基于地理加权回归克里格模型的帽儿山地区森林碳储量空间分布

森林碳储量对于全球气候变化具有重要影响,以往的模型估算未考虑到模型残差的空间相关性和碳储量数据的非平稳性,影响模型的预测精度.本研究基于东北林业大学帽儿山实验林场的ETM+遥感影像数据和193块固定样地,利用地理加权克里格回归(GWRK)建立森林碳储量与遥感和地形因子的回归模型,同时对比最小二乘模型(OLS)、地理加权回归模型(GWR)的预测精度.结果表明: 对于帽儿山地区的森林碳储量估算,GWRK的平均绝对误差(MAE)、均方根误差(RMSE)低于OLS模型和GWR模型,GWRK模型的平均误差(ME)低于GWR模型,与OLS模型相近.GWRK模型的预测精度为83.2%,较OLS模型(73.7%)和GWR模型(77.3%)分别提高6%和10%,拟合精度明显提高,说明GWRK模型是森林碳储量估算的有效方法.利用GWRK模型预测的研究区森林碳储量平均值为70.31 t·hm^-2,在海拔较高的地区,森林碳储量值相对较高,说明海拔对其有较大影响.     

基于数字土壤制图技术的土壤有机碳储量估算

精准的土壤属性空间分布信息有助于提升土壤有机碳储量估算的精度。本研究以河南省济源市南山林场为研究区,以地形因子为预测因子,利用模糊C均值(FCM)聚类方法对土壤有机碳含量、土壤容重、土壤厚度和土壤砾石含量进行数字土壤预测制图,基于数字制图结果实现土壤有机碳密度预测制图和土壤有机碳储量估算。结果表明: 基于数字土壤制图方法得到的研究区土壤有机碳密度平均值为4.24 kg·m^-2,其预测图的平均误差(ME)为0.08 kg·m^-2,平均绝对误差(MAE)为2.80 kg·m^-2,均方根误差(RMSE)为5.03 kg·m^-2,与传统类型方法相比,预测结果的精度和稳定性更高,具有较高的可信度,最终估算得到研究区土壤有机碳储量为3.08×10⁸ kg。基于数字土壤制图技术仅采用少量土壤样点即可实现较高精度的土壤有机碳密度制图和储量估算,且能表征土壤有机碳密度空间分布特征。本研究为土壤有机碳储量估算提供了新途径,有助于提升土壤有机碳储量估算的精度和效率。     

中国湿地碳储量分布特征及其影响因素

湿地巨大的碳储存能力使其在稳定全球气候变化中占有重要地位,并对全球土壤碳储量做出重要贡献.本文在阐明湿地碳储量估算方法的基础上,分析我国主要湿地区碳储量并讨论气候、植被、土壤性质、土地利用等因素对湿地碳储量的影响.结果表明:东北湿地区和青藏高原湿地区是八大湿地区中碳储量最高的两大区域;泥炭湿地的高稳定性、低分解率及酚氧化酶的作用使其成为内陆地区碳储量最高的湿地类型;单一因素的双向干扰及多重因素的交互作用使得湿地碳储量的影响因素和作用机理更加复杂.注重多重因素的交互作用,并结合数据同化技术,有利于湿地碳储量及湿地生态系统价值预测与评估.     

山东省森林有机碳储量及其动态的研究

以各森林类型为统计单元 ,得出山东省现有森林有机碳储量为 43 .41Tg ,占全国的 1 .2 3 % ,是全国单位面积碳储量平均水平的 78.72 % (按土地面积计 ) ,各森林类型碳密度差异较大 ,介于 0 .40～ 49.46Mg·hm- 2 之间 ,密度大小与人为干扰程度有直接关系。并根据历年森林有机碳储量与碳密度变化情况 ,对未来 1 0年山东省的有机碳储量及碳密度变化情况进行了预测 ,在 3年后 ,森林有机碳储量接近全国平均水平 ,至 2 0 1 0年 ,全省森林有机碳储量可达 90 .31Tg ,比现在增长 1 .0 8倍     

基于MaxEnt模型的贵州省楠木潜在适生区预测

为揭示楠木(Phoebe zhennan)在贵州省潜在分布特征及其对环境因子的响应模式，该研究基于楠木在贵州省的地理分布点，运用最大熵模型(MaxEnt)与地理信息系统(ArcGIS)方法，结合气候、土壤及地形等30个环境因子，预测楠木在贵州省的潜在适生区，并分析了影响楠木生长的主要环境因子。结果表明：(1) MaxEnt模型AUC平均值为0.843,对贵州省楠木地理分布预测结果良好；楠木潜在适生区呈现以贵州省东北为重点区，从北到南、由东向西适生等级依次降低的趋势，高适生区主要在黔东北铜仁市、黔北遵义市中东部。(2)楠木在贵州省的潜在分布面积为80 013.47 km²,占全省总面积的45.4%,其中高适生区面积占全省总面积的17.4%。(3)等温性(Bio3)、最暖季度降水量(Bio18)、最湿月降水量(Bio13)、最干月降水量(Bio14)、最冷月最低温(Bio6)和温度季节性变动系数(Bio4)等是影响楠木在贵州省潜在分布的重要环境因子。该研究结果为贵州省楠木资源保护区划、种苗扩繁、造林推广与开发利用提供了科学依据。     

华南铅锌尾矿生态恢复的理论与实践

介绍了近年来有关华南地区5个铅锌尾矿生态恢复研究领域的主要研究成果。内容包括：铅锌尾矿的理化性质和影响植物定居的限制因子;尾矿酸化的预测与控制;尾矿的基质改良;尾矿自然定居植物的生态对策;重金属耐性植物的筛选与耐性机理;豆科植物在废弃地植被恢复中的作用;尾矿湿地系统的重建及其废水处理效率;土壤种子库在尾矿生态恢复中的作用;尾矿植被恢复的野外中试研究等。同时,也讨论了尾矿废弃地生态恢复的未来研究方向。     

Changes in carbon storages of Fagus forest ecosystems along an elevational gradient on Mt. Fanjingshan in Southwest China

森林生态系统碳库通常包括植被、土壤、凋落物与木质残体等几个组分。本研究旨在探讨中国一种重要的森林生态系统—水青冈林(Fagus L.)中这些碳库的沿海拔梯度格局变化及其驱动因子。在中国贵州省梵净山,沿海拔梯度(1095–1930 m)调查了9个水青冈林各碳库的碳储量。采用方差分解探讨了林龄、气候及其他因子对碳储量的影响,同时对梵净山与贵州和全球其他地区水青冈林的碳储量进行了比较。梵净山水青冈林生态系统碳储量在190.5–504.3 Mg C ha^–1之间,其主要组分包括植被碳库(33.7–73.9%)和土壤碳库(23.9–65.5%),而木质残体(0.05–3.1%)和凋落物(0.2–0.7%)对该生态系统碳储量的贡献不超过4%。随海拔升高,生态系统碳储量呈增加趋势,其中植被与木质残体碳库增加,而凋落物与土壤碳库无明显的变化趋势。对梵净山水青冈林,气候与林龄是其各组分碳储量海拔格局形成的主要原因;而对于全球水青冈林,林龄是其碳储量变化的主导因子。相比全球其他地区的水青冈林,贵州水青冈林具有较高的植被碳储量积累速率,这可能与贵州较高的降水量有关。本研究结果有助于理解中国水青冈林碳收支及其在区域碳循环中的可能作用,同时强调了林龄与气候对碳积累的重要性。     

青藏高原土壤碳储量及其影响因素研究进展

青藏高原是全球变化的敏感区,也是泛第三极地区气候变化的启动区。青藏高原土壤碳作为生态系统碳库的重要组成部分,对生态系统碳循环过程具有非常重要的作用。目前,对青藏高原土壤碳储量的估算仍存在很大的不确定性。为此,本文综述了近30年来关于青藏高原土壤碳储量研究,比较不同研究的土壤碳储量估算结果,以固有因子和变化因子两类影响因素作为切入点,分析了土壤碳储量时空分异规律。从估算模型和方法看,CENTURY和TEM模型综合考虑了影响土壤碳储量的多种机理过程,结果可信度高于EVI、NDVI模型以及插值估算法。青藏高原草地土壤表层(0～20 cm)有机碳储量约10 Pg C(1 Pg=10~(15)g)。高原冻土区土壤有机碳储量(0～200 cm)约16.5 Pg C,土壤无机碳储量(0～100 cm)约14 Pg C。青藏高原土壤碳储量沿东南向西北方向逐渐降低,而关于变化因子对青藏高原土壤碳储量的作用规律还没有一致的认识。此外,采样点选择、数据源选择、估算深度以及估算方法等影响了青藏高原土壤碳储量估算结果的精确性。未来青藏高原土壤碳储量研究应建立土壤碳储量估算标准来提高结果的可比性;同时增大采样区、采样量以及采样深度并保障采样周期的时间连贯性等,有效减少土壤碳储量估算不确定性。以期更好地理解和预测未来青藏高原生态系统对气候变化的响应。     

全球气候变化下贵州省青冈林的潜在生境动态

为了解贵州省青冈林在全球气候变化下的潜在分布特征,基于现状分布数据,结合当前气候数据和未来气候变化情景(RCP8.5情景,2070-2099年)构建Maxent潜在分布模型,预测贵州省青冈林的潜在分布变化。结果表明,最冷季均温(bio11)、最冷月最低温度(bio6)和年均降水量(bio12)为控制贵州省青冈林潜在生境的主导气候因子;RCP8.5情景下贵州省青冈林的潜在分布面积相较当前气候条件增加,中度适宜生境增加19 419 km2,高度适宜生境增加9 944 km2;中度适宜生境平均海拔较当前气候条件上升126 m,高度适宜生境平均上升85 m。总的来说,贵州省青冈林对全球气候变化的响应不十分敏感。     

典型喀斯特山区农业生物质能潜力估算——以贵州省为例

喀斯特山区生态环境脆弱,能源利用模式低值粗放,开展该区域的农业可利用生物质能潜力研究,对喀斯特山区农村能源建设和生态环境保护具有重要意义。以贵州省为例,在考虑土壤生态保留前提下,利用草谷比、土壤生态保留系数、收集系数、折标系数、副产物系数估算农村地区可利用农业生物质能资源总量。结果表明:(1) 2009—2015年间,贵州省年均可利用生物质能资源量达5191.50×10~4t标准煤,地均和人均农业生物质能资源量分别达到295 t标准煤/km~2和1.48 t标准煤/人,其中年均可能源化利用的达到1974.05×10~4t标准煤,占贵州省同期能源消费总量的21.84%。(2)贵州省生物质能储量结构比例分布不均,畜禽粪便资源利用潜力巨大,贡献值高达85%;其中,牛粪资源蕴藏量达年均3009.78×10~4t标准煤,贡献值达到68.39%,是贵州省最重要的农业生物质能资源。(3)从时序变化特征看,2009—2015年间贵州省生物质能资源量呈现U形结构,2011年达到最低值,这与2010年的西南大旱重要事件耦合。最后,针对贵州省农业生物质能现状,论文提出喀斯特山区应该合理布局秸秆电厂和秸秆固化成型燃料生产企业,提高畜禽的规模化养殖水平并加强农业生产防灾减灾工作,农村生活能源推广以沼气、节柴灶与节能秸秆气化炉高效利用相结合的能源利用结构等建议。     

锌对铅染毒新生大鼠成骨细胞增殖分化的影响

目的:探讨铅锌联合染毒对乳鼠颅骨成骨细胞增殖分化的影响。方法:分离并培养原代成骨细胞,加入不同浓度铅、锌培养48h,检测其对成骨细胞增殖的作用;用碱性磷酸酶试剂盒检测ALP活力。结果:在染铅48h后,当铅浓度≥10μmol/L时,细胞增殖功能下降(P<0.05);加锌干预48h后,铅+锌组细胞增殖功能均高于各自单独染铅组,其中铅(1μmol/L、10μmol/L)+锌(50μmol/L)组、铅(10)+锌(100)组与对照组间的差异具有统计学意义(P<0.05)。铅干预48h后,100μmol/L铅组的ALP活力显著下(P<0.05),给予锌干预的铅锌联合染毒组,各组ALP活力均有增加,其中铅(1μmol/L、10μmol/L)+锌(50μmol/L)组ALP活力均高于对照组,而铅(100μmol/L)+锌(50μmol/L)组ALP活力低于对照组,差异均有统计学意义(P<0.05)。结论:铅对成骨细胞有毒性作用,影响其增殖和分化功能;50μmol/L锌在一定程度上可以拮抗铅对成骨细胞增殖和分化功能的损伤,且对ALP活力的作用更显著,为铅中毒骨病的防治提供一定的科学依据。     

Characteristics of Phytogeochemistry in Copper Mine Area of Hongtou Shan,Liaoning Province

The contents of copper, zinc, lead nickel and cadmium for 322 samples of 44 species growing on copper mine area of Hongtou Shoo were determined. The results showed that the average contents of zinc, nickel, lead, cadmium in dry matter are 51.313 ppm, 1.536 ppm, 0.361 ppm and 0.058 ppm respectively. The variable range of zinc and cad- mium contents is larger, difference between minimum and maximum value is about 30–40 times. Zinc, lead and nickel contents in leaves of xylophyta in dry matter are mostly higher than in branches, but cadmium content of branches in dry matter is higher than leaves. The contents of lead and zinc in plants of minerelization areas are higher than that in non-minerelization areas. The results of correlative analysis showed that the linear regression between the metal contents in plants and soils are significant, for example, Lespedeza bicolor Thalictrum thumbergii, Arundinella hirta et al. It is important in phytogeochemical methods of prospecting for mineral. However, the correlative coefficients between the elements contents in leaves and branches of Quercus liaotungensis and in soils are not obvious. The correlative coefficient of nickel in plants and zinc, lead, cadmium and organic matter contents in soils are mostly negative value, without significant correlation. The results of the principal component analysis showed that the correlation of cadmium and zinc is significant among five elements in the plants. The contributive rate of first principal component is 33.94%, the positive target of the main target constitute is cadmium and zinc.     

Effects of sub-chronic low-level lead exposure on the homeostasis of copper and zinc in rat tissues

Information about the health risks or the subtle adverse health effects that might be associated with low-level lead exposure on micronutrient metabolism are scarce in the literature. The present work investigated the subtle adverse health effects of exposure to progressively low levels of lead on the metabolism of two micronutrients, copper and zinc in different tissues of the rat. Rats were exposed to 200, 300 and 400 ppm lead in their drinking water for 12 weeks. Lead, copper and zinc concentrations were determined in blood, liver, kidney, heart, spleen and brain of the animals. While the imbalance in zinc metabolism was characterized by a deposition of zinc in the kidney and to a lesser extent in the heart of the animals, imbalance in copper metabolism was characterized by a depletion of blood and splenic copper concentrations as well as renal and cardiac accumulation of copper. Hepatic and brain copper and zinc contents, together with blood zinc were not affected by the 12-week lead exposure. A linear relationship was observed between lead dose and lead accumulation in the spleen, whereas a non-linear relationship was observed between lead dose and lead accumulation in blood, liver, kidney and heart. Our findings indicate that exposure to progressively low-level lead concentrations results in imbalance in copper and zinc in the organism and this might be a factor in propensity toward behavioral disorders observed in lead exposure.     

Size dependent bioaccumulation of heavy metals by Mytilopsis sallei (Recluz) at Visakhapatnam harbour

Relationship between body size and bioaccumulation of copper, zinc, lead and cadmium in the fouling bivalve, M. sallei (Recluz) in Visakhapatnam harbour was studied. While concentration of copper, zinc and lead decrease with increasing size, no such relationship is observed for cadmium.     

Immunomodulation following zinc supplementation during chelation of lead in male rats

Influence of zinc supplementation (30 and 45 mg kg^–1, orally once for 5 days) during chelation of lead (0.3 mmol kg^–1, chelating agent, i.p., once for 5 days) on some selected variables of the immune system was investigated in male rats. Treatment with CaNa₂EDTA either alone or in combination with zinc (30 mg kg^–1) produced a significant recovery in lead induced alteration in primary antibody forming cells to T-dependent antigen and the delayed-type hypersensitivity response to bovine albumin. However, biologically significant recovery was observed only with zinc at a dose of 45 mg kg¹. It is assumed that zinc depletion during lead exposure and chelation treatment lead to harmful effects on cellular proliferation by inhibiting DNA synthesis and various enzymes during mitosis. The zinc supplementation fulfills this requirement during proliferation and clonal expansion of immunocompetent cells augmenting the immune system.     

Assessment of coronary flow reserve in nuclear cardiology

The coronary flow reserve is a quantitative parameter defined by the ratio maximal myocardial blood flow to rest myocardial blood flow, which allows to give functional information on the whole coronary arterial tree, integrating both epicardial arteries and microcirculatory. The coronary flow reserve is a powerful tool to guide therapy and to assess prognosis. Exploratory tools, initially limited to experimental invasive techniques, have evolved over the last 10 years, allowing to envisage its use in daily clinical practice. This article reviews the pathophysiology of the coronary flow reserve and the various invasive and non-invasive exploration tools available to practitioners, integrating them into clinical practice.     

The role of the cell wall in the mechanism of lead and zinc tolerance in Anthoxanthum odoratum L

The respiration rate and viability of cultured cells and protoplasts isolated from two clones of Anthoxanthum odoratum tolerant to both zinc and lead were unaffected by the presence of zinc. Although intact cells were largely unaffected by the presence of lead, protoplasts isolated from cultured cells were susceptible, showing a reduced respiration rate and a high mortality. In contrast cultured cells and protoplasts of non-tolerant clones of A. odoratum were susceptible to both zinc and lead. The results provide direct evidence that in A. odoratum the cell wall is part of the mechanism of tolerance to lead, but not to zinc.     

Microbiological leaching of zinc and lead ores of the Tekeli deposit

In certain regions of the West Tekeli lead-zinc ore deposti, the number of Thiobacillus ferrooxidans cells reaches 10(6) per 1 ml of ore water. Spontaneous bacterial leaching of sulphide ore is confirmed by an increase in the concentration of ferric iron and zinc in ore water. As a result of this leaching, up to 40 per cent of zinc and 60 per cent of lead have been leached from lead-zinc ore within 271-286 days. Bacterial leaching of lead intermediate products has shown that the maximum rate of galenite oxidation is reached at 50--65 degrees C and the content of Fe3+ in a solvent being above 20 g per litre. Microbiological leaching can be used for selective extraction of zinc and lead. Zinc dissolves directly in the leaching bacterial solution while lead remains in the precipitate and is then dissolved under the action of concentrated NaCl solutions.