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101.
Throughfall and open field bulk precipitation were measured at three coniferous sites during 1995–2002 in the framework of
ICP Integrated Monitoring and at five coniferous sites during 1996–2002 in the framework of ICP Forests (Level II). The coniferous
canopies acted as a sink for nitrate and ammonium and as a source for base cations: Ca2+, Mg2+ and K+. The estimated share of SO4–S dry deposition from total deposition was 1.5–4 times higher for dormant period compared to growing period. During the study
period average annual throughfall and bulk deposition of SO4–S decreased significantly, 2.8 and 2.3 times, respectively.
Throughfall enrichment with base cations increased in the order Mg < Na < Ca < K. Using Na as a tracer ion, average dry deposition
and canopy leaching were calculated. Leaching was the dominant process for TF enrichment by potassium. Leaching of base cations
occurred during growing as well as dormant period.
The calculated internal flux of Ca2+ and Mg2+ varied in the range of 0.6–2.0 and 0.6–1.2 kg ha−1 per year in spruce and pine stands, respectively. The internal circulation of K+ was significantly higher (8.9–10.9 kg ha−1 per year) in spruce stands than in pine stands (2.7–4.4 kg ha−1 per year). 相似文献
102.
青岛市松针中多环芳烃污染状况研究 总被引:2,自引:1,他引:1
松针、苔藓类等植物可有效的监测环境空气中多环芳烃等有机污染物。为了解青岛市松针中多环芳烃的污染状况,本文使用索氏提取、氧化铝-硅胶净化柱净化、气相色谱-质谱(GC-MS)分析的方法,研究了青岛市6个不同区域的松针中多环芳烃的含量。该方法的提取净化效率在70.8%以上。在6个采样点中,1号采样点松针中的多环芳烃含量最低,平均为7.54ng/g(湿重含量),5号和6号采样点最高,分别为41.0ng/g和39.6ng/g。多环芳烃浓度季节变化规律为春季〉冬季〉夏季;松针中三、四环多环芳烃占总量的82%~90%,苯并(a)芘与多环芳烃总量具有较好的相关性。 相似文献
103.
Assessment of growth and stemwood quality of Scots pine on territory influenced by alkaline industrial dust 总被引:1,自引:0,他引:1
Long-term influence of alkaline dust (pH 12.3–12.7) pollution emitted over 40 years from a cement plant in Estonia was the
reason of alkalisation (pH 6.7–7.9) and high concentrations of K, Ca and Mg in the soil of affected territories. Although
dust emission has diminished during the last 10 years, the disbalances in nutrition substrate and their influence on the growth
of trees are notable up to now. The study of morphological and physical properties of 70–80-year-old Scots pine (Pinus sylvestris L.) crown, stems and stemwood from three different air pollution zones showed serious deviations in comparison with a relatively
healthy forest in an unpolluted area. The specimens from polluted trees, if compared to reference site, showed significantly
smaller height growth, radial increment and width of annual rings of sapwood. In heartwood wider annual rings were found in
polluted areas. In the period of heartwood formation the dust pollution level emitted from the plant was relatively modest
and cement dust, which contains elements necessary for mineral nutrition of trees, may have acted as fertiliser. The moisture
content in sapwood and heartwood, especially in the upper layers of stems, was lower in the polluted area than in reference
site trees. Regression analysis revealed a strong dependence between latewood percentage and sapwood or heartwood in stems
of Scots pine in all sample plots. 相似文献
104.
Decomposition studies were carried out at sites throughout Sweden, including the four Integrated Monitoring sites. Scots pine
needle litterbag weight loss measurements over 3 or 5 years were determined at 26 sites and repeated up to 27 times, depending
on the site. Humus layer respiration rates were determined for 20 sites in 1987–1989 and repeated in 2007–2008. Partial Least
Squares (PLS) regression was used to elucidate the relative importance of climatic and soil factors. Annual needle weight
losses decreased only slowly (20–10%) over 3–5 years for all northern (>60°N) sites but decreased sharply from 30 to 10% in
the third year in southern (<60°N) sites. Respiration rates of southern sites were less (40% on average) than those of northern
sites. Humus layer N was positively correlated to needle weight loss during the first and the second years, but negatively
correlated in the third year and to respiration rates. The results indicated that litter formed in southern Sweden became
more recalcitrant in later stages of decomposition compared to litter produced in northern Sweden. 相似文献
105.
利用黑龙江省牡丹江市海林市松毛虫发生情况与气象因子进行相关性分析,筛选出≥10℃积温正距平、夏季气温正距平和日最高气温≥30℃天数正距平、冬季气温正距平以及3-10月降水量负距平与松毛虫大发生有较好的相关性。其次,基于东北地区76个气象站,利用上述关键气象因子作为利于东北地区松毛虫大发生的气象条件进行分析。结果表明,1971-2010年40年东北地区年≥10℃积温、夏季和冬季气温均呈明显增加趋势,3-10月降水呈微弱的降低趋势,也就是说40年来东北地区气候变化趋向于利于松毛虫灾害发生。另外,对东北地区1971-2010年上述关键气象因子单因子利于松毛虫灾害发生的历史风险以及综合气象因子利于松毛虫灾害发生的历史风险进行分析,得出东北地区松毛虫灾害气象风险区划分布,结果表明吉林省中部、黑龙江大小兴安岭、牡丹江半山区的南部和西部松毛虫灾害气象风险约为10年二、三遇;辽宁大部,吉林省东南部、黑龙江松嫩平原和三江平原松毛虫灾害气象风险约为10年三至四遇。 相似文献
106.
探讨了改性松针(GXLsp)作为吸附剂对水体中铅离子的吸附性能,考察了吸附时间、溶液pH值、吸附剂用量、盐离子浓度、Pb(II)初始浓度及温度对改性松针吸附Pb(II)的影响。利用Langmuir和Freundlich等温线模型对实验数据进行非线性拟合分析,结果表明,Freundlich等温线模型能很好地描述松针对Pb(II)的吸附过程。热力学参数表明吸附是一个自发的吸热过程。改性松针对铅的吸附行为符合拟二级动力学方程,表明吸附过程是以化学吸附为主。在293K时松针对Pb(II)的饱和吸附量为318.3 mg/g,因此,GXLsp可作为一种高效低值生物质吸附剂以去除水体中重金属Pb(II)的污染。 相似文献
107.
N. A. Gazaliev 《Russian Journal of Ecology》2000,31(1):32-35
The abundance, structure, and distribution of oribatid communities in high-mountain pine forest biotopes of the Eastern Caucasus
are described in dependence on elevation above sea level. The oribatid fauna of high-mountain pine forests proved to be characterized
by high abundance, an assortment of dominants, and species richness. It was shown that, as the elevation increases, specific
dominants typical of particular altitudinal zones appear in communities, and changes in the mass species occur. These species
are stable in terms of their long-term dynamics, and zonal groups (communities) demonstrate a high species diversity. 相似文献
108.
109.
文章以河北省兴隆县雾灵山低山地区人工油松林为研究对象,采用植物群落样地调查法,对不同郁闭度的人工油松林样地灌木层和草本层群落的种类组成状况进行了观察和调查,并通过总优势度、Simpson指数、种间相遇概率等指标来探讨不同郁闭度下的油松林植物群落的物种多样性特点,以分析油松林郁闭度对其林下群落结构和物种丰富度的影响。结果表明在油松的郁闭作用下,林下灌木层植物密集,种类丰富,物种多样性高,而草本层植物稀疏,种类贫乏,物种多样性低;随着油松郁闭度的增加,灌木层物种多样性升高,草本层物种多样性有降低的趋势。 相似文献
110.
岷江上游油松造林密度对油松生长和群落结构的影响 总被引:19,自引:0,他引:19
调查了岷江上游 20a龄油松人工林样方 17个(20m×20m),测定了油松生长参数、林下植被的植物物种多样性和盖度,以分析油松生长和群落结构变化的密度效应.结果发现:油松高度生长随密度增大而增加,在密度 2 500~3 500hm-2时达最大,随后下降;胸径生长在 2 200~2 800hm-2时达到最大,随后下降.油松单位面积生物量由低及高,在 3 500~4 000hm-2达到最大,随后稍有下降;而个体平均生物量约在 2 500hm-2时最大.随着油松盖度的上升,灌木层盖度开始下降,林下散射光增加,导致草本层盖度上升,中等密度时 (2 500~3 500hm-2 )油松林乔灌草层次盖度配置较为合理;物种丰富度与油松密度呈显著负相关,但不同密度油松林的物种多样性指数变化无一定规律.因此,如果不以追求生物量最大化为单一目标,中等密度(2 500 ~3 500hm-2 )的油松林具有较好的群落结构配置、较高水平的物种多样性和种群更新能力,符合可持续林业发展的要求. 图 3参 19 相似文献