An Experimental Test of Matrix Permeability and Corridor Use by an Endemic Understory Bird

Abstract:  Because of widespread habitat fragmentation, maintenance of landscape connectivity has become a major focus of conservation planning, but empirical tests of animal movement in fragmented landscapes remain scarce. We conducted a translocation experiment to test the relative permeability of three landscape elements (open habitat, shrubby secondary vegetation, and wooded corridors) to movement by the Chucao Tapaculo ( Scelorchilus rubecula ), a forest understory bird endemic to South American temperate rainforest. Forty-one radio-tagged subjects were translocated (individually) to three landscape treatments consisting of small release patches that were either entirely surrounded by open habitat (pasture), entirely surrounded by dense shrubs, or linked to other patches by wooded corridors that were otherwise surrounded by open matrix. The number of days subjects remained in release patches before dispersal (a measure of habitat resistance) was significantly longer for patches surrounded by open habitat than for patches adjoining corridors or surrounded by dense shrubs. These results indicate that open habitat significantly constrains Chucao dispersal, in accord with expectation, but dispersal occurs equally well through wooded corridors and shrub-dominated matrix. Thus, corridor protection or restoration and management of vegetation in the matrix (to encourage animal movement) may be equally feasible alternatives for maintaining connectivity.     

Modeling of oak pollen dispersal on the landscape level with a mesoscale atmospheric model

We present the extension and application of the mesoscale atmospheric meteorology model METRAS for dispersion of oak pollen. We incorporated functions for pollen emission, pollen viability and pollen deposition into METRAS and simulated pollen dispersal on a scale of up to 200 km. The basis of the simulations is a real landscape structure that includes topography, land use, and the location and size of oak stands. We simulated the oak pollen dispersion of one single oak stand with an estimated annual pollen production of 1 billion pollen grains/m² forest surface on two exemplary days of the flowering season in 2000. Depending on the meteorological situation of the simulated days, a pollen cloud with about 10 pollen/m³ may extend up to 30 km from the source. Downstream of the oak stand, approximately 1,000 pollen/m² deposited up to a distance of 25 km, and lower amounts of pollen deposited up to 100 km away. These values of pollen concentration and deposition lay within the range of published field studies. Overall, it is shown that mesoscale atmospheric models are applicable to simulate pollen dispersal on the landscape level.     

鼎湖山锥栗种子特征及其对动物取食格局的影响

通过对鼎湖山自然保护区锥栗种子特征的分析及进行种子取食实验，研究探讨了锥栗种子特征对动物取食格局的影响。结果表明，锥栗作为鼎湖山季风常绿阔叶林中的重要建群种之一，其更新困难的主要原因就在于种子扩散前后面临巨大的取食压力。动物对种子取食偏爱同种子大小呈现出一定的相关性，随着种子尺寸增加，取食率有线性增加的趋势。但是，锥栗应对动物取食并非完全被动的，它也发展了一些特有的生活史策略。锥栗种子的颜色与环境凋落物及土壤色相似，可以减少被取食者发现的机率。更重要的是，锥栗种子带刺的总苞有良好的保护作用。具总苞的种子取食的强度，显著低于无总苞的种子（P〈0．01）。     

Patch Size and Connectivity Thresholds for Butterfly Habitat Restoration

Abstract:  Recovery of endangered species in highly fragmented habitats often requires habitat restoration. Selection of restoration sites typically involves too many options and too much uncertainty to reach a decision based on existing reserve design methods. The Fender's blue butterfly (  Icaricia icarioides fenderi ) survives in small, isolated patches of remnant prairie in Oregon's Willamette Valley—a habitat for which <0.5% of the original remains. Recovery of this species will require considerable habitat restoration. We investigated the potential of biologically based rules of thumb and more complex models to serve as tools in making land acquisitions. Based on Fender's blue dispersal behavior and demography, we have estimated that restored patches should be <1 km from existing habitat and at least 2 ha. We compared these rules to the results of two modeling approaches: an incidence function model and a spatially explicit simulation of demography and dispersal behavior. Not surprisingly, the simple rules and complex models all conclude that large (>2 ha) connected (<1 km) patches have the highest restoration value. The dispersal model, however, suggests that small, connected patches have more restoration value than large, isolated patches, whereas the incidence function model suggests that size and connectivity are equally important. These differences stem from model assumptions. We used incidence functions to predict long-term, stochastic, steady-state conditions and dispersal simulations to predict short-term (25-year) colonization dynamics. To apply our results in the context of selecting restoration sites on the ground, we recommend selecting nearby sites when short-term colonization dynamics are expected to be an important aspect of a species' biology.     

Virtual Corridors for Conservation Management

Abstract:  Corridors are usually perceived as clearly visible, linear landscape elements embedded in a hostile environment that connect two or more larger blocks of habitat. Animal response to certain aspects of landscape heterogeneity, however, can channel their movements into specific routes that may appear similar to their surroundings. These routes can be described as "virtual corridors" (VCs). Here we contribute to the foundation of the concept of VCs and highlight their implications for conservation management. We used an individual-based model to analyze the formation of VCs in the case of hilltopping in butterflies—where males and virgin females ascend to hilltops and mate. We simulated butterfly movements in two different topographically heterogeneous landscapes. We analyzed the movement patterns with respect to one parameter, the intensity of response to topography. Virtual corridor structure depended on the behavioral parameter, landscape, and location of the source patch. Within a realistic range of the behavioral parameter and in a realistic landscape, VC structures may be complex and require individual-based models for their elucidation.     

超声波强化零价铁/过硫酸钾体系处理柠檬酸镍络合废水

以柠檬酸镍络合废水为目标废水,考察了超声波(US)强化零价铁(Fe~0)/过硫酸钾(PS)体系的初始pH、过硫酸钾用量(C_(PS))、超声波功率、零价铁与过硫酸钾质量比(m)、零价铁粒径(d_(Fe~0))对镍去除的影响.结果表明,在超声波功率为600 W,pH为3,过硫酸钾用量为0.45g·L~(-1),Fe~0∶PS(质量比)为0.8,零价铁粒径为75μm的条件下反应60 min时,镍的去除率可以达到100%.不同体系的对照实验和反应前后零价铁SEM、EDS分析结果表明,US/Fe~0/PS体系效果明显优于US/Fe~0、US/PS和Fe~0/PS体系,超声波对Fe~0/PS体系具有强化作用,能促进零价铁持续释放具有催化作用的Fe~(2+).最后,通过红外光谱和紫外光谱分析了柠檬酸镍破络机理.TOC变化规律表明,体系矿化速率低于体系中柠檬酸的降解速率,说明柠檬酸镍降解首先是一个快速破络过程,随后是破络后的中间产物进一步降解矿化.     

超声波预处理城市水厂剩余污泥的研究

利用超声波处理剩余污泥,通过离心作用模拟污水厂污泥脱水过程,以离心后含水率表征剩余污泥的脱水性能,最终确定最佳超声条件为:超声时间10 min,超声声能密度0.8 W/m L;另外分别研究了单独超声作用、单独絮凝剂作用以及超声-絮凝联合作用对剩余污泥脱水性能的影响。结果表明,单独超声处理或絮凝调理均可降低剩余污泥离心后含水率,超声波与絮凝剂共同作用能更好地提高剩余污泥的脱水性能,并对剩余污泥脱水性能改善的机理进行了理论分析。     

超声辐射法与絮凝剂联合作用对污泥脱水性的研究

文章使用PAM-C作为絮凝剂,研究超声波与絮凝剂联合作用对污泥脱水性能的影响,通过试验找到了其合理的调理顺序,并针对试验污泥确定了理想的试验参数,为污泥脱水处理找到一种行之有效的实用方法。     

Airborne myxomycete spores: detection using molecular techniques

Myxomycetes are organisms characterized by a life cycle that includes a fruiting body stage. Myxomycete fruiting bodies contain spores, and wind dispersal of the spores is considered important for this organism to colonize new areas. In this study, the presence of airborne myxomycetes and the temporal changes in the myxomycete composition of atmospheric particles (aerosols) were investigated with a polymerase chain reaction (PCR)-based method for Didymiaceae and Physaraceae. Twenty-one aerosol samples were collected on the roof of a three-story building located in Sapporo, Hokkaido Island, northern Japan. PCR analysis of DNA extracts from the aerosol samples indicated the presence of airborne myxomycetes in all the samples, except for the one collected during the snowfall season. Denaturing gradient gel electrophoresis (DGGE) analysis of the PCR products showed seasonally varying banding patterns. The detected DGGE bands were subjected to sequence analyses, and four out of nine obtained sequences were identical to those of fruiting body samples collected in Hokkaido Island. It appears that the difference in the fruiting period of each species was correlated with the seasonal changes in the myxomycete composition of the aerosols. Molecular evidence shows that newly formed spores are released and dispersed in the air, suggesting that wind-driven dispersal of spores is an important process in the life history of myxomycetes. This study is the first to detect airborne myxomycetes with the use of molecular ecological analyses and to characterize their seasonal distribution.     

低浓度氯苯废水在曝气生物填料塔中的降解

研究了曝气生物填料塔处理难生化降解化合物氯苯的特性,得出初始浓度为15mg/L的氯苯废水的适宜运行条件为:溶解氧约为5.5mg/L,水力停留时间约为5h,葡萄糖浓度为800mg/L,在此条件下单独用生物填料塔处理60h降解率可达16.80%。并考察了氯苯废水用超声预处理后生物降解与直接用生物降解比较,结果表明超声预处理可大大提高氯苯的可生物降解性,在30kHz+60kHz+100kHz的频率组合下超声预处理2h后再生物降解38h,氯苯的降解率可达70.12%。