Lichen Conservation in Heavily Managed Boreal Forests

Lichens are an important component of the boreal forest, where they are long lived, tend to accumulate in older stands, and are a major food source for the threatened woodland caribou (Rangifer tarandus caribou). To be fully sustainable, silvicultural practices in the boreal forest must include the conservation of ecological integrity. Dominant forest management practices, however, have short‐term negative effects on lichen diversity, particularly the application of herbicides. To better understand the long‐term effects of forest management, we examined lichen regeneration in 35 mixed black spruce (Picea mariana) and jack pine (Pinus banksiana) forest stands across northern Ontario to determine recovery following logging and postharvest silvicultural practices. Our forest stands were 25–40 years old and had undergone 3 common sivilcultural treatments that included harvested and planted; harvested, planted, and treated with N‐[phosphonomethyl] glycine (glyphosate); and harvested, planted, and treated with 2,4‐dichlorophenoxyacetic acid (2,4‐D). Forest stands with herbicide treatments had lower lichen biomass and higher beta and gamma diversity than planted stands that were not treated chemically or control stands. In northwestern Ontario, planted stands that were not treated chemically had significantly greater (p < 0.05) alpha diversity than stands treated with herbicides or control stands. Our results show that common silvicultural practices do not emulate natural disturbances caused by wildfires in the boreal forest for the lichen community. We suggest a reduction in the amount of chemical application be considered in areas where lichen biomass is likely to be high and where the recovery of woodland caribou is an objective. Conservación de Líquenes en Bosques Boreales Manejados Intensivamente     

Hotspots of Epiphytic Lichen Diversity in Two Young Managed Forests

Understanding within-stand variation in diversity of epiphytes will provide an improved basis for producing timber while conserving biological diversity. Two 80-ha, 50–year–old managed stands of conifers were surveyed to locate 0.4 ha putative "diversity" plots, the areas appearing most diverse in lichen epiphytes. These plots were generally located in areas made heterogeneous by canopy gaps, wolf trees (trees with large-diameter lower branches), and old-growth remnant trees. "Matrix" plots, in contrast, were chosen at random from the remaining, more homogenous forest. Diversity plots hosted from 25% to 40% more epiphytic lichen species than matrix plots in both stands. The strongest within-stand gradients in species composition were correlated with percentage of plot occupied by gaps and wolf trees. Percentage of the plot in gaps was correlated with species richness (r = 0.79). In the more structurally diverse stand, diversity and abundance of nitrogen-fixing "cyanolichens" were correlated with percentage of the plot occupied by gaps (0.5 < r < 0.9), and alectorioid lichens were correlated with percentage of the plot occupied by old-growth remnant trees (0.5 < r < 0.6). In the stand with more homogenous structure, percentage of the plot under gaps was correlated with regionally common species that were otherwise absent or sparse in the matrix. Protecting gaps, hardwoods, wolf trees, and old-growth remnant trees during thinning or other partial cutting is likely to promote the majority of epiphytic macrolichens in young conifer forests. Because these features are easily recognized on aerial photos and on the ground by land managers, it is practical to manage for forest structures that would promote lichen diversity.     

The Existence and Removal of Evaporable 137Cs-Containing Compound(S) From the Extract of Lichen Cetraria Islandica

The aim of the work described here was to investigate the existence of evaporable ¹³⁷Cscontaining compound(s) in lichen and to suggest a possible way of dealing with a phenomenon during lichen exploitation. A sample of lichen, Cetraria islandica, was submitted to aqueous extraction and the extract was monitored to be ¹³⁷Cs-radioactive. It was heated according to the experimental schedule and the resulting vapour passed over a layer of activated charcoal. By measuring the decrease in the radioactivity content of the lichen extract after heating and the radioactivity of the adsorbent it was found that a significant amount of the extracted ¹³⁷Cs could be evaporated and bound to the charcoal adsorbent (40.6%). If not captured, this radiocaesium may lead to air pollution, especially of immediate breathing space.     

固氮菌与氮配施对生菜及油菜产量和品质的影响

采用盆栽试验研究了固氮菌(M)与氮(N)配施对生菜、油菜产量和品质的影响.结果表明:施加固氮菌(M2)后,生菜、油菜的鲜重和干重较之不加固氮菌(M1)有显著增加趋势,生菜、油菜的Vc含量分别提高4.2%~18.6%、17.6%~35.0%,还原糖含量分别提高17.6%~35.0%、6.7%~41.3%,硝酸盐含量分别降低40.5%~57.2%、22.8%~40.8%.在所有处理中,处理M2N3的两种蔬菜产量最高,品质最好.研究可为固氮菌肥的合理有效施用、氮肥的优化配比及叶菜类蔬菜高产优质的生物调控提供理论依据.图1表3参13     

乡镇企业可持续发展与小城镇建设

通过对乡镇企业的经济效益、环境效益和社会效益以及小城镇发展的优越性分析可知，乡镇企业不宜在农村发展，应该在小城镇中发展。     

恩诺沙星与Cu复合污染对白菜和西红柿根及芽伸长的抑制作用

抗生素恩诺沙星和重金属Cu是当今我国土壤中较常见的污染物。本研究考察了恩诺沙星与Cu复合污染对砖红壤中白菜和西红柿种子的根及芽伸长的影响,以评估恩诺沙星和Cu复合污染潜在的生态风险。结果表明,加入不同浓度的Cu时,土壤中的恩诺沙星浓度与2种作物的根伸长和芽伸长的抑制率均显著相关(P0.05);白菜的敏感性均大于西红柿;白菜和西红柿的根伸长对复合污染的生态毒性的敏感性均较芽伸长更高;与单一恩诺沙星胁迫相比,在恩诺沙星与Cu(100 mg·kg~(-1))或Cu(300 mg·kg~(-1))复合污染下,二者对白菜和西红柿的根及芽伸长抑制效应均表现为协同作用。试验结果在揭示恩诺沙星与Cu复合污染的生态毒性效应的同时,也为重金属和抗生素复合污染的生态风险评价提供科学依据。     

甲胺磷和乙草胺对产甲烷菌种群数量及其活性的影响

采用厌氧培养箱、气相色谱技术和MPN计数法,研究了甲胺磷和乙草胺在4种浓度(0 1、0 2、0 5和1 0mg·L-1)下对水稻田土壤产甲烷菌种群数量及其活性的影响。加甲胺磷后7d内刺激产甲烷菌种群的生长,数量增加0.2～44.1倍,每管的产甲烷量增加0.8～2.1倍,且刺激作用随药剂浓度的增加而增强;加乙草胺后7d内,产甲烷菌的生长受到抑制,数量下降了50%～99%,每管的产甲烷量显著减少,且抑制作用随药剂浓度的增加而增强。随着加药时间的延长,甲胺磷和乙草胺逐渐降解,产甲烷菌数量又恢复至原有水平。     

费氏中华根瘤菌ntrBC基因突变株的构建及其特性

从费氏中华根瘤菌(Sinorhizobium fredii)HN01基因文库的重组质粒pGXHN300上获得ntrB、ntrC基因完整序列.通过自杀质粒pK18mob同源单交换的方法,分别获得了HN01菌株的ntrB和ntrC基因的突变株GXHNB、GXHNC.功能检测证明GXHNB、GXHNC能以硝酸盐为唯一氮源进行正常生长,但不能以铵源作为唯一氮源进行正常生长.图4表2参15     

Bacterial degradation of monocrotophos and phyto- and cyto-toxicological evaluation of metabolites

The bacterium Serratia marsescens strain JAS16 was isolated from agricultural soil which had prior exposure to monocrotophos for three years. The strain JAS16 tolerated up to 1200 mg L^–1 monocrotophos and degraded the insecticide (1000 mg L^–1) at a degradation rate constant of 136 d^?1 (DT₅₀ = 3.7 d). In soil, the degradation rate constant was 105 d^?1 (DT₅₀ = 4.8 d). A schematic pathway is being proposed from the degraded products derived from gas chromatography--mass spectrometry (GC-MS). The phytotoxicity of degradation products to Vigna radiata, Vigna unguiculata, and Macrotyloma uniflorum and the genotoxicity to Allium cepa roots were found to be low. A cost-effective powder-based formulation was achieved with the isolate. The isolate remained viable during the storage and also multiplied with a higher colony forming units (CFU) load g^–1 for over a period of seven weeks of storage.     

氮磷营养盐因子对缘管浒苔生长、叶绿素荧光特性和氮磷富集的影响

为探讨大型海藻缘管浒苔(Ulva linza)对氮、磷加富的生理响应及其机制,分析了氮、磷浓度变化对藻体相对生长速率(Rr.g),氮、磷富集,叶绿素(Chl)含量,类胡萝卜素(Car)含量,色素比值(Chl a/Chl b、Chl/Car)以及叶绿素荧光参数的影响.结果表明,在30μmol·L-1P浓度不变条件下,随着N浓度的增加,藻体P含量持续降低,而其Rr、g、N含量、Chl含量、Car含量、色素比值(Chl a/Chl b、Chl/Car)和叶绿素荧光参数均逐渐上升,N3处理(500μmol· L-1 N)缘管浒苔Rr.g和叶绿素荧光参数均达到最大值,N4处理(1 000 μmol·L-1)缘管浒苔Chl含量、Car含量和Chl a/Chl b比值均达到最大值.在500 μmol·L-1N浓度不变条件下,依次增加P浓度,缘管浒苔Rr,g没有显著差异,N含量没有显著变化,而P含量则呈明显上升趋势,其他指标变化幅度小.综上所述,与P相比,N的变化对缘管浒苔生长、光合色素和光合作用的影响更明显,在N浓度为500 μmol·L-1、P浓度为30 μmol ·L-1、N/P比值为16.67条件下,藻体生长最佳.当水体富营养化加剧时,缘管浒苔富集氮、磷的能力持续上升.     

有机无机肥配施比例对蔬菜产量和品质及土壤重金属含量的影响

关于蔬菜施有机肥和它与无机肥的合理配施比例,对蔬菜的产量和品质有重要影响,对土壤有机质和重金属含量也有影响。为控制施禽畜粪类有机肥对蔬菜的负面影响,探讨蔬菜的合理施用量和有机/无机肥配施比例,在不同质地的土壤上进行田间试验。结果表明,(1)施过量禽畜粪类有机肥对试验蔬菜产量和品质都会产生不良影响,小白菜(Brassica chinensis)和茄子(Eggplant)施禽畜粪超过22500kg/hm2、马铃薯(Solanum tuberosum L.)超过24000kg/hm2时,其产量不再增加,成活率下降,维生素C含量下降,多个试验均表现出有机肥用量增加而小白菜硝酸盐随之增加的典型特征;同时不论土壤的质地轻重,蔬菜重金属Pb有随禽畜粪用量增加而提高的趋势;在质地较轻的土壤上,蔬菜重金属Cd、As有随禽畜粪用量增加而提高的趋势;小白菜施禽畜粪肥超过7500kg/hm2、茄子和冬种马铃薯施禽畜粪肥超过75000kg/hm2,收获后土壤重金属含量高于对照和施无机肥的总Cr和As。(2)蔬菜单独施用有机肥的合适施用量,小白菜在较粘重的土壤上可施到22500kg/hm2,但有机肥与无机肥配合施用时有机肥用量可减量;茄子合适施用量应在22500kg/hm2左右;冬种马铃薯合适施用量应在24000kg/hm2左右。(3)蔬菜的有机/无机肥合理配比,小白菜、茄子、和冬种马铃薯施肥的有机氮与无机氮之比均为0.25∶1至0.5∶1时其产量和品质水平较佳。     

Problems and prospectus of utilization of sewage and industrial wastewaters in agriculture

The basic objective of this study was to compile the available information on the composition of sewage and industrial wastewaters in India and their effect on soil–plant health upon their use in agricultural fields. The composition of sewage water is quite variable depending upon the contributing source, mode of collection, and treatment provided. The composition of sewage water varied from site to site which was in accordance with the type of industries present in that area. Continuous use of sewage and industrial wastewater irrigation recorded improvement in water retention, hydraulic conductivity, organic C and build-up of available N, P, K, micronutrient status, and soil microbial count. The electrical conductivity although increased due to sewage irrigation, it was within the tolerance limit to cause any soil salinity hazard. The toxic metals like Cd, Cr, Pb, and Ni were found to be accumulated in soil and plant due to long-term use of sewage and industrial wastewater irrigation. The concentration of these metals was higher in leafy vegetables than in grain crops. This warrants the potential hazard to soil–plant health suggesting necessity of their safe use after pretreatment as a cheap potential alternative source of plant nutrients in agriculture.     

Influence of temperature and pH on the effects of zinc and copper on proteolytic activities of the intestinal mucosa of planktivorous and benthophagous fishes and their potential preys

Influences of temperature (0 and 20°C) and pH (3.0, 5.0, and 7.4) on the effect of zinc (Zn) and copper (Cu) on proteolytic activities of intestinal mucosa in planktivorous (blue bream, bleak), bentophagous (bream, roach) fishes and their potential preys (pond snail Limnaea stagnalis, planorbid Planorbarius purpura, dreissena Dreissena polymorpha, midge larvae Chironomus sp., water flea Daphnia longispina and total zooplankton) are revealed in this article. Cu decreases the caseinolytic and hemoglobinolytic activities in both fish and their preys more than Zn at temperature 20°C and pH 7.4. Low temperature intensifies the negative effect of the metals on the protease activity in fish (in the case of Zn 5–10 times, in the case of Cu 5–30 times). In fish prey species, the negative effect of the metals on the proteinase activity may be more significant. The influence of pH on Zn and Cu effects is less pronounced than that of low temperature. Maximum reduction of enzyme activities is observed for the combined action of low temperature and pH as well as of the studied metals.     

方位及冠层对厚朴果实和种子形态变异的影响

为从方位及冠层的角度探讨光照对厚朴(Magnolia officinalis)果实和种子形态变异的影响,分别从植株的不同方位和冠层采集果实、种子,并测定其形态指标。结果表明,方位对厚朴果实和种子的形态变异影响显著,不同方位厚朴果实和种子的表型性状表现为南方位和东方位优于西方位,南、东和西3个方位均优于北方位;冠层对厚朴果实和种子的形态变异影响显著,不同冠层果实和种子性状表现为中冠层优于上冠层,上冠层优于下冠层;方位和冠层对厚朴果实和种子多项形态指标的协同作用不显著。与果实相比,种子的表型性状更稳定。     

氯虫苯甲酰胺在甘蓝和土壤中的残留及消解动态

参照《农药残留试验准则》,采用田间试验方法,研究了济南和杭州两年两地的氯虫苯甲酰胺在甘蓝和土壤中的消解动态和最终残留。结果表明,氯虫苯甲酰胺最终残留在甘蓝、土壤中的质量分数分别是〈0.297 mg.kg-1,〈0.097 mg.kg-1;在甘蓝、土壤中的降解均符合一级动力学方程,降解半衰期分别为7.2～8.9 d和6.9～10.7 d;统计分析表明,两地区甘蓝中的残留消解行为无显著性差异,土壤中的残留消解行为差异性显著,土壤性质的不同是影响消解过程的主要因素。文章为制定该农药在甘蓝上最大残留限量标准和合理使用准则以及风险评估提供了科学依据。     

Assessment of solid waste and dumpsite leachate and topsoil

Dumpsite leachate contains different hazardous substances, some of which threaten the environment. In this study, municipal solid waste, dumpsite leachate and topsoil from seven different dumpsites in Lagos and Ibadan, Nigeria were analysed using standard methods. The parameters analysed in the composite leachate samples collected are pH, solids, alkalinity, chloride, nitrate, sulfate, phosphate, biochemical oxygen demand, chemical oxygen demand turbidity, heavy metals (e.g. Zn, Pb, Co, Ni, Cd) and some persistent organic pollutants (e.g. polyaromatic hydrocarbons [PAHs] and polychlorinated biphenyls [PCBs]). Total organic carbon, heavy metals (e.g. Zn, Pb, Co, Ni, Cd) and organic pollutants (e.g. PAHs, PCBs) were analysed in the dumpsite topsoil and the control samples. The samples for heavy metal determination were digested using concentrated nitric acid and the digestate was analysed using atomic absorption spectrometry, whereas organic pollutants were extracted using cold extraction and quantified by gas chromatography-mass spectrometry (GC-MS). The study revealed that dumpsites in Ibadan have ～90% domestic and 10% industrial waste, whereas the figures for Lagos are 80% and 20%, respectively. In the leachate samples, concentrations of PAHs and PCBs ranged from 0.85 to 1.47 mg/L and 0.01 to 0.08 mg/L, respectively; the values were 0.94–2.79 mg/kg and 10.0–412 μg/kg in the topsoil. If not properly managed, dumpsite leachate can seep into groundwater and surface water via run-off, and can have adverse effects on human health and the entire ecosystem.     

代森锰锌及其代谢产物在荔枝与土壤中的残留动态

采用田间试验方法,研究了代森锰锌及其代谢物乙撑硫脲(ETU)在荔枝及土壤中的残留动态。结果表明,质量分数为80%的代森锰锌可湿粉剂在荔枝树上喷施后,主要残留在荔枝果皮中,且消解速度较快,其中母体消解半衰期为4. 02~5. 14d; ETU消解半衰期为2. 52~3. 24d;代森锰锌及ETU在土壤中消解较快,半衰期分别为5. 63~9. 88d和4. 95~14. 2d。施药1 600mg·L-1,使用4次,末次施药距收获间隔10、20和30d,荔枝果肉中代森锰锌残留量均小于1mg·kg-1,代谢产物ETU均小于0. 02mg·kg-1。该药为易消解农药(t1 /2 <30d),按推荐剂量使用是安全的。