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“五一”节日期间,应朋友之邀,到八卦山一游。怡人仙道八卦山。“八卦山”因其地形地貌形似“八卦图”而得其名。置身“八卦山”。一股浓烈的绿的芬芳扑面、迎怀。绿意葱茏。气息清新。给你强烈的感觉就是一个字——绿。她绿得彻底,绿得妖娆,绿得芬芳,绿得灿然,绿得自在,绿得饱满。绿得甘冽。看。那绿色的树林,让人充满想像,那象征着生命的绿色。绝对是最舒服的颜色。那芙丽的树林不是用来漫步游荡的,而是用来让人抬头现望、欣赏的,欣赏树叶与阳光的完芙结合。阳光在叶的缝隙里轻轻地射进来,像一位绅士,永远都是那么礼貌和有风度。阳光照得叶子闪闪发光。就像没有瑕疵的玉石。晶莹、玲珑。它们拥有淡淡的百合花的味道,清新脱俗．用自己的肢体去实现生命的价值。 相似文献
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小院的东北角，堆放了大量的建筑垃圾，形同小丘。天长日久，便生出许多植物来。以草本为多，间夹低矮的木本。几棵南瓜和香瓜，于石头缝里绽放生机，在荒芜中展示生命的精彩。这些植物怎么来到了此处？问这样的问题，对于出身农村的我来讲，是很愚蠢的。飞籽成林。这种子当然是飞来的。一是随风飘落，二是飞鸟撒下了粪便，其中便有没消化的植物种子。仲秋时节，天气凉爽，我喜欢到与之毗邻的栅栏边锻炼身体。秋虫唧唧，阳光生彩，一个蓬蓬勃勃的野生世界，充满了无限的生机。每每看到有如工棚里建筑工人一样随遇而安的南瓜花和香瓜花，我的心里就特别安宁。为什么呢？我不甚清楚，但我天天来，天天锻炼，天天看它们，内心里越发恬静。那些大大小小的花朵，每天都在发生微妙的变化。从绽放到盛开，那是花朵一生一世的辉煌。 相似文献
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在关乎共同利益及未来面前，人类似乎正在摈弃政治、宗教、信仰等偏见，渐渐在趋向大同。本刊在去年9月号上。对美国前副总统戈尔写的《无法忽视的真相》进行了解读。那本书以无可辩驳的事实，客观地展示了全球性的生态危机，指出：人类自救只有十年期。超过了这个期限、许多危机便无法逆转。无独有偶。在去年9月。新华出版社出版了姜春云主编的专著《偿还生态欠债——人与自然和谐探索》。此书展示的是中国的生态危机。与戈尔不同的是。此书不只列举了现象和危害，更重要的是对生态危机的深层原因进行了尖锐剖析。并借鉴国内外众多专家学者最新研究的成果，对解决生态危机提出了应对之策。该书内容翔实丰富。数据准确权威，方法科学实用。结论严谨缜密。这是一束穿越历史的理性之光，让几十年来沉迷在巨大发展的我们，看到了自身的疏忽以及由此欠下的生态巨债，看到了这种疏忽背后的种种因果链条，看到了走出困境走向希望的唯一之路。作为前奏，本刊新年1月号已先刊发了姜春云同志为该书写的序言，本篇以解读的方式对全书的内容进行隆重推介。限于篇幅，所作的解读也只能蜻蜒点水。但作为一个推介者，本刊希望所有关注中国未来发展的人，能够挤时间坐下来读读原著，让这束穿越历史的理性之光也穿越你的心灵．引导你真切地洞察我们的过去．现在及将来。 相似文献
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百年期盼。百年梦圆。2008年8月8日。伴随中华民族伟大复兴的脚步。中国人的奥运梦想终于实现了。北京这座六朝古都。800多年皇城的中轴线上，故宫展现着沧桑的姿态。“鸟巢”呈现着现代的容颜。前者是历史老人的大度与超然，后者如时代天骄的自信与稳健。此刻一同站在了2008年北京奥运的历史时刻前。迎接着五洲之风四海之澜。今天，本刊记者兵分两路。分别在故宫、天安门附近、“鸟巢”附近纪录行人那些真真切切的感受。实实在在的故事。那些充满生活气息的期待与渴盼。骄傲与荣耀。带给我们的是不寻常的感动和美好。 相似文献
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缅甸：近期，柚木的需求量依然很大，而且等级较高的柚木原木的供应量有所减少。结果导致市场中等级较低的柚木销量增长。由于价格较低及使用范围广泛，4等锯材原木是最受欢迎的等级。一些较高等级的锯材和单板可以从4等锯材原木中获得。价格随柚木等级不同而稳步的下降。价格取决于可用森林的面积、可用原木的数量和等级及汇率等因素。 相似文献
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皆伐方式对小兴安岭低质林土壤呼吸的影响 总被引：2，自引：1，他引：1
针对小兴安岭低质林分,采用不同的皆伐方式,利用LI-8100碳通量自动监测系统在春、夏、秋、冬4个季节对低质林分土壤呼吸进行观测,运用统计分析的方法,分析皆伐方式对土壤呼吸的影响和不同皆伐方式的土壤呼吸产生差异的原因.结果显示:试验区土壤呼吸夏季最大,冬季最低.春季和秋季因土壤温度和湿度差异不大使土壤呼吸相差较小;对于水平带同一条皆伐带,土壤呼吸并无显著性差异,并且不同的带宽对土壤呼吸的影响也不显著;垂直带随海拔升高土壤呼吸呈现波动性,总体趋势随海拔升高土壤呼吸逐渐降低,但是差距较小;水平带、垂直带和林窗的年土壤呼吸量分别为1.184,1.426,1.179 kgCO2·m-a-1,垂直带最高,水平带次之,林窗最低.影响垂直带土壤呼吸的关键因素是土壤温度,林窗则是土壤湿度,而水平带土壤温度和湿度的条件则介于垂直带和林窗之间.这说明在不同的皆伐方式条件下,影响土壤呼吸的关键因素并不完全相同. 相似文献
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祁连山土壤呼吸的时空变异及其与影响因子的关系 总被引：1，自引：0，他引：1
采用美国Li—cor公司生产的L16400-09土壤呼吸室连接到L16400便携式光合作用测量系统,对祁连山不同植被类型土壤呼吸速率进行了连续1年在生长季的野外测定,并通过多元回归手段对其影响因子进行了分析。结果表明：1）2003年生长季祁连山不同植被类型土壤呼吸速率的季节动态均为一单峰曲线,最大值出现在7月份;2）不同植被类型之间的土壤呼吸及其影响因子都存有一定程度的空间变异,且随着季节的变化,表现出一定规律性;其变异系数分别为：土壤呼吸速率在21．4％-72．18％之间,温度在12．00％-38．67％之间,土壤水分在32．17％．201．34％之间,地上生物量在72％左右;3）CO2释放速率、气温、土壤含水量和生物量之间的关系分析表明约有81％的土壤呼吸量变化是由气温、土壤水分和生物量共同决定的。 相似文献
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Comparison of field methods for measuring soil respiration: a static alkali absorption method and two dynamic closed chamber methods 总被引：19，自引：0，他引：19
The objectives of the present study were to compare the static alkali absorption (AA) and dynamic closed chamber (DC) methods for measuring soil respiration, and to evaluate the effects of methodological differences on estimating annual mean soil respiration rate in a natural forest. For the AA method, we used Kirita’s method [Jpn. J. Ecol. 21 (1971) 119] using an alkali-soaked sponge disc that covers nearly the same area as that covered by a chamber. For the DC method, we used both the LI-6200 system (DC-62 method) and the newer LI-6400 system (DC-64 method) (LI-COR, Lincoln, NE, USA). Comparative measurements were conducted on five occasions during the study period (November 1998–October 1999) at a Quercus serrata forest in Japan. Daily mean soil respiration rates obtained by the AA, DC-62 and DC-64 methods for a 24 h period were in the ranges 205–578, 147–629 and 165–734 mg CO2 m−2 h−1, respectively. The daily mean soil respiration rates obtained by the AA method were 79–128% of those obtained by the DC-64 method. When the daily mean soil respiration rate obtained by the DC-64 method was below 300 mg CO2 m−2 h−1, the daily mean soil respiration rate obtained by the AA method was an average of 26% higher than that obtained by the DC-64 method. When the daily mean soil respiration rate obtained by the DC-64 method was above 300 mg CO2 m−2 h−1, the daily mean soil respiration rate obtained by the AA method was an average of 19% lower than that obtained by the DC-64 method. However, at the present site, there was a little difference between the two methods as for estimating annual mean soil respiration rate, and therefore the AA method improved by Kirita [Jpn. J. Ecol. 21 (1971) 119] is suggested to be a useful method for estimating annual mean soil respiration in the forest. The daily mean soil respiration rates obtained by the DC-62 method were systematically 10–24% lower (an average of 15% lower) than those obtained with the DC-64 method, and the annual mean rate was lower than that estimated by the AA method. 相似文献
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Heterotrophic respiration strongly influences carbon cycles at the ecosystem and global scales. We used an automated chamber system to measure the heterotrophic respiration of coarse woody debris (CWD) and leaf litter in a secondary broadleaved forest in southern Kyoto Prefecture. This system, which targeted only organic matter, could detect heterotrophic respiration responses to changes in environmental factors, especially rainfall events. The temporal trends and responses of respiration to environmental factors differed dramatically between CWD and leaf litter. CWD respiration showed a clear diurnal change corresponding to changes in CWD temperature and a clear decrease during rainfall events. Leaf litter respiration did not change clearly but increased at the beginning of rain events and returned to pre-rain rates when soil water content declined. The temporal patterns of the residuals between the observed respiration and baseline respiration, developed from the temperature?Cresponse curves under pre-rain conditions, differed between CWD and leaf litter respiration. The typical trend in CWD respiration response to rainfall events was a clear decrease and then gradual increase in the residuals after the event. The response of leaf litter respiration to wetting was an increase in the residuals during rainfall events and then a gradual decrease during drying. The difference in the responses of these respirations to wetting and drying processes are likely caused by differences in the physical characteristics of the CWD and the leaf litter layer. Measurements targeting only organic matter using an automated chamber system could detect the responses of heterotrophic respiration to environmental factors. 相似文献
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以贡嘎山国家级自然保护区中峨眉冷杉(Abies fabri)林为研究对象,采用LI-6400-09便携式土壤呼吸室对其土壤呼吸速率进行了连续定位观测。结果表明:(1)峨眉冷杉成熟林和中龄林的土壤呼吸速率和土壤温度在各个月份存在差异;(2)两种林分的土壤呼吸速率具有明显的季节变化特征,表现为夏季>秋季>春季>冬季;成熟林的月平均土壤呼吸速率在0.82μmol·s-1·m-2～5.88μmol·s-1·m-2之间,季节变差系数为50.6%,中龄林的月平均土壤呼吸速率在0.52μmol·s-1·m-2～3.52μmol·s-1·m-2之间,季节变差系数为48.5%;(3)两种林分的土壤呼吸速率季节变化与土壤5 cm温度呈显著性正相关;(4)峨眉冷杉成熟林和中龄林土壤CO_2释放率的Q10值分别为3.2和2.6,峨眉冷杉成熟林土壤呼吸对温度的敏感性指数要大于中龄林。 相似文献
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The impacts of elevated atmospheric CO2 concentrations (500 μmol·mol−1 and 700 μmol·mol−1) on total soil respiration and the contribution of root respiration ofPinus koraiensis seedlings were investigated from May to October in 2003 at the Research Station of Changbai Mountain Forest Ecosystems, Chinese
Academy of Sciences, Jilin Province, China. After four growing seasons in top-open chambers exposed to elevated CO2, the total soil respiration and roots respiration ofPinus koraiensis seedlings were measured by a Li-6400-09 soil CO2 flux chamber. Three PVC cylinders in each chamber were inserted about 30 cm into the soil instantaneously to terminate the
supply of current photosynthates from the tree canopy to roots for separating the root respiration from total soil respiration.
Soil respirations both inside and outside of the cylinders were measured on June 16, August 20 and October 8, respectively.
The results indicated that: there was a marked diurnal change in air temperature and soil temperature at depth of 5 cm on
June 16, the maximum of soil temperature at depth of 5 cm lagged behind that of air temperature, no differences in temperature
between treatments were found (P>0.05). The total soil respiration and soil respiration with roots severed showed strong diurnal and seasonal patterns. There
was marked difference in total soil respiration and soil respiration with roots severed between treatments (P<0.01); Mean total soil respiration and contribution of root under different treatments were 3.26, 4.78 and 1.47 μmol·m−2·s−1, 11.5%, 43.1% and 27.9% on June 16, August 20 and October 8, respectively.
Foundation item: This study was supported by the Knowledge Innovation Project of the Chinese Academy of Sciences (KZCX1-SW-01) and the National
Natural Science Foundation of China (30070158).
Biography: LIU Ying (1976-), female, Ph. D. Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China.
Responsible editor: Song Funan 相似文献
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黄土高原地区柠条人工林土壤呼吸 总被引：4，自引：0，他引：4
2005—2008年用红外气体分析法测定柠条人工林地的土壤呼吸。结果表明:柠条林地土壤呼吸具有明显的日变化特征,最大值出现在14:00左右,最低值出现在凌晨;柠条林地3—12月的土壤呼吸总量为814.9～1224.7gC·m-2,表现出明显的季节变化和年际变化;土壤呼吸与土壤温度呈显著指数正相关,方程的决定系数R2为0.31～0.67,由拟合的指数方程系数计算出柠条林2005,2006,2007和2008年的Q10值分别为2.02,1.70,1.76和1.75,生长季和非生长季的Q10值分别为0.64和2.11;2005和2006年土壤呼吸速率与土壤水分呈极显著线性相关(P0.01),方程的决定系数R2在0.30左右,而2007和2008年则不显著(P0.05);生长季(5—9月)土壤水分起主要作用,可以解释土壤呼吸季节变化的55%,非生长季土壤温度起主要作用,可以解释土壤呼吸季节变化的37%;4个双因子模型可以解释土壤呼吸季节变化的51%～83%。 相似文献
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In this study, the stand level root respiration was estimated for two monoculture plantations: Acacia crassicarpa and Eucalyptus urophylla, based on in situ measurement of specific root respiration using simplified root chamber method. The respiration rates of fine roots (<5 mm) were significantly higher than those of coarse roots (>5 mm) for both A. crassicarpa and E. urophylla species. The root respiration of A. crassicarpa showed a clear seasonal pattern with a higher value in the wet season. For E. urophylla, the seasonal pattern was observed for fine roots but not for coarse roots. After determining the biomass of fine roots and coarse roots and their specific rates of respiration at different time points, root respiration at the stand level (Ra) was estimated using a direct up-scaling model. We found that the Ra accounted for 14% and 19% of total soil respiration (Rs) for A. crassicarpa and E. urophylla, respectively. The fine (RTf) and coarse (RTc) root respiration at the stand level accounted for about 47% and 53% of the Ra for A. crassicarpa, and accounted for 58% and 42% for E. urophylla. This suggests that coarse root respiration cannot be ignored when estimating the root respiration at the stand level. Our results showed that the Q10 values were more accurate in representing the temperature dependence when the confounding effect of soil moisture was considered. This study introduces an alternative approach to estimate stand level root respiration, but its reliability is largely dependent on the accuracy of root biomass quantification. 相似文献
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利用LI-COR-8100土壤CO2通量自动测量系统测定了湖北赤壁幕布山区采伐毛竹林土壤表面CO2通量及5 cm深度的土壤温度、湿度,研究了采伐对毛竹林土壤呼吸的影响,并用壕沟法区分各组分呼吸。结果表明:采伐显著增加了毛竹林的土壤温度,但对土壤湿度无显著影响;采伐能增加土壤呼吸、凋落物呼吸与矿质呼吸,但降低了根系呼吸;土壤总呼吸及组分呼吸与土壤温度呈指数相关(R2=32.63%84.50%),与土壤湿度呈线性相关(R2=40.60%93.50%),运用土壤温度、湿度复合模型能提高预测土壤呼吸的准确性(R2=41.40%96.20%)。采伐毛竹林土壤呼吸的增加主要因为采伐后土壤温度升高所致。 相似文献