溶胶-凝胶法制备Y_3Al_5O_(12)超微粉末

使用溶胶-凝胶法制备了平均粒径为20～150nm的Y_3Al_5O_(12)超微粉末。从凝胶至超微粉末的过程中,发生了较大的失重现象。纯相晶态的Y_3Al_5O_(12)超微粉末的最低生成温度为900℃。粉末平均粒径随着灼烧时间的增加而逐渐增大,随着灼烧温度的增加而显著增大。

稀土对铜抗氧化性能的影响

铜易被空气氧化,尤其在热加工过程中。铜的氧化动力学已有报道。加入稀土元素可提高铜在500～900℃时的抗氧化能力。本文研究了含轻稀土的铜在室温至熔化状态下的氧化过程,并对氧化膜的成分及氧化机理进行了探讨。

一个新的CuxSbOy化合物的合成

在研究Bi系超导样品中各组分间的相图关系时,我们发现了一个新的Cu_xSbO_y化合物。关于Cu—Sb—O体系只有CuSb_2O_5化合物已见报导1 实验部分试样制备采用固相反应方法,将Sb_2O_3,CuO(A,R级)混匀、碾磨,于900℃在刚玉坩锅中灼烧24小时。X—ray衍射分析在日本D/max—Ⅱв衍射仪上进行

PHYLOGEOGRAPHIC PATTERNS INDICATE TRANSATLANTIC MIGRATION FROM EUROPE TO NORTH AMERICA IN THE RED SEAWEED CHONDRUS CRISPUS (GIGARTINALES, RHODOPHYTA)1

Inferring how the Pleistocene climate oscillations have repopulated the extant population structure of Chondrus crispus Stackh. in the North Atlantic Ocean is important both for our understanding of the glacial episode promoting diversification and for the conservation and development of marine organisms. C. crispus is an ecologically and commercially important red seaweed with broad distributions in the North Atlantic. Here, we employed both partial mtDNA Cox1 and nrDNA internal transcribed spacer region 2 (ITS2) sequences to explore the genetic structure of 17 C. crispus populations from this area. Twenty-eight and 30 haplotypes were inferred from these two markers, respectively. Analysis of molecular variance (AMOVA) and of the population statistic Theta(ST) not only revealed significant genetic structure within C. crispus populations but also detected significant levels of genetic subdivision among and within populations in the North Atlantic. On the basis of high haplotype diversity and the presence of endemic haplotypes, we postulate that C. crispus had survived in Pleistocene glacial refugia in the northeast Atlantic, such as the English Channel and the northwestern Iberian Peninsula. We also hypothesize that C. crispus from the English Channel refugium repopulated most of northeastern Europe and recolonized northeastern North America in the Late Pleistocene. The observed phylogeographic pattern of C. crispus populations is in agreement with a scenario in which severe Quaternary glaciations influenced the genetic structure of North Atlantic marine organisms with contiguous population expansion and locally restricted gene flow coupled with a transatlantic dispersal in the Late Pleistocene.

Establishment of a micro-particle bombardment transformation system for Dunaliella saliva

In this study, we chronicle the establishment of a novel transformation system for the unicellular marine green alga, Dunaliella salina. We introduced the CaMV35S promoter-GUS construct into D. saliva with a PDS1000/He micro-particle bombardment system. Forty eight h after transformation, via histochemical staining, we observed the transient expression of GUS in D. salina cells which had been bombarded under rupture-disc pressures of 450 psi and 900 psi. We observed no GUS activity in either the negative or the blank controls. Our findings indicated that the micro-particle bombardment method constituted a feasible approach to the genetic transformation of D. salina. We also conducted tests of the cells' sensitivity to seven antibiotics and one herbicide, and our results suggested that 20 mu g/ ml of Basta could inhibit cell growth completely. The bar gene, which encodes for phosphinothricin acetyltransferase and confers herbicide tolerance, was introduced into the cells via the above established method. The results of PCR and PCR-Southern blot analyses indicated that the gene was successfully integrated into the genome of the transformants.

Molecular phylogeny and species identification of pufferfish of the genus Takifugu (Tetraodontiformes, Tetraodontidae)

The phylogenetic relationships and species identification of pufferfishes of the genus Takifugu were examined by use of randomly amplified polymorphic DNA (RAPD) and sequencing of the amplified partial mitochondrial 16S ribosomal RNA genes. Amplifications with 200 ten-base primers under predetermined optimal reaction conditions yielded 1962 reproducible amplified fragments ranging from 200 to 3000 bp. Genetic distances between 5 species of Takifugu and Lagocephalus spadiceus as the outgroup were calculated from the presence or absence of the amplified fragments. Approximately 572 bp of the 16S ribosonial RNA gene was amplified, using universal primers, and used to determine the genetic distance values. Topological phylogenic trees for the 5 species of Takifugu and outgroup were generated from neighbor-joining analysis based on the data set of RAPD analysis and sequences of mitochondrial 16S rDNA. The genetic distance between Takifugu rubripes and Takifugu pseudommus was almost the same as that between individuals within cacti species, but much smaller than that between T. rubripes, T. pseudommus, and the other species. The molecular data gathered from both analysis of mitochondria and nuclear DNA strongly indicated that T. rubripes and T. pseudommus should be regarded as the same species. A fragment of approximately 900 bp was amplified from the genome of all 26 T. pseudommus individuals examined and 4 individuals of intermediate varieties between T. rubripes and T. pseudommus. Of the 32 T. rubripes individuals, only 3 had the amplified fragment. These results suggest that this fragment may be useful in distinguishing between T. rubripes and T. pseudommus.

Algal biotechnology industries and research activities in China

In old China there were very few people engaged in the study of the algae, but in new China, freshwater and marine algae are studied by over one hundred old and new phycologists. There is now an algal biotechnology industry consisting of an aquaculture industry, producing large amounts of the seaweeds Laminaria, Porphyra, Undaria, Gracilaria, eucheumoids, and the microalgae Dunaliella and Spirulina. There is also a phycocolloid industry, producing algin, agar and carrageenan; an industry producing chemicals and drugs, such as iodine, mannitol, phycocyanin, beta -carotene, PSS (propylene glycol alginate sulfate) and FPS (fucose-containing sulfated polysaccharides) and an industry producing food, feed and fertilizer. The Laminaria cultivation industry produces about 900,000 t dry Laminaria, probably the largest producer in the world and 13,000 t algin, undoubtedly one of the largest algin producer in the world.

There are two 5 '-flanking regions of bkt encoding beta-carotene ketolase in Haematococcus pluvialis

The unicellular green alga Haematococcus pluvialis accumulates a commercially valuable astaxanthin, with levels reaching up to 4% dry weight under environmental stress. In recent years, much effort has been devoted to understanding the molecular mechanisms regulating astaxanthin biosynthetic pathways. Beta-carotene ketolase (bkt), with control being exhibited at the transcription level, plays an important role in astaxanthin biosynthesis by H. pluvialis. Here we demonstrate the presence of two separate 5'-flanking regions [1.5 kilobase (kb) and 2 kb] of bkt (bkt1 and bkt2) that possess regulatory elements similar to those of known stress-responsive genes in plants. Results of 5'-deletion constructs and transient beta-galactosidase expression assays demonstrate that there may be positive regulatory elements governing expression in the shorter promoter at -1060/-900 from the 1.5 kb 5' region, and in the longer promoter at -1838/-1219 and at -1046/ -734 from the 2 kb 5' region relative to each homologous ATG start codon. Furthermore, our present studies reveal that the first intron (+371/+497) downstream from the 1.5 kb 5' untranslated region of bkt1 may function as a negative regulatory element to regulate its own promoter.

Geological records of marine environmental changes in the southern Okinawa Trough

Indexes of sediment grain size, sedimentation rates, geochemical composition, heavy minerals, benthic foraminiferal fauna, indicator species of the Kuroshio Current, paleo-SST and carbonate dissolution of core E017 conformably suggest a great marine environmental change occurring at about 10.1-9.2 cal. kaBP in the southern Okinawa Trough, which may correspond to the strengthening of the Kuroshio Warm Current and re-entering the Okinawa Trough through the sea area off northeast Taiwan. The invasion of Kuroshio current has experienced a process of gradual strengthening and then weakening, and its intensity became more fluctuation during the last 5000 years. Compared to the transition of sediment grain size, geochemical composition and heavy minerals, the foraminiferal faunas show a 900-year lag, which may indicate that the invasion of Kuroshio Current and the consequent sea surface and deep-water environmental changes is a gradual process, and fauna has an obvious lag compared to environment altering. The carbonate dissolution of the Okinawa Trough has had an apparent strengthening since 9.2 cal. kaBP, and reached a maximum in the late 3000 years, which may be caused by the deep-water environmental changes due to the invasion of Kuroshio Current.

青岛市区辐射环境质量评价

安全环境是人类赖以生存的基础，天然放射性辐射环境是人类生存环境的重要组成部分，放射性物质存在于各类物质中，包括空气、水源和土壤等。放射性物质的辐射对环境的影响往往被人们所忽视，但又是最危险的环境影响因素。为了生存和健康不仅需要了解重金属和有机物污染，而且需要了解辐射污染。 天然放射性辐射环境与该区域内的地质环境密切相关。青岛地区燕山期岩浆活动频繁，形成了以钾长花岗岩和二长花岗岩为主的大规模侵入岩体，大多数母岩为富含铀、钍的花岗岩。本论文选择青岛地区做为放射性的研究区，该花岗岩地区与放射性核素的辐射强度的关系具有典型的代表性。 论文在大量密集测量地表岩石、土壤γ总量、土壤中238U、232Th 、40K放射性核素的含量基础上，分析了天然放射性辐射环境与该区域内的地质环境. 分析了环境中氡的来源及迁移机制，给出了氡的运移理论模型，指出了环境中氡的危害及其土壤中的分布与地质环境的关系。分别从内照射和外照射的角度，将土壤中238U (226Ra) 、232Th 、40K放射性核素的比活度、γ能量谱、环境中的氡浓度和直接测量空气中的吸收剂量率相结合，首次对青岛地区的辐射环境进行了研究和评价，可为奥运和青岛市长远发展提供科学保障。 结果表明研究区内土壤中的238U含量低于全国及世界平均值，土壤中232Th含量分别是全国和世界均值含量的1.1和1.5倍, 土壤中40K含量分别是全国和世界均值含量的2.43和2.44倍，因此空气中的吸收剂量率高于全国（81.5nGy•h-1）和世界（80 nGy•h-1）约1.2倍。通过能谱估算的空气吸收剂量率与实际测量值近似相等。研究区的年有效剂量为0.83 mSv，低于世界平均年有效外部照射的剂量限值1.0mSv，外照射指数和内照射指数均小于1，该区的等效镭浓度Raeq均值为197 Bq•kg-1，低于建议最大容许值370 Bq•kg-1，基于以上的各类指标均在世界均值或容许值范围内，可以认为该区的外照射水平属于安全辐射范畴。 222Rn浓度对人体内部照射具有举足轻重的地位，也是评价辐射环境质量的关键所在。本文采用经典的氡在空气中的扩散和对流的理论模式，通过研究区内的土壤中铀的含量推算出离地面1米高的空气中的氡的浓度，并且分析了土壤中的氡浓度与土壤中的放射性核素U、Th、K的含量的关系。研究区的土壤氡浓度总体平均值为5887Bq/m3，与全球土壤氡浓度的平均值7400 Bq/m3相比属于土壤氡浓度正常地区。由于青岛市区土壤覆盖层很薄,地表储气条件较差，造成土壤氡逸散。因此除区内土壤氡浓度几处偏高区以的其他区域，甚至断裂带上他和其他区域的土壤氡浓度也普遍偏低。通过计算可以得出青岛市区大气中氡浓度所导致的居民室外吸入氡子体所产生的年均人有效剂量估算结果是0.94mSv/a。这与联合国辐射防护委员会公布世界平均本底值1.2mSv/a相比,此值在正常范围内。 这个地区虽然大面积出露富含放射性物质的花岗岩，由花岗岩风化形成的土壤中放射性核素含量（钍、钾）也较高，但是因为铀含量不高，另外本区临海，一年四季的风速较大，因此本地区室外和室内空气中氡浓度不高。 综上可以得出结论：本区的辐射环境属于安全区域，适于人类生活。 本论文研究成果和创新点有：首次在大量密集测量的基础上，系统地对青岛地区的辐射环境进行了研究和评价；在数据采集方面，采用直接就地测量，跟其他调查方法比，采样密度大，数据量大。从研究方法方面，本文从外照射和内照射的角度，采用了多指标相结合的综合方式来评价本区的辐射环境质量，详实可信；引入GIS技术，和放射性评价相结合，较为系统深入地探讨了放射性核素和氡浓度的分布特征及其与岩性的关系。

中国近海栉孔扇贝群体遗传结构及遗传变异与生长的关系

本文以凝胶电泳方法，以等位基因酶和可溶性蛋白为探针研究了中国近海栉孔扇贝(Chlamys farreri)5个不同自然分布群体的遗传结构及遗传变异与生长的关系。在所研究的23个位点中，只有Mdh-1在5个群体中为纯合状态，其余位点都不同程度地处于多态或杂合态。大多数位点的等位基因及基因型分布频率都处在不平衡状态。对各位点的D值检验表明，大多数位点都杂合子缺失。杂合子过剩或处于Hardy-Weinberg平衡的位点为19.64-22.32%。杂合度以海洋岛和长岛群体最高，都是0.304，荣成和大连群体次之，分别为0.290和0.287，青岛群体为0.219。位点有效等位基因数及密码子差数在群体间的变化与杂合度基本一致。用这三个参数构建的遗传变异综合评价指数在这5个群体从北至南依次为0.726，0.542，0.658，0.547和0.133。多态位点比例在P ≤ 0.99水平下，海洋、大连、长岛及荣成4个群体都在0.800以上，仅青岛群体为0.565。在Est7个位点从高纬度向低纬度在等位基因数目上存在梯度递减渐变性。在某些等位基因的分布频率或从高纬度或从低纬度向相对方向递变。除了单向渐变外，也存在双向渐变现象。栉孔扇贝这5个群体在遗传相似性方面基本上是群体间的差异（I > 0.900）。相比之下，大连、长岛两群体间的相似性最大。由于辽东沿岸流和黄海冷水团的作用，海洋岛群体与邻近群体的基因交流较差，使之在遗传上相对较为独立。从遗传变异不平、杂合子缺失特征及等位基因的渐变性也证明，该群体已具相当程度的分化，这主要是由于环境隔离所造成的“孤岛效应”的结果。通过对5个群体形态数量性状生与群体遗传变异的比较表明，遗传变异不平较高的群体，其生长速度也较快，二者基本呈平行关系，唯海洋岛与长岛的结果相悖，其原因可能与两海区间初级生产力水平有关。从个体杂合度与第一年生长壳高关系的研究可以发现，海洋、大连和青岛群体在杂合度与生长间基本呈正相关关系，而在长岛与荣成群体内存在杂合度与生长具不同相关性的子群体，并证明个体杂合度超过0.300以上，其与生长的关系基本上处于不定向状态。在环境和遗传双重压力下，青岛群体的变异水平较低。

热带西太平洋环流动力结构分析与模拟

热带西太平洋环流是副热带环流与热带环流关键分量，毗邻西太平洋暖池，对暖池的形成与变化有重要的作用。然而，目前为止，热带西太平洋环流还有许多问题，包括动力结构还不清楚。因此，论文针对热带西太平洋环流的研究不仅在太平洋环流动力学上有理论意义，而且对气候变化的研究和预测也具有理论和实用价值。 太平洋北赤道流分叉是大洋，特别是太平洋西部边界流海域的一个非常突出的环流现象，它是大洋中副热带大流环和热带流环的发源地，很大程度上决定着海盆尺度的大洋环流结构，在大洋环流动力学上具有非常重要的意义和地位；同时它决定着大洋西边界区质量、热量的经向输送，进而对气候变化产生重要影响，是气候系统中不可忽视的重要分量。因此，北赤道流分叉的研究，不仅具有在海洋动力学上科学意义，而且对气候变化和预测也有实践意义。 从30年代至今，关于北赤道流分叉的研究有两种，一是根据实际观测水文数据，二是由数值模拟结果得出结论。用观测数据做出的结果，相对比较接近实际，但资料的分辨率较差，会引起估算结果的偏差；数值模拟结果有较高的时空分辨率，但由于模式本身的某些缺点会导致结果偏离实际。目前为止，诸多有关北赤道流分叉的结果，如分叉纬度变化的结论很不一致。所以，如何找到一种高时空分辨率的数据或提出一个比较符合物理实际并得到实测数据验证的数值模式是研究北赤道流分叉的关键。 本文用1992年10月到2004年12月高时空分辨率的卫星高度计数据，通过计算迹线的方法，确定了北赤道流分叉的纬度。结果表明，年平均分叉纬度约在13.4°N. 关于北赤道流分叉的季节变化，6月份发生在最南端（12.9°N），12月份发生在最北端（14.1°N）。12年的平均结果显示，7月份的分叉纬度比6月份和8月份明显偏大，这是局地风应力旋度导致的结果。本文同时研究了北赤道流分叉的年际变化，结果表明在厄尔尼诺年，北赤道流分叉纬度北移，在拉尼娜年，分叉纬度南移。 在热带西太平洋地区，特别是西边界流区和印度尼西亚贯通流邻近海域，岛屿众多，地形非常复杂，历史水文数据和测流数据又极少，所以几乎无法用分析观测数据的方法求得这一海域海洋环流，特别是次表层环流结构的深刻了解。因此，本文利用一个既适用于开阔大洋又适宜于地形变化剧烈海域的混合坐标海洋模式HYCOM，模拟了热带西太平洋环流，特别是西边界流及其相关海流，如，新几内亚沿岸潜流、棉兰老潜流、赤道潜流和印度尼西亚贯通流的气候态及其月、季变化。模式结果再现了该海域主要流系及其季节变化，模拟得到的海面高度场与卫星高度计数据基本一致；模拟所得的诸多关键断面上的海流、温度和盐度结构与实地观测数据（Johnson et al., 2002）有良好的一致性，说明本文的HYCOM模拟结果是比较可信、可靠的，可以用来做西太平洋环流分析用。本文得到结果如下： （1）赤道潜流究竟起源于何处，是赤道环流动力学上一个重要问题。鉴于实测数据缺乏和赤道潜流起源邻近海域地形复杂，相关研究很少，仅有的几项研究结果认为赤道潜流起源于135－137°E。本文一系列经向跨赤道断面的纬向流速模拟结果表明，赤道潜流最西源于129－130°E之间；另外，事实上，从200米层水平环流的模拟结果来看，赤道潜流有4个源头，各季有所不同：(i) 新几内亚沿岸潜流在135°E附近汇入赤道潜流；与Tsuchiya et al.（1989）结论相同；(ii) 来自棉兰老海流，这与Lu and McCreary（1995），Gu and Philander（1997）结论相同；(iii) 南海水经民都洛海峡、苏禄海和苏拉威西海西部由哈马黑拉岛以北进入赤道潜流，特别是，在春、夏、秋季；(iv) 印度洋海水经班达海和马鲁古海沿苏拉威西东岸北上沿哈马黑拉岛以东汇入赤道潜流（特别是春季）。所以，赤道潜流就水源来说，它有来自南海、印度洋和棉兰老以东的海水，就其起源来说，还是应该算从129－130°E开始的。 （2）棉兰老潜流发现于80年代末，尽管棉兰老潜流的起源对这一海域环流动力学非常重要，但由于资料缺乏，其起源的研究甚少。本文的模拟结果表明棉兰老潜流似乎有一部分水来自棉兰老海流，这主要在300－500米层。但更重要的是，从马鲁古海西边界（苏拉威西岛以东）向北的一支流更是棉兰老潜流的重要水源，说明棉兰老潜流的水源有相当部分是来自南半球，在600，700米层，特别是800，900和1000米层，棉兰老海流流速急剧减小至几乎看不到，而棉兰老潜流非常突出，其水源主要来自南半球苏拉威西岛东部向北的流动。至于棉兰老潜流的去处，500，600米层的模拟结果显示，棉兰老潜流在12－13°N附近，一大部分向东流去，一小部分向南加入棉兰老海流。在700米层以下，棉兰老潜流则在12°N向东流去，这与Hu and Cui（1989, 1991）和Wang and Hu（1998）的结果一致。 （3）关于印度尼西亚贯通流。HYCOM模拟的印度尼西亚贯通流年平均状况指出：250米以浅，印度尼西亚贯通流由西太平洋主要经由望加锡海峡进入东印度洋；300米以深，印度尼西亚贯通流反向，由东印度洋经由弗罗勒斯海、班达海和马鲁古海的西部边界进入太平洋。由200米层环流可以看出，从民都洛海峡南下的南海水是进入望加锡海峡构成印度尼西亚贯通流的主要的来源，另一小部分来自棉兰老海流。 （4）关于黑潮南海分支。在本文的模拟结果中，一年四季都有明显的黑潮分支由吕宋北端向西北进入南海后，沿大约21°N附近向西南流动，宽约100－200公里，深达300－400米，最大流速一般可达20厘米/秒，最大在冬季，可达40厘米/秒，流量约为6.5Sv，冬季强，5、9月份偏弱。证明了仇德忠、杨天鸿、郭忠信（1984）和郭忠信、杨天鸿、仇德忠（1985）关于南海黑潮分支存在的论述，并在一定程度上定量的解释了其季节变化规律。

Summer feeding activities of zooplankton in Prydz Bay, Antarctica

Grazing of dominant zooplankton copepods (Calanoides acutus. and Metridia gerlachei), salps (Salpa thompsoni) and microzooplankton was determined during the austral summer of 1998/1999 at the seasonal ice zone of the Prydz Bay region. The objective was to measure the ingestion rates of zooplankton at the seasonal ice zone, so as to evaluate the importance of different groups of zooplankton in their grazing impact on phytoplankton standing stock and primary production. Grazing by copepods was low, and accounted for less than or equal to 1% of phytoplankton standing stocks and 3.8-12.5% of primary production for both species during this study, even the ingestion rates of individuals were at a high level compared with previous reports. S. thompsoni exhibited a relatively high grazing impact on primary production (72%) in the north of our investigation area. The highest grazing impact on phytoplankton was exerted by microzooplankton during this investigation, and accounted for 10-65% of the standing stock of phytoplankton and 34-100% of potential daily primary production. We concluded that microzooplankton was the dominant phytoplankton consumer in this study area. Salps also played an important role in control of phytoplankton where swarming occurred. The grazing of copepods had a relatively small effect on phytoplankton biomass development.

Toxicological evaluation of fucoidan extracted from Laminaria japonica in Wistar rats

Fucoidans, the sulfated polysacchrides extracted from brown algae, have been extensively studied for their diverse biological activities. However, there is no detailed report investigating the toxicity of fucoidan. In this study, the acute and subchronic (6 months) toxicity of varying levels of fucoidan extracted from Laminaria japonica was investigated in Wistar rats after oral administration. The results showed that no significant toxicological changes were observed when 300 mg/kg body weight per day fucoidan was administered to rats. But when the dose was increased to 900 and 2500 mg/kg body weight per day, the clotting time was significantly prolonged. Besides this, no other signs of toxicity were observed. Based on these results, it can be concluded that the no adverse effect level of fucoidan from L. japonica is 300 mg/kg body weight per day. (C) 2004 Elsevier Ltd. All rights reserved.

青藏高原高寒草甸植物群落物种组成和生物量沿环境梯度的变化

生物多样性与生态系统功能的关系及其机制是生态学领域的重大科学问题．人们越来越关注环境因子对多样性-生产力关系的影响．植物群落组成、物种丰富度、物种特征、生物量的分布结构和植物枯枝落叶对高寒草甸物种多样性和生产力有着重要的影响．因此，我们利用2001～2004年中国科学院海北生态系统定位站高寒草甸群落的实测资料，研究了不同环境梯度（土壤含水量和营养）下，植物群落生物量，物种丰富度及组成的变化．结果表明，植物群落物种组成的不同反应在生物量的分布上，以藏嵩草为优势种的藏嵩草沼泽化草甸群落总生物量（地上、地下）最高（13196．96±719．69g／m~2），次之是以杂类草和莎草科为主的小嵩草草甸（2869．58±147．52g／m~2），以禾本科和杂类草为主的矮嵩草草甸最低（2153．08±141．95g／m~2）．藏嵩草沼泽化草甸中，草本植物枯枝落叶显著高于小嵩草、矮嵩草草甸，土壤含水量对草本植物枯枝落叶有较大的影响．不同类型草甸群落中，地上生物量与土壤有机质、全氮和群落盖度之间均呈显著正相关（P〈0．05）；藏嵩草沼泽化草甸中，总生物量与物种丰富度呈负相关（rs=-0．907，P〈0．05）、地下生物量与土壤含水量呈正相关（rs=-0．900，P〈0．05）；而在小嵩草和矮嵩草草甸中它们之间均没有达到显著水平，说明不同类型高寒草甸群落生产力除受物种多样性、功能群内物种密度和均匀度的影响，同时也受物种本身特征和外部环境资源的影响．不同类型草甸群落生物量的分布与土壤含水量和土壤养分的变化相一致．