Climate changes in the past century and radial increment of pine in the Southern Ural steppe

Changes in the main climatic factors (air temperature and total precipitation) and their effect on the radial increment of Scots pine (Pinus sylvestris L.) over the period from 1933 to 2002 were studied in an insular pine forest growing in the steppe zone of the Southern Urals. Evidence for a significant increase in the amount of precipitation and air temperature in the second half of this period was obtained. Functions of response of radial increment indices to climatic parameters were analyzed. Relative contributions of air temperature and precipitation to variation in the radial increment of pine in different time intervals proved to differ in relation to climate changes during the past century.     

松毛虫遗传多样性研究中AFLP反应体系的建立

以油松毛虫为材料,对T4 DNA连接酶不同用量、预扩增中的Mg~(2+)浓度、dNTP浓度、引物浓度以及选择性扩增巾的预扩增产物稀释倍数、Mg2~(2+) 浓度、dNTP浓度、引物浓度和Taq酶浓度进行了比较分析.最终建立了适合松毛虫的AFLP反应体系.用优化的AFLP反应体系,以油松毛虫、赤松毛虫和马尾松毛虫为材料筛选引物,从81对引物组合中筛选出10对多态性高的引物组合.图9参17     

Combining a generic process-based productivity model and a statistical classification method to predict the presence and absence of tree species in the Pacific Northwest,U.S.A.

Although long-lived tree species experience considerable environmental variation over their life spans, their geographical distributions reflect sensitivity mainly to mean monthly climatic conditions. We introduce an approach that incorporates a physiologically based growth model to illustrate how a half-dozen tree species differ in their responses to monthly variation in four climatic-related variables: water availability, deviations from an optimum temperature, atmospheric humidity deficits, and the frequency of frost. Rather than use climatic data directly to correlate with a species’ distribution, we assess the relative constraints of each of the four variables as they affect predicted monthly photosynthesis for Douglas-fir, the most widely distributed species in the region. We apply an automated regression-tree analysis to create a suite of rules, which differentially rank the relative importance of the four climatic modifiers for each species, and provide a basis for predicting a species’ presence or absence on 3737 uniformly distributed U.S. Forest Services’ Forest Inventory and Analysis (FIA) field survey plots. Results of this generalized rule-based approach were encouraging, with weighted accuracy, which combines the correct prediction of both presence and absence on FIA survey plots, averaging 87%. A wider sampling of climatic conditions throughout the full range of a species’ distribution should improve the basis for creating rules and the possibility of predicting future shifts in the geographic distribution of species.     

The Dynamics of Species Composition and Abundance of Wasps from the Families Pompilidae, Sphecidae, and Vespidae (Hymenoptera: Aculeata) in Successional Pine Biogeocenoses of the Berezinskii Biosphere Reserve

The data on the dynamics of population size and species composition of wasps from the families Pompilidae, Sphecidae, and Vespidae were obtained in the course of long-term studies carried out in successional pine forests of the Berezinskii Biosphere Reserve. The abundance and species diversity of wasps were significantly higher in a polewood forest (40 years) than in a young forest (20 years) and mature moss forest (70 years). In an overgrown ride in the moss pine forest, the composition of dominant wasp species remained relatively stable during the seven-year period of observations, although the number of species and their abundance varied significantly from year to year, depending on the weather.     

An Approach for Evaluating the Effectiveness of Various Ozone Air Quality Standards for Protecting Trees

We demonstrate an approach for evaluating the level of protection attained using a variety of forms and levels of past, current, and proposed Air Quality Standards (AQSs). The U.S. Clean Air Act requires the establishment of ambient air quality standards to protect health and public welfare. However, determination of attainment of these standards is based on ambient pollutant concentrations rather than prevention of adverse effects. To determine if a given AQS protected against adverse effects on vegetation, hourly ozone concentrations were adjusted to create exposure levels that “just attain” a given standard. These exposures were used in combination with a physiologically-based tree growth model to account for the interactions of climate and ozone. In the evaluation, we used ozone concentrations from two 6-year time periods from the San Bernardino Mountains in California. There were clear differences in the level of vegetation protection achieved with the various AQSs. Based on modeled plant growth, the most effective standards were the California 8-hr average maximum of 70 ppb and a seasonal, cumulative, concentration-weighted index (SUM06), which if attained, resulted in annual growth reductions of 1% or less. Least effective was the 1-hr maximum of 120 ppb which resulted in a 7% annual reduction. We conclude that combining climate, exposure scenarios, and a process-based plant growth simulator was a useful approach for evaluating effectiveness of current or proposed air quality standards, or evaluating the form and/or level of a standard based on preventing adverse growth effects.     

Gradient analysis of the chrogenetic structure of lowland and highland scotch pine populations

Gradients of genetic distances (GGDs) between 26 adjacent cenopopulations of Scotch pine (Pinus sylvestris L.) along the transects through the distinct landscape-ecotopic isolation borders were analyzed graphically. The results made it possible to reveal and quantitatively estimate gradients and borders of gene-pool structural patterns in populations of this species in the central part of Northern Eurasia. In lowland areas, the most distinct borders were found between pine populations growing on dry lands and bogs (Pineta sphagnosa) in the forest zone of the Transural region, as well as between the Arakaragaiskii and Amankaragaiskii island pine forests in the steppe zone (Northern Turgai). In highland areas (the Urals and the Carpathians), the greatest GGDs were observed between low-mountain (about 600 m above sea level) and middle-mountain (850–900 m) populations. Analysis of GGDs is a promising gene-geographic method for determining population borders and studying the chorogenetic structure of species.     

Long term changes in atmospheric N and S throughfall deposition and effects on soil solution chemistry in a Scots pine forest in the Netherlands

In a Scots pine forest the throughfall deposition and the chemical composition of the soil solution was monitored since 1984. (Inter)national legislation measures led to a reduction of the deposition of nitrogen and sulphur. The deposition of sulphur has decreased by approximately 65%. The total mineral-nitrogen deposition has decreased by ca. 25%, which is mainly due to a reduction in ammonium-N deposition (−40%), since nitrate-N deposition has increased (+50%). The nitrogen concentration in the upper mineral soil solution at 10 cm depth has decreased, leading to an improved nutritional balance, which may result in improved tree vitality. In the drainage water at 90 cm depth the fluxes of NO₃⁻ and SO₄²⁻ have decreased, resulting in a reduced leeching of accompanying base cations, thus preserving nutrients in the ecosystem. It may take still several years, however, before this will meet the prerequisite of a sustainable ecosystem.     

模拟氮沉降对重庆缙云山马尾松林土壤呼吸和酶活性的季节性影响

土壤酶参与土壤碳氮转化,同时土壤碳氮状况又是土壤酶活性的基础,而大气氮沉降通过影响土壤酶活性进而影响土壤CO_2释放.通过野外模拟试验,探讨不同氮沉降量对马尾松土壤呼吸和酶活性的影响,探索该区域马尾松土壤呼吸(Rs)与土壤温度(T)、土壤湿度(W)、Ure(脲酶)、Ive(转化酶)、CAT(过氧化氢酶)及ACP(酸性磷酸酶)的关系,为深入研究氮沉降对马尾松林森林生态系统的影响提供参考.2014年5月~2015年7月在缙云山马尾松林设置3个氮添加水平和一个无氮添加的对照处理:低氮[N_5,20 g·(m~2·a)~(-1)],中氮[N_(10),40 g·(m~2·a)~(-1)]、高氮[N_(15),60 g·(m~2·a)~(-1)]和对照[N0,0g·(m~2·a)~(-1)],每个处理量分4次,在每个季度开始各施1次,每个处理各9次重复,采用ACE(automated soil CO_2exchange station,UK)自动土壤呼吸监测系统分别对土壤呼吸、土壤温度和土壤湿度进行分析测定.结果表明:1土壤酶和土壤呼吸均具有明显的季节变化规律,各处理土壤呼吸均表现为夏季最高,其次是春季和秋季,最低为冬季,而各处理土壤酶活性则无一致的变化规律.2总体而言,氮沉降对土壤呼吸和酶活性均有抑制作用,且抑制程度随氮浓度增加而加强,但冬季氮沉降对马尾松林土壤呼吸有促进作用,春、夏、秋这3个季节氮沉降对Ure、Ive、CAT及ACP有抑制作用,而冬季氮沉降对4种土壤酶活性影响则存在差异.3逐步回归表明,无氮和低氮处理时,T、Ure和Ive对Rs的贡献较大,且随着T、Ure和Ive的增加,Rs也急剧增加;中氮处理时,T、Ure和CAT对Rs的贡献较大,Rs随着T、Ure和Ive的增加而增加;高氮处理时,Rs随着Ure的增加而降低,随着CAT和W的增加而增加.     

缙云山马尾松林和柑橘林土壤微生物PLFA沿海拔梯度的变化

土壤微生物群落是土壤生态系统的重要组成部分,对环境变化敏感.本文运用磷脂脂肪酸法(PLFA)研究缙云山马尾松林和柑橘林土壤微生物群落结构沿海拔梯度的变化特征.结果表明,从6个海拔土壤中共检测到48种PLFA,其中i16:0、10Me17:0、10Me18:0 TBSA在6个海拔中含量均最高,且柑橘林土壤PLFA种类和含量明显高于马尾松林.随着海拔升高马尾松林土壤微生物种类和含量逐渐增加,柑橘林则逐渐降低,各海拔间细菌、真菌、放线菌、革兰氏阴性菌(G~-)及革兰氏阳性菌(G~+)含量差异显著.土壤微生物群落多样性研究结果表明,马尾松林低海拔丰富度指数(R),多样性指数(H')、均匀度指数(J)均显著高于高海拔,而柑橘林R在低海拔最高,H'、J则在高海拔最高.不同海拔土壤细菌、放线菌、G~-及G~+与土壤酶和环境因子之间存在相关性,细菌、放线菌、G~-及G~+与脲酶(Ure)、转化酶(Ive)、过氧化氢酶(CAT)、林分类型均呈极显著正相关,真菌与Ure、Ive、CAT呈显著正相关;而细菌、真菌、放线菌、G~-及G~+与海拔呈极显著或显著负相关.Ure、Ive、CAT、林分及海拔是影响土壤微生物PLFA变化的重要因子.     

重庆南山马尾松衰亡与土壤铝活化的关系

研究了重庆南山马尾松衰亡与铝中毒的关系.发现南山土壤中活性铝含量相当高,而活性钙含量很低,轻灾区和重灾区的Al/Ca比都已超过伤害植物的阈值.试验结果表明,铝活化是土壤严重酸化的后果.溶液培养试验结果表明,铝对马尾松幼苗生长有明显毒害作用,且毒性最大的形态是Al~(3+),铝中毒是南山酸雨危害马尾松的主要原因.