无翼坡垒植物与土壤营养元素及化学计量学特征

为探讨无翼坡垒Hopea exalata土壤、根系和叶片营养元素含量及化学计量特征,以甘什岭省级自然保护区无翼坡垒群落为研究对象,根据物种胸径划分等级,选择幼树(2.5 cm≤DBH 7.5 cm)、小树(7.5 cm≤DBH 12.5 cm)和大树(17.5 cm≤DBH 22.5 cm)3个等级,比较其土壤-根-叶片元素含量及化学计量比的差异,探讨随林龄的变化及相互间的关系。结果表明:1)C、N、P含量表现为叶片根系土壤,土壤全N、全P和全Ca含量以大树最高;随着等级的增长,根系C和Mg含量呈上升趋势,N、P和K含量呈下降趋势;叶片C、P和K含量呈上升趋势,N、Ca和Mg含量呈小幅度下降趋势。2)不同等级土壤C/N、C/K比值以大树最高,叶片中C/N、C/K、Ca/K、Ca/Mg比值显著高于土壤和根系,根系和叶片的N/P、N/K、Ca/K和Ca/Mg均高于土壤。3)不同等级叶片N/P均大于16,表明无翼坡垒植物主要受P限制。PCA分析结果表明,土壤C、全P、全K、全Ca、根系K、Mg、C/K、K/Mg、叶片N、Mg、C/N、C/K、N/K、K/Mg为主要影响因子,土壤全Mg、根系P、Ca、N/P、K/P、叶片Ca、K/P和Ca/K为重要影响因子,反映了无翼坡垒土壤-根-叶C、N、P含量之间以及化学计量比之间也均存在显著相关关系。     

马尾松人工幼林枯枝落叶层的水文特性及养分贮量

为了探明不同林龄马尾松人工林枯枝落叶层现存量、贮水量以及养分贮量的变化规律及其互相之间的关系,在桂西北乐里林场选择3种林龄段马尾松人工林分别建立标准地,对林地枯枝落叶物进行取样测定。结果表明:1)该区9～14a生马尾松人工林枯枝落叶层现存量为3.31～5.64t/hm2,最大净贮水量为4.48～10.19t/hm2,并随林龄的增大而递增。2)林地枯枝落叶层元素养分含量以N,Ca为最大,大约各占10种元素养分总含量的1/3～1/2;Mg,K元素含量次之;Mn,Fe,P,Zn,Cu,B元素含量微小。林地枯枝落叶层养分总贮量为70.66～98.82kg/hm2,随林龄的增大而递增。3)林地枯枝落叶层现存量、最大净贮水量以及元素养分总贮量分别与林龄存在密切的相关性,其回归方程各异。因此,可以根据不同林龄段来预测枯枝落叶层现存量、最大净贮水量和元素养分总贮量。     

大兴安岭兴安落叶松原始林倒木养分含量研究

在大兴安岭兴安落叶松原始林内选择杜香-兴安落叶松林、草类-兴安落叶松林和杜鹃-兴安落叶松林3个典型林型,按照不同树种对倒木的养分含量进行了测定。依据现有的资料,结合研究对象实际,制定了大兴安岭兴安落叶松原始林落叶松和白桦倒木的腐朽等级划分标准。结果表明:不同林型内不同树种倒木有机C、全K、全Na,以及Ca和Mg的含量随着倒木的不断分解均没有明显的变化规律;全N含量均有增加的趋势;全P均保持相对稳定。对3个林型内兴安落叶松倒木的各养分含量之间进行对比,有机C、全K、全P百分含量均为杜鹃-兴安落叶松林﹥草类-兴安落叶松林﹥杜香-兴安落叶松林;全N、全Na和Ca百分含量均为杜鹃-兴安落叶松林﹥杜香-兴安落叶松林﹥草类-兴安落叶松林;Mg百分含量为草类-兴安落叶松林﹥杜鹃-兴安落叶松﹥杜香-兴安落叶松。     

辽宁东部山区红松林、杂木林枯枝落叶营养特性研究

文章以辽东地区两种主要林型——红松林和杂木林为研究对象,研究了两种林型枯枝落叶的养分状况和分配,比较了两种林型在枯枝落叶营养成分及其分配等方面的差异。研究结果如下:①两种林型枯枝落叶养分含量均以全N最高,全P最低,且红松林全N含量高于杂木林。②杂木林内N、P、K归还量都较红松林内多。③两种林分均以叶中的含N量最高,杂木林约占88.6%,红松林约占74.3%。P主要集中在枝和其它(果实、种子)中,K含量以叶为主,且两种林型K含量相差较大。     

不同施肥处理后中林-46杨叶片中营养元素变化趋势研究

通过对不同施肥处理后中林-46杨叶片中营养元素诊断研究表明:(1)不同营养元素浓度具有不同的季节变化趋势。(2)施肥后叶片中营养元素N、P、K相关系数分别为0.8247、0.6930、0.1566,即此林分N、P缺乏,K较丰富;施N肥有利于P、K、Ca、Mg的吸收,施P有利于N、Ca、Mg的吸收,施K有利于N、P、Mg的吸收。(3)N、P、K、Ca、Mg的适宜浓度为1.95%、0.17%、1.33%、0.84%、0.13%。     

石漠化石灰土与水土保持植物葛藤化学元素含量特征

对贵州花溪区石灰土及水土保持植物葛藤化学元素的含量进行了研究.结果表明:(1)石灰土pH值为7.98,有机质含量为56.60 g·kg-1.全N、全P含量分别为3.56,0.64 g·kg-1,N和P有效率低,速效N仅占全N含量的0.47%.速效P仅占全P的1.46%.全K含量为6.92 g·kg-1.属缺K型土壤.全Ca、全Mg含量分别为15.44、2.74 g·kg-1.(2)微量元素含量依次排序为Fe>Mn>Zn>Ni>Pb>Cu>Co>Cd.全Pb、全Zn、全Cu含量均未超过我国土壤环境质量标准(GB15618-1995)中的3级标准,可以作为林地使用.(3)水土保持植物葛藤体内不同元素含量的差异较大,N、K、Ca元素含量在10 g·kg-1以上,P、Mg元素含量为l～6 g·kg-1,Fe元素在1 000 mg·kg-1以上,Zn、Mn、Pb、Cu元素含量为10～100 mg·kg-1,Cd、Ni元素含量<5 mg·kg-1.(4)葛藤对土壤中N、P、K、Ca、Mg元素的积累能力最强,其次是对Zn、Cd,Cu、Pb元素,而对Mn、Ni、Fe元素的积累能力最弱.研究结果可为石漠化石灰土的植被修复提供理论依据.     

海南麻竹林凋落物及养分动态研究

研究了海南麻竹林凋落物量及其养分动态.结果表明:麻竹林凋落物全年总量为6 862.8 kg·hm-2.N、P、K、Ca、Mg的年归还量分别为74.847、3.264、25.921、45.924、11.902kg·hm-2,大小顺序为:N＞Ca＞K＞Mg＞P,养分总的年归还量是161.858kg·hm-2·a-1.凋落物分解失重率达95%的分解期为11.59个月,每年产生的凋落物全部归还于土壤.     

桤木幼林生物量与养分元素的积累特征

通过对林龄1-4年的桤木幼树生物量调查、器官中养分元素N、P、K、Ca、Mg和微量元素Fe、Zn的含量测定及积累量的分析,探讨桤木不同林龄植株的生物量和器官中养分元素分布与积累特征。结果表明,桤木平均木生物量及器官叶、枝、干、根的生物量与年龄呈正相关,生物量增长速率随林龄增加呈下降趋势;各器官生物量构成中,仅干的生物量占单株总生物量的比例随着年龄增加呈上升趋势。桤木器官中养分元素含量NCaKMgPFeZn;N、P、K元素在叶中含量较高,Ca、Mg、Fe元素在根中含量较高。养分元素N、P、K、Ca、Mg、Zn积累量在干中最高,Fe元素积累量在根中最高。桤木林龄1-4年当年养分元素(N、P、K、Ca、Mg)年净积累量分别为17.07 g/株、40.79 g/株、95.82 g/株和106.71 g/株,微量元素(Fe、Zn)当年净积累量分别为335.04 mg/株、577.26 mg/株、1 267 mg/株和1 525.27 mg/株。     

盐分和水分胁迫对落羽杉幼苗的生长量及营养元素含量的影响

采用温室盆栽试验方法 ,研究了不同土壤水分下盐胁迫对 1年生落羽杉实生苗的生长及营养吸收的影响。试验共 12种处理 ,3种水分水平 (W1 ,淹水 ;W2 、W3,土壤含水量分别为田间持水量的 75 %和 2 5 % ) ,每种水分下设 4种盐分处理 (NaCl含量为土壤干重的 0、0 15 %、0 3%和 0 4 5 % ) ,处理时间为 130d。结果表明 :土壤盐分胁迫下落羽杉幼苗的生长及对营养的吸收发生了显著的变化 ,这种变化又因土壤含水量的不同而不同。落羽杉相对高生长、相对地径生长和生物量增量随着土壤盐分浓度的增加和土壤水分含量的减少而减少。在淹水条件下 ,随着土壤盐分浓度的增加 ,落羽杉幼苗根、茎、叶中全N、全P、全Na,以及叶片中的全Ca、全Fe的含量均随着升高 ,而根、茎中的全Fe、全Ca、全Mg含量差异较小。在W2 水分条件下 ,各种盐分处理都在不同程度上增加了根、茎、叶中全N、全Na、全Ca和全Fe含量 ,茎和叶中全P、全K和全Mg含量 ,而根系中的全P、全K和全Mg含量在盐分浓度较高时有所下降。在W3水分条件下 ,各种土壤盐分不同程度地增加了叶片全N、全P和全K含量 ,茎和叶中全Mg和全Ca含量 ,以及根、茎、叶中全Na含量 ,而茎和根中全N、全P和全K含量 ,根、茎和叶中全Fe含量均随着土壤盐分浓度的增加而下降。     

炼山对华西雨屏区杉木林采伐迹地土壤理化特征的影响

炼山在华西雨屏区造林时广泛应用,杉木林采伐迹地炼山后的土壤理化性质研究鲜有报道.本文以华西雨屏区28 a生杉木林（对照）及其采伐迹地为研究对象,通过传统的炼山方式后采样测定土壤pH值、全N、P、K及其有效性以及Ca和Mg含量等,旨在阐明炼山对华西雨屏区杉木采伐迹地土壤的理化性质短期效应.结果表明：炼山能显著提高土壤pH值,能显著增加土壤0～40 cm层的全N含量.不同土层的P含量对炼山的响应不同,炼山后表层土（0 ～20 cm）的全K含量呈现先增加后减少的趋势,中层土（20 cm～40 cm）是先下降、后增加,底层土（40 cm～60 cm）持续下降.炼山后土壤中速效N、有效P的含量均先增加、后降低,而速效K的含量先下降,后增加.炼山后的土壤表层Ca含量显著增加,但对土壤中层和底层土的Ca含量影响趋势无规律.土壤各层中的Mg含量在炼山后明显下降.     

Growth and mineral nutrient analysis of teak (<Emphasis Type="Italic">Tectona grandis</Emphasis>) grown on acidic soils in south China

Teak (Tectona grandis L.f.) is widely planted in the world due to its high market demand, economic, ecological and social value. Its plantations have mostly been established and expanded into sites that are acidic to severely acidic in southern China. But, there are no available and specific evidence-based nutrient management techniques. To better recognize and understand the relationship between teak tree growth and nutrient content in the foliage and soil and establish nutrient norms are critical to optimally manage these young plantations. We studied the foliar nutrient and soil chemistry in 19 representative teak plantations aged 5–8 years. Regression analysis indicated that the mean annual increment of teak volume was linearly and positively correlated with foliar N, Ca, Fe and B concentrations, with soil base saturation percentage, available P and Zn concentrations, and negatively correlated with soil Al concentration. Only if the Ca and Mg contents in soil were enhanced, could the increase in soil base saturation percentage benefit teak growth. A revised classification of low-and high-yielding stands was established by using a sorting method of principal components over 6 foliar macro and 8 micro elements in a Diagnosis and Recommendation Integrated System (DRIS). Specific DRIS norms for teak plantations in acid soils were derived. The nutrient balance of N, P, K Ca, Mg, Zn, B with Fe or Al, Ca with Mg, and Fe with Al provided a key to promote the growth of teak in acid soils. Meanwhile, soil Zn was also found as a primary trace element that affected teak growth in this study.     

Biomass production,nutrient cycling and distribution in age-sequence Chinese fir(Cunninghamia lanceolate) plantations in subtropical China

Biomass production and nutrient(N, P, K, Ca and Mg) accumulation, distribution and cycling were quantified in young, mature and over-mature(10-, 22-, and34-year old) Chinese fir [Cunninghamia lanceolate(Lamb.) Hook] plantations in southern China. Total stand biomass of young, mature and over-mature stands was 38,104 and 138 t ha-1respectively. Biomass production increased significantly with age. Stem wood represented the highest percentage of stand biomass, accounting for 41,55 and 63 % in the young, mature and over-mature plantations respectively. Nutrients concentration was highest in live needles and branches, and lowest in stem wood. The plantations accumulated more N, followed by K, Ca, Mg,and P. Nutrient return amount, nutrient utilization efficiency, nutrient turnover time, the ratio of nutrient returnand uptake increased with stand age, which implies that young Chinese fir deplete soil nutrients to maintain growth,and efficiently utilize nutrients to decrease dependence on soil nutrients as they age. Harvesting young Chinese fir plantations would therefore lead to high nutrient loss, but prolonging the rotation length could improve soil recovery,and help sustain productivity in the long-term. Improved nutrient return through litterfall as stands get older may also be beneficial to nutrient pool recovery.     

辽西干旱地区不同人工林涵养水源的效果分析

从树冠截留雨水效果、枯落物厚度及持水效果等方面对辽西干旱地区4种人工林开展了涵养水源效果分析,结果表明:各人工林树冠对雨水的截留率为15.1％～35.45％,从大到小依次为杨树+沙棘、毛榛纯林、刺槐纯林、杨树纯林;枯落层厚度为1.7～4.0 cm,枯落物贮量为1885.35～6357.25 kg·hm-2,最大持水量为...     

川西高原退化草地的中国沙棘生长及土壤养分研究

以川西高原退化草地人工种植1~3年的中国沙棘为研究对象,分析了其生长、土壤养分及叶片养分回收情况。结果显示:随着种植年限的增加,沙棘幼苗株高、冠幅、叶长及叶宽逐渐升高,侧枝数目和根长先升后降。与同区域康定柳相比,种植3年的中国沙棘根际土壤中全磷、有效磷和有机质含量较高,水解性氮含量相对较低。中国沙棘叶氮、磷含量(Ng、Pg)分别为23.24 mg·g^-1和1.84 mg·g^-1,低于北方典型沙生植物叶片养分水平(27.42 mg·g^-1和3.68 mg·g^-1),叶磷回收效率(PRE)高达69.35%,受土壤有效磷供应不足的影响;康定柳叶磷回收效率为负值,叶氮回收效率(NRE)达59.88%,受土壤有效氮的限制更多,中国沙棘根系固氮作用能够补偿退化草地上土壤氮供应不足的限制。     

Biomass production,nutrient cycling and distribution in age-sequence Chinese fir (<Emphasis Type="Italic">Cunninghamia lanceolate</Emphasis>) plantations in subtropical China

Biomass production and nutrient (N, P, K, Ca and Mg) accumulation, distribution and cycling were quantified in young, mature and over-mature (10-, 22-, and 34-year old) Chinese fir [Cunninghamia lanceolate (Lamb.) Hook] plantations in southern China. Total stand biomass of young, mature and over-mature stands was 38, 104 and 138 t ha^?1 respectively. Biomass production increased significantly with age. Stem wood represented the highest percentage of stand biomass, accounting for 41, 55 and 63 % in the young, mature and over-mature plantations respectively. Nutrients concentration was highest in live needles and branches, and lowest in stem wood. The plantations accumulated more N, followed by K, Ca, Mg, and P. Nutrient return amount, nutrient utilization efficiency, nutrient turnover time, the ratio of nutrient return and uptake increased with stand age, which implies that young Chinese fir deplete soil nutrients to maintain growth, and efficiently utilize nutrients to decrease dependence on soil nutrients as they age. Harvesting young Chinese fir plantations would therefore lead to high nutrient loss, but prolonging the rotation length could improve soil recovery, and help sustain productivity in the long-term. Improved nutrient return through litterfall as stands get older may also be beneficial to nutrient pool recovery.     

造林对铁尾矿地养分含量及物种多样性的影响

金属矿产开采过程中形成的大量尾矿给当地带来了严重的生态环境问题,因此对于尾矿的生态治理一直是人们关注的焦点(蓝崇钰等,1996;束文圣等,2000;郝秀珍等,2005)。铁尾矿是尾矿的一种,它是由铁矿石直接粉碎而成,其物理化学性质与普通土壤有很大不同,给生态治理带来很大困难。从     

黑龙江省西部低山丘陵区水土保持林模式构建及效益

在黑龙江省西部选择典型低山丘陵区,根据其立地类型试验构建了樟子松纯林、樟子松蒙古沙棘林、蒙古沙棘林、云杉落叶松林、小黑杨林、灌木柳林等6种水土保持林示范模式,并对其生长状况及水土保持效益进行了试验观测。结果表明:各类试验林总体成活率为87%,保存率为82%,模式区内林木覆盖度已达70%,开始发挥效益:试验前原来的19条水流沟中15条发展沟已变为稳定沟,模式建立成型后较对照减少地表径流量39.7%～95.9%,减少土壤流失量63.7%～99.5%,减少肥料流失量63.9%～99.5%;与造林前土壤养分含量相比,模式区有机质含量提高46%～59%,有机氮提高24%～52.2%,有效磷提高48.6%～60.7%;试验区内物种多样性较试验造林前明显增加。     

不同造林措施对桉树人工林地土壤养分的影响

针对桉树人工林地力退化问题,通过比较两种造林措施下桉树人工林地土壤肥力特征发现,皆伐和造林时的人为活动对浅土层(0～20 cm)的土壤有松动作用,在一定程度上降低土壤容重,部分提高土壤持水量和孔隙度,但造林后林地土壤物理特性变差,炼山+机械挖桩造林措施对林地土壤物理性质破坏作用要明显高于伐根催腐造林;与皆伐前相比,两种造林措施均导致了林地土壤pH向酸性化方向发展;伐根催腐造林使得林地土壤有机质含量、全N、全K、Ca和Mg含量均较皆伐前大,炼山措施导致大量养分烧失和流失,故其最小;土壤微量元素中除了Cu以炼山造林地最大外,Fe、Mn、Zn、B均以伐根催腐造林地最大。     

Nutrient cycling and distribution in different-aged plantations of Chinese fir in southern China

The distribution in tree biomass and understorey vegetation and annual biological and geochemical cycling of total nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) were measured in young, middle-aged and mature plantations (8-, 14- and 24-years old) of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) in southern China. Although >98% of nutrients occurred in the soil, soil nutrient content decreased with plantation age. Nutrient outputs from the soil exceeded inputs in stands of all ages but the net soil nutrient loss increased significantly for N, P and Ca with plantation age. Comparison of nutrient fluxes showed that the smallest (and hence limiting for nutrient cycling) fluxes were litter decomposition in the young plantation in contrast to canopy fluxes (apart from for Mg) in the middle-aged and mature plantations. Nutrient use efficiency, release of nutrients from litter decomposition and nutrient return, particularly in litterfall, increased significantly with plantation age. These results suggest that, as stand age increases, nutrient cycling in Chinese fir plantations is increasingly dominated by biological processes and becomes less dependent on external nutrient sources in rainfall and the soil. It therefore appears that prolonging the rotation length of Chinese fir plantations by approximately 5 years could be beneficial for maintaining the soil nutrient status for successive plantings.     

秃杉林与杉木连栽林的土壤理化性质及林木生长量比较

选择在杉木1代林采伐迹地上营造的8,11和14年生秃杉林及8,11和14年生杉木连栽2代林进行土壤理化性质及林木生长量对比试验。结果表明:8,11和14年生秃杉林地土壤密度依次为0.893～1.112,0.797～1.256和0.598～1.211g.cm-3,比杉木林下降0.9%～6.9%;3个林龄秃杉林地土壤总孔隙度依次为45.69%～65.33%,46.45%～68.74%和39.82%～68.26%,比杉木林提高6.6%～8.7%;3个林龄秃杉林地土壤通气度依次为3.43%～11.43%,4.15%～19.73%和2.28%～12.23%,比杉木林提高14.2%～24.4%;3个林龄秃杉林地土壤饱和持水量依次为46.89%～66.50%,40.90%～68.09%和42.36%～98.15%,比杉木林提高12.4%～14.9%;3个林龄秃杉林地土壤pH值依次为4.30～5.10,4.40～4.80和4.13～4.55,比杉木林降低1.3%～6.3%;3个林龄秃杉林地土壤有机质含量依次为46.03～71.45,34.96～68.67和25.59～79.38g·kg-1,8年生比杉木林略低,11和14年生...