the impact of increased irrigation efficiency on the hardening and frost tolerance of 2-year-old containerized white spruce seedlings in the context of groundwater protection, irrigation management and the maintenance of seedling quality in northern climates. The seedlings were grown under three different irrigation regimes (IR =30%, 40% and 55% v/v; cm³ H₂O/cm³ substrate) and were hardened under conditions of natural photoperiod and temperature. After being subjected to artificial frost tests on four sampling dates during autumn, the seedlings were compared for bud development and frost tolerance. IR had no influence on frost tolerance as determined by measurements of physiological (electrolyte leakage, root water loss) and morphological (shoot damage, root initiation) variables. At the end of the second growing season, there was no significant difference between IRs in seedling height, root collar diameter, shoot dry mass and root dry mass. The results indicate that the amount of water applied to large-dimension 2-year-old white spruce seedlings during the growing season can be significantly decreased without prematurely impeding their growth or hindering their acquisition of frost tolerance.     

Relationships between native tree species and soil properties in the indigenous forest fragments of the Eastern Arc Mountains of the Taita Hills,Kenya

The relationship between soil properties and spatial distribution of native woody species was studied in three Taita Hills forest fragments which, although degraded, are ranked among 34 biodiversity hotspots of the world due to their high biodiversity of both plant and animal species. This relationship was assessed by using Spearman correlation and principal component analyses (PCA). The results of these analyses should be useful in instituting forest restoration programs that are crucial for the forests. Both the soil and vegetation studied were sampled from 17 subplots in the natural forest fragments of Ngangao (120 ha), Chawia (86 ha) and Mbololo (185 ha). The soil variables measured were: pH, texture, soil nutrients of C, N, Ca, P, K, Mg and Na. In total 36 native tree species from 13 families were identified from the three forest fragments. Ordination results show that axis 1 accounted for 35% and axis 2 for 25% of the total variation in species composition, indicating that the structure of vegetation is related to two major environmental gradients. The correlation analyses of species and soil properties showed that Na and clay particles were the most important determinants of species distribution; pH and soil variables such as C, N, Ca and P also played minor roles. Unexpectedly, some species (e.g. Psychotria petitii) showed positive relationships with Na attributed to possible substitution for K. Relationships with P were both positive (e.g. Craibia zimmermannii) and negative (e.g. Albizia gummifera) with some species, attributable to pH levels. An ANOVA for soil variables showed that there were differences in the Ca content in Mbololo (due to the parent material) and P in Ngangao where a special relationship was observed between some of the species. The presence of gaps accounted for the distribution of seedlings but not for the saplings, whose distribution responded more to factors similar to those to which mature trees respond. Soil-species relationships that were established may be utilized along with soil analyses when choosing native species for restoration.     

退耕还林不同人工林类型对土壤养分的影响

对内蒙古敖汉旗2006年退耕还林的樟子松纯林、山杏纯林、山杏沙棘混交林和荒草地（对照）不同深度的土壤养分状况进行研究,结果表明：3种人工林的土壤有机质和碱解氮含量明显增加,山杏沙棘混交林中沙棘林带表层的速效磷含量明显增加,山杏纯林浅层的速效钾含量明显增加;3种人工林和荒草地的土壤养分随着土壤深度的增加而降低,表层土壤养分条件较好,说明土壤养分具有很强的表聚性;3种人工林与荒草地相比都不同程度地提高了土壤养分水平,樟子松纯林和山杏沙棘混交林中沙棘林带的土壤养分条件较好.     

Changes in soil chemistry and element uptake by Oak seedlings after application of soil amendment

ABSTRACT

The purpose of this study is to investigate the effect of cellulosic wastes and nanoscale zero-valent iron (nZVI) on the soil properties and the nutrient uptake by Quercus castaneifolia C.A.Mey seedlings. The seedlings were planted in pots (unpolluted soil) and cadmium (Cd) was added to the pots in three concentrations (10, 20, 30?mg.kg^?1). Cellulosic wastes were mixed with the soil (at the same time as the planting) in four levels (W: 0, 10, 20, 30?g.100g^?1 soil). The reduction method was used to prepare nZVI, then the nanoparticles were injected into the polluted pots in four levels (N: 0, 1, 2, and 3?mg.kg^?1). The lowest concentration of Cd in leaves, stems and roots and for all the contamination levels was observed in N3. All the cellulosic wastes and N3 significantly increased the soil pH at all the levels of contamination. An increasing trend of the soil carbon (C) content was observed by adding the cellulosic wastes. The highest pH and C content were observed in W3. The lowest bioavailable Cd contents for all the contamination levels was observed in N3. According to the results, nZVI and cellulosic wastes could help the plants establishing in heavy metal-polluted lands.     

锐齿栎林土壤呼吸对土壤水热变化的响应

按照5个土壤含水量(0.20、0.25、0.30、0.35、0.40 kg·kg-1)和5个温度(15、20、25、30、35 ℃)梯度设计试验,对取自北亚热带-暖温带过渡区锐齿栎(Quercus aliena var. acuteserrata)天然林中0～20 cm的原状土柱进行恒温培养和呼吸速率测定.结果表明:土壤温度、含水量及二者的交互作用都对土壤呼吸速率产生显著影响(P＜0.01); 土壤呼吸速率与土壤温度呈正相关,随土壤含水量增高的变化规律为单峰曲线,含水量为0.20～0.35 kg·kg-1 时土壤呼吸速率随含水量的增加而增加,0.35 kg·kg-1时土壤呼吸速率最高,0.35～0.40 kg·kg-1时随含水量的增加土壤呼吸速率下降,是对土壤呼吸产生抑制的土壤含水量临界点;锐齿栎林土壤呼吸Q10值的变化范围为1.36～3.10,平均为2.13,Q10随土壤温度的升高而下降,随含水量增加的变化趋势与土壤呼吸速率一致;土壤含水量0.35 kg·kg-1和土壤温度35 ℃结合下的土壤呼吸速率最高; 回归关系表明土壤呼吸速率与土壤温度呈显著的指数函数关系(P＜0.01),与土壤含水量呈二次函数关系(P＜0.10),土壤温度与含水量可以分别解释呼吸速率变化的73.26%与21.85%,共同解释能力为86.40%,土壤温度对呼吸速率的影响大于土壤含水量.     

两株外生菌根真菌对盐渍土壤中黑松幼苗生长的影响

为了研究外生菌根真菌对宿主植物黑松幼苗耐盐性的影响,采用盆栽实验,将成功侵染菌种土生空团菌(Cg)、紫晶蜡蘑(La)的黑松幼苗移栽于盐渍土壤中,培育3个月后,测定相关生理指标。结果表明:1)与非菌根化幼苗相比,接种菌根真菌Cg和La显著提高了针叶叶绿素a(由0.78 mg/g FW增加到1.27 mg/g FW和1.47 mg/g FW)和叶绿素b(由0.28 mg/g FW增加到0.40 mg/g FW和0.43 mg/g FW)的含量,增加了宿主体内脯氨酸含量(地上部:La> Cg> NM;地下部:La> Cg> NM),增强了K^+的吸收、转运,有效地维持(Cg菌种)或是降低(La菌种)了宿主地上部分Na^+/K^+的比值;显著(P <0.05)降低了宿主幼苗地下部的Na^+/K^+比值(由0.70降低到0.47和0.64)。2)外生菌根真菌有利于松树幼苗的生长,提高了其耐盐性,但因菌种而异(La> Cg)。深入研究不同菌种对不同宿主植物耐盐性的影响,将会成为后续菌根技术研究的一个重要方向,为沿海滩涂盐碱地的植被恢复提供理论依据及技术支持。     

攸县3种不同水土保持林土壤抗侵蚀性能

为了研究湖南省攸县境内的不同水土保持林对土壤抗侵蚀性能的影响,本文从林地土壤的物理性状、土壤抗蚀性能和土壤抗冲性能3个方面来进行对比研究。测定其林地0~20 cm层土壤的容重、孔隙度、水稳定指数、渗透系数、土壤团聚体占土样百分比和抗冲指数几个指标,进而分析不同林分类型之间的林地土壤抗侵蚀性能的差异。结果表明:从土壤的物理性状来看,楠+桤木+枫香混交林的容重和孔隙度均比其他两种林分要好;从土壤的抗蚀性能来看,3种不同林分的水稳性指数大小按照大小顺序为楠+桤木+枫香混交林枫香+栾树+桤木混交林杉木+柏木+马尾松混交林,楠+桤木+枫香混交林的渗透性能优于杉木+柏木+马尾松混交林和枫香+栾树+桤木混交林,且3种林分的水稳性指数与渗透系数均大于荒坡地;从土壤抗冲性能来看,土壤总团聚体占土样百分比和土壤抗冲指数按照楠+桤木+枫香混交林枫香+栾树+桤木混交林杉木+柏木+马尾松混交林的大小排列顺序,且指标均大于荒坡地。     

Relating sulfate adsorption to soil properties in Japanese forest soils

The relationship of sulfate adsorption capacity to the presence of aluminum, iron oxides, and organic carbon in four Japanese forest soils was investigated. Sulfate adsorption capacities were higher in subsoils than in surface soils, and their profiles were the inverse of those of organic carbon content. The black soil derived from volcanic ash had high sulfate adsorption capacity and showed no release of sulfate, while some of the surface horizons of the other soils desorbed sulfate. Oxalate extractable aluminum (Al₀) and iron (Fe₀) and ditionite-citrate-bicarbonate (DCB) extractable iron (Fe_d) were positively correlated with the sulfate adsorption capacity, and their correlation coefficients were almost identical (0.58–0.61). The lack of significant correlation between Al_d and the adsorption capacity suggests that DCB is unsuitable for extracting aluminum compounds which have the ability to adsorb sulfate. In contrast with oxides, organic carbon correlated with sulfate adsorption capacity negatively, and had a negative coefficient in a multiple regression equation, insignificantly. Furthermore, H₂O₂-treated samples containing decomposed organic matter adsorbed more sulfate than untreated samples. These results clearly indicated that organic matter hinders sulfate adsorption. A comparison of theβ value (standard regression coefficient) of organic carbon with that of Al₀ showed that the negative contribution of organic matter to sulfate adsorption capacity was slightly less than the positive contribution of oxides.     

Pisolithus tinctorius fails to improve plantation performance of inoculated conifers in southwestern Oregon

Bare-root stock of Douglas-fir, lodgepole pine, white fir, and grand fir, inoculated with Pisolithus tinctorius and handled by standard nursery, cold storage and planting practices performed no better than stock which was not intentionally inoculated but which had formed mycorrhizae with indigenous, nursery fungi on a variety of different outplanting sites in southwestern Oregon. Climate, planting sites and nursery practices in the Pacific Northwest differ drastically from those in the southeastern United States, where P. tinctorius has increased plantation survival and growth. Before P. tinctorius can be recommended for nursery inoculation in the Pacific Northwest, its reaction to each phase of the nursery and planting process needs to be carefully analyzed to determine where the problems lie.This article was written and prepared by US Government employees on official time, and is therefore in the public domain.     

竹酢液对杉木苗木生长效应和土壤肥力影响的研究

通过杉木幼苗的盆栽试验,采用喷施及土壤施入两种施用方法及9个不同浓度处理,分析施用竹酢液后对土壤化学性质以及杉木苗高和地径生长的影响。结果表明:施用竹酢液后,土壤pH无明显变化;H50和P300两种处理可以明显提高土壤全氮和速效磷含量,降低苗木生长过程中土壤速效钾、碱解氮和有机质等指标含量的衰减程度;促进土壤脲酶、多酚氧化酶和过氧化物酶的活性;对苗高和地径的生长有明显的促进作用。总体看来,适宜浓度的竹酢液对提高杉木人工林土壤肥力,促进杉木生长有利,其应用前景广泛。     

Physiological and phenological responses of oak seedlings to oak forest soil in the absence of trees

Established trees influence the growth and physiology of seedlings by altering above- and belowground conditions; however, tree influences on seedling physiology via belowground interactions are not well understood. We used soil transfers to an open field to examine the belowground influences of a Quercus ellipsoidalis E.J.Hill dominated forest on Q. ellipsoidalis seedling mycorrhizal infection, nutrient uptake, growth and photosynthesis over three years. After two years, seedlings planted with large quantities of forest soil (HF treatment) had greater leaf mass and foliar N concentrations than seedlings receiving smaller quantities of forest soil (LF) and control treatments. Mycorrhizal infection was greater in the HF treatment after one year compared with the LF and control treatments, with a positive correlation of foliar N and mycorrhizal infection in Year 2. There were marked effects of treatments on seedling spring phenology with HF seedlings breaking bud up to 17 days earlier than seedlings in the other treatments. The HF seedlings also had more rapid leaf expansion and larger leaves, and an increase in net photosynthetic rates. These results highlight complex linkages between above- and belowground physiology: forest soil had substantial effects on seedling physiology, including traits such as phenology that have previously been considered to be under aboveground control. Belowground influences of trees on conspecific seedlings may play a critical role in early seedling establishment.     

林业苗圃地连作和轮作对苗木生长及土壤肥力影响的研究

研究了林业圃地连作与轮作培育杉木、酸枣、厚朴等苗木的生长状况及土壤肥力的变化。结果表明:用水稻等作物与杉木轮作后,杉木苗生长状况改善,土壤有效养分和速效养分增加。     

污泥对苗圃生长的银合欢幼苗发芽和初期长势的影响

研究了不同类型的污泥(城市的、工业的和住宅污泥)对苗圃生长的银合欢幼苗田间萌发、生长和分枝的影响.播种前先将不同类型污泥的混合物与养分匮乏的自然林土壤混合.播种的3和6月后,记录幼苗大田发芽、分枝状况和其他物理生长参数(枝条或根长、活力指数、茎直径、叶片数、分枝或根鲜重和干重、总的生物量干重增长)等.与对照幼苗相比,混合污泥的土壤中生长的幼苗田间发芽、分枝状况及其他生长参数均发生了显著变化.与其它条件生长的幼苗相比,住宅污泥与土壤混合(1:1)条件生长的3月龄和6月龄幼苗分枝数和分枝鲜或干重均最高.就生长参数而言,住宅污泥与自然林土壤混合(1:1)生长的幼苗长势最好.研究表明:退化的土壤补偿以住宅污泥可促进银合欢的田间发芽、生长以及分枝的形成.图1表3参29.     

云台山森林土壤生产力的评价

研究了江苏省云台山地区赤松林分状况与土壤属性的关系。回归分析结果表明影响林木生长的主导因子是土层总厚度，其偏相关系数为０．９７，达到Ｐ０．０１（Ｐ０．０１＝０．７３５）的极显著水平，依据这一主导因子，将研究区内各亚类土壤划分为９个土型，按土壤生产力分级指标，对云台山的森林土壤生产力进行综合评价，可分为四级，云台山属土壤生产力中等的山体。