Effects of heavy metal pollution on soil microbial biomass

１Ｉｎｔｒｏｄｕｃｔｉｏｎ１．１ＢａｓｉｃｃｏｎｃｅｐｔｏｆｍｉｃｒｏｂｉａｌｂｉｏｍａｓＳｏｉｌｍｉｃｒｏｂｉａｌｂｉｏｍａｓｉｓｄｅｆｉｎｅｄａｓｔｈｅｌｉｖｉｎｇｐａｒｔｏｆｓｏｉｌｏｒｇａｎｉｃｍａｔｅｒ，ｅｘｃｌｕｄｉｎｇｐｌａｎｔｒｏｏｔ...     

牡丹江海浪河水栉霉总量调查与分析

由于牡丹江市海浪河水质污染，造成水栉霉大量繁衍，影响了牡丹江市西水源正常供水，引起各有关方面的高度重视。为控制、消除水栉霉的影响，为领导决策提供科学依据，我们对海浪河水栉霉总量进行了调查与分析，经全流域徒步沿河调查、采样分析、统计，计算出水栉霉生物总量。统计表明海浪河从河夹水坝至入牡丹江河口，水栉霉生物量呈递减趋势。控制有机污染是抑制水栉霉大量繁衍的最有效手段。     

Winter losses of nitrogen and phosphorus from Italian ryegrass, meadow fescue and white clover in a northern temperate climate

We have studied to what degree Italian ryegrass (Lolium multiflorum Lam.), white clover (Trifolium repens L.) and meadow fescue (Festuca pratensis L.) are able to preserve nitrogen (N) and phosphorous (P) in shoots and roots from one growing season to the next in a northern temperate climate. Field experiments were performed during four consecutive winters in central southeast Norway (60°42′N, 10°51′E), and N and P in plant biomass were measured in the autumn and in the spring. We also measured the contents of total N, total P and organic carbon (C) in seepage water that percolated through the aboveground plant material. Uptake of N and P in Italian ryegrass and white clover was substantially larger than in meadow fescue. The winter losses varied greatly from year to year, depending on the winter climate. On the average for all three of the plant species, the winter losses of N from aboveground biomass were 6, 35, 68 and 10% in the four experimental years, respectively. The corresponding P losses were 11, 36, 60 and 22%. On the average for all plant species and experimental years, 43 (±12)% (S.E., n = 12) of the N, 34 (±9)% of the P and 4 (±1)% of the C that was lost from the aboveground plant biomass during the winter, was recovered in seepage water, basically as a nutrient pulse in melt water in early spring. The very low C recovery rate in seepage water suggested a considerable microbial growth on lost plant C. Assuming that all un-recovered plant C was consumed by microorganisms not included in measurements of the seepage water, modelling showed that microbial immobilisation theoretically might explain the unexpectedly low recovery rates of N and P. The study was not designed to investigate the possible effects of psychrophilic microbes on N and P cycling. Therefore, it is inconclusive and underlines the need for more knowledge on this matter.     

稀土对红壤微生物量影响的初步研究

本文研究了不同稀土元素在不同浓度水平下红壤（黄筋泥）中微生物量的变化规律。结果表明，不同稀土元素对土壤微生物量具有相似的影响效应：在低稀土浓度条件下土壤微生物量升高，随稀土浓度的升高土壤微生物量显著降低。但不同稀土元素使微生物量降低的程度各异，并初步求得黄筋泥中稀土元素对微生物的毒性浓度可能在（90～180）×10(－6)范围内。     

Impacts of ozone on the biomass and yield of rice in open-top chambers

ＩｎｔｒｏｄｕｃｔｉｏｎＯｚｏｎｅ(Ｏ3)ｆｏｒｍｅｄａｓｐｈｏｔｏｃｈｅｍｉｃａｌｓｍｏｇｉｓｔｈｅｍｏｓｔｄａｎｇｅｒａｎｄｗｉｄｅｓｐｒｅａｄｃｏｍｐｏｎｅｎｔｉｎｔｈｅａｉｒｐｏｌｌｕｔｉｏｎ.Ｎｏｗａｄａｙｓ,ｔｈｅｔｙｐｉｃａｌｄａｉｌｙｍａｘｉｍｕｍＯ3ｃｏｎｃｅｎｔｒａｔｉｏｎｓｉｎｕｒｂａｎｓｕｂｕｒｂａｎａｎｄａｒｅａｓｈａｖｅｒｅａｃｈｅｄ100～400ｎｌ/Ｌａｎｄ50～120ｎｌ/Ｌ,ｒｅｓｐｅｃｔｉｖｅｌｙ.Ｕｎｄｅｒｃｅｒｔａｉｎｍｅｔｅｏｒｏｌｏｇｉｃａｌｃｏｎｄｉｔｉｏｎｒｕｒａｌ…     

Net Ecosystem Production of Boreal Larch Ecosystems on the Yenisei Transect

The study was carried out in the Turukhansk Research Station of Yenisei Transect (65^°46^′N, 89^°25^′E). Larch (Larix gmelinii (Rupr.) Rupr.) is the dominant overstory tree species. The research has been conducted on four permanent test plots in same-age mature (110-year old) and overmature (380-year old) post-fire larch stands of green moss and lichen groups of forest type. Carbon cycle parameters were assessed based on a biometric method. Quantitative analysis of carbon pools and fluxes shows that net ecosystem production of north taiga larch stands averages 32% of net primary production. Sink of atmospheric CO₂ makes 1.22 and 0.74 t C ha^{− 1} year^{− 1} for mature and overmature green moss larch stands, and 0.65 and 0.35 t C ha^{− 1} year^{− 1} for lichen type. Net carbon sink in the tree layer make up 9% of net primary production carbon, ground vegetation – 15%, and dead plant residues accumulation – 8% of atmospheric carbon uptake via photosynthesis.     

Intra-specific variations of two Leymus chinensis divergence populations in Songnen Plain, Northeast China

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｉｎｔｒａ ａｎｄｉｎｔｅｒ ｓｐｅｃｉｆｉｃｖａｒｉａｔｉｏｎｓｏｆｐｌａｎｔｐｏｐｕｌａｔｉｏｎｓｈａｖｅｂｅｅｎｗｅｌｌｄｏｃｕｍｅｎｔｅｄｆｏｒｍａｎｙｐｌａｎｔｐｏｐｕｌａｔｉｏｎｓ (Ｂａｓｓｏｗ ,1 997;Ｃａｌｌａｗａｙ ,1 994;Ｄｅｌｐｈ ,1 993;Ｆｏｒｄ ,1 981 ;Ｊｏｎｅｓ,1 999;Ｍｏｎｓｏｎ ,1 989;Ｐａｖｏｎｅ ,1 985;Ｖａｖｒｅ,1 997) .Ｈｏｗｅｖｅｒ,ｍｏｓｔｏｆｔｈｅｓｔｕｄｉｅｓｆｏｃｕｓｅｄｏｎｉｎｔｅｒ ｓｐｅｃｉｆｉｃｖａｒｉａｔｉｏｎｓｉｎｍａｌ…     

川东高海拔山区红三叶、红三叶─鸭茅和红三叶─黑麦草人工群落生物量的比较研究

红三叶牧草作为一个优良牧草品种，在川东高海拔山区表现尤为突出。本文就红三叶、红三叶─鸭茅和红三叶─黑麦草三个人工群落进行了比较系统的生物量观测，比较了三个群落的总生物量、地上生物量、地下生物量特点，分析了各群落生物量在不同部位的分配情况，垂直空间上的配置，以及各器官在垂直空间上的配置和各个群落的茎、叶、花、立枯在垂直空间上所构成的分布带谱，通过以上分析发现，红三叶─黑麦草群落的总生物量最高，为４６．４７ｋｇ／ｈａ，其中地上部分为２４．５７ｋｇ／ｈａ，而红三叶─鸭茅群落的地下部分最为发达，地下生物量达２４．７４ｋｇ／ｈａ。根据群落生产结构，发现以红三叶为主的人工群落，其生产结构为不规则塔型分布，在离地面２０─４０ｃｍ处，生物量有一个高峰，并且红三叶─黑麦草群落的地上、地下生物量在垂直空间上分布较为均匀，其生产结构较为合理。通过各器官垂直空间分布分析，发现茎主要分布在４０ｃｍ以下，叶量最大是在４０ｃｍ左右，生殖器官最大量在５０ｃｍ附近，并且根据群落的茎：叶：花（穗）：立枯垂直分布带谱可以发现，各个器官在不同层次中所处的地位，而且根据此带谱可以掌握草地的刈割时间和刈割高度。     

Simple rules for measuring changes in ecosystem carbon in forestry-offset projects

There is growing interest in the useof forestry-offset projects to mitigate increasingconcentrations of carbon dioxide in the atmosphere. If forestry-offset projects are to be employed broadlyand successfully there need to be accounting rulesthat are easy to operationalize and effective inpreventing cheating. Since carbon is both tangibleand predictable in where it occurs it is feasible todevelop simple accounting rules. Such rules must beconservative with respect to the amount of carboncredited.If accounting practices based on the following simplerules are employed, costs will be kept low andprojects will credit only carbon that is physicallypresent:Changes in living aboveground biomass must always be measured in forestry –offset projects.Belowground living biomass can be estimated from aboveground living biomass in forestry-offset projects. Generalized root/shoot ratios can be used as long as conservative ratios are applied.Not all changes in soil carbon stocks need to be measured, only those for which there is a possibility the stock is declining.The necromass pool need not be measured except when there has been a recent disturbance (interval varies with ecosystem). To insure that inaccurate techniques do not lead to overestimating of carbon stock changes, imprecise estimates of the carbon content of an ecosystem compartment should be discounted.There should be no required level of accuracy associated with estimates of carbon stock changes in forestry-offset projects, but the creditable carbon should be discounted proportional to the uncertainty.     

红树林区硅藻丰度和生物量构成及与底栖动物的关系

对深圳福田红树林湿地中百亩区、上沙、下沙、沙嘴、观鸟亭等5个亚区中的硅藻种类、丰度和生物量等进行了研究。结果显示，5区中硅藻门藻类在种类及丰度组成上均为优势类群。硅藻总生物量以观鸟亭最高，达25．076mg/L,下沙8．446mg／L，百亩区4．488mg／L，沙嘴2．111mg／L，上沙仅为0．742mg／L。最高与最低硅藻总生物量相关可达38倍。生物量份布趋势和其丰度分布相似，相关系数为0．998，但每一种硅藻生物量之间存在较大差异。硅藻生物量及丰度与底栖动物总密度分布之间呈负相关性。