甲氰菊酯在土壤中的降解及对蚯蚓的毒性效应研究

拟除虫菊酯作为全球第三大杀虫剂品种，在农业生产中广泛使用，同时也带来了一系列不利的环境影响。然而，目前有关拟除虫菊酯在土壤环境中的残留行为和风险评估报道较少。以典型拟除虫菊酯类杀虫剂甲氰菊酯(FEN)为研究对象，重点探究其在不同性质土壤中的降解行为以及对典型土壤生物蚯蚓的毒性效应。结果表明，甲氰菊酯在碱性土壤中的降解速度快于酸性土壤，同时在非灭菌土壤中的降解速度为灭菌土壤的4倍。因此，土壤酸碱度和微生物是影响FEN在土壤中降解快慢的主要因素。此外，在降解过程中检测到甲氰菊酯主要代谢物3-苯氧基苯甲酸(3-PBA)的生成。蚯蚓富集结果表明，FEN在蚯蚓体内的含量先升高后降低，最大生物富集因子为0.3。亚急性毒性结果表明，高剂量（5 mg?kg-1）甲氰菊酯暴露14 d后，蚯蚓体内蛋白质含量显著降低（P<0.05），细胞色素P450（CYP450）、羧酸酯酶（CarE）、谷胱甘肽-S-转移酶（GST）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性和丙二醛（MDA）含量均显著增加（P<0.05），同时存在剂量效应，证实土壤中残留的FEN对蚯蚓具有毒性效应。本文对甲氰菊酯在土壤环境中的降解行为研究以及生态毒性风险评估具有重要的指导意义。     

铝胁迫对山茶属植物光合特性的影响

以山茶属植物山茶花（Camellia japonica）品种花克瑞墨大牡丹以及茶（Camellia sinensis）的2个品种（白茶、乐茶）为材料，设置不同铝处理浓度，研究了铝对山茶属植物叶片光合作用特性的影响。结果表明，低浓度的铝处理促进了山茶属植物叶片叶绿素的合成和净光合速率的升高，高浓度的铝处理抑制了山茶属植物叶片叶绿素的合成，降低了净光合速率，胞间CO2浓度在不同铝浓度处理下变化不大，说明低浓度的铝能促进山茶属植物的光合作用，高浓度铝抑制了山茶属植物的光合作用。     

河朔荛花灌丛特性及其毒性的初步研究

对山西吉县蔡家川流域荛花灌丛的分布及其提取液的毒性进行了初步研究，结果表明，河朔荛花一般分布在阳坡立地上，半阳坡生长不良，阴坡基本无分布，其生物量与立地条件有明显的关系，其乙醇取液对3龄粘虫有一定的拒食作用，胃毒作用不明显，无触杀作用，对粘虫的生长具有明显的抑制作用。     

房屋建筑材用防腐剂的毒性试验

通过对十八种药剂配方(其中水溶性配方15种、油溶性配方3种)对木腐菌的毒性试验及对初筛后的配方进行流失后毒性试验,结果表明,水溶性配方中的铜铬砷即CCA_3、CCA_4、CCA_5,铜铬硼即CCB_5配方,以及油溶性配方中的P—B剂的毒性较大。     

Fertilizer-induced Changes in Rhizosphere Electrical Conductivity: Relation to Forest Tree Seedling Root System Growth and Function

Fertilization is standard practice in forest tree seedling nursery culture. Additionally, fertilization at outplanting has potential to facilitate nutrient uptake and reduce transplant shock. Fertilization, however, may dramatically alter rhizosphere chemical properties such as pH, ion availability, and electrical conductivity (EC). These changes may inhibit root system growth and function by reducing soil osmotic potential and creating specific ion toxicities. The risk of root damage associated with high EC levels appears to be dependent on species, age of root system, and soil moisture availability. Root inhibition in container nursery culture of conifers is likely to occur above 2.5 dS m⁻¹, though threshold EC levels for bareroot culture and field plantings are largely unavailable. Fertilization at outplanting has the added risk that drought conditions may prevent leaching of excess fertilizer salts, which can increase rhizosphere EC beyond safe levels and ultimately impair root uptake of water or nutrients. For fertilization programs to be successful, a critical threshold balance must be maintained between optimizing seedling nutrient availability in the rhizosphere, while minimizing potential for root damage. Future research is needed to identify optimal EC levels for a range of species across all stages of the reforestation process, from nursery culture through plantation establishment.     

白僵菌优良菌株的选育

本研究将所收集的28个菌株,用稀释单孢分离的方法,进行生长特征、生长速度、产孢量和室内外对松毛虫致病力的测定比较,以闽林2、闽林1、闽林3号菌株表现突出,为优良菌株。     

Growth and nutritional responses of bareroot Jeffrey pine on a Sierra Nevada surface mine to minisite applications of fertilizer and lime

The effects of two controlled release fertilizers, Forestcote 22-4-6 + Minors and Dry Site 21-6-2 + Minors, and also dolomitic lime, on growth and nutrition of bareroot Jeffrey pine (Pinus jeffreyi Grev. & Balf.) were investigated. Forestcote, which consists of loose prills, and Dry Site, consisting of prepackaged prills, were administered with two rates, while a single liming rate was used. An acidic Sierra Nevada surface mine provided the study site, and all amendments were applied at outplanting to the backfill of augered planting holes. Without impacting survival, both fertilizer formulations enhanced seedling growth, particularly at a 16 g rather than an 8 g application rate, although Forestcote was marginally more effective in this regard. In contrast, liming at a 27 g rate induced severe mortality and offset much of the growth gains resulting from fertilization. Improvements in N and P nutrition, as revealed by foliar analysis, probably accounted for much of the growth stimulation exhibited by fertilized seedlings, but reductions in the uptake of potentially phytotoxic trace elements such as Mn and Al and increases in base cation/metallic element ratios likely also contributed. The high application rate was generally preeminent in eliciting these nutritional responses. Liming induced little alteration of seedling nutrition. Impaired water relations may have caused the unfavorable responses to this treatment.     

杉木根际与非根际土壤酶活性比较

杉木根际与非根际土壤酶活性比较陈ｆ竣（中国林业科学研究院林业研究所北京１０００９１）李传涵（华中农业大学土化系武汉４３００７０）关键词杉木,根际土壤,土壤酶,杉木中毒由于林木生长的影响,使得林木根际土壤ｐＨ值、养分含量、微生物数目、生化活性等性质发生...