Vegetation and soil recovery in wilderness campsites closed to visitor use

Recreational use of wilderness results in impacts to vegetation and soil in trails and campsites. Traditionally, campsite impact studies have compared campsites receiving various levels of use with unused control areas. Field studies in Sequoia National Park, California, indicate that the degree of impact to vegetation and soils also varies within campsites. The central areas of campsites, where trampling is concentrated, show lower plant species diversity, differences in relative species cover, more highly compacted soils, and lower soil nutrient concentrations than do peripheral, moderately trampled, and untrampled areas within the same campsite. Three years after closure to visitor use, the central areas show less increase in mean foliar plant cover, and soils remain more highly compacted than in previously moderately trampled areas of the same sites. Changes in relative species cover over time are used to assess both resiliency to trampling and species composition recovery within campsites closed to visitor use.     

Evaluation of anthropogenic atmospheric inputs on US national park ecosystems

It is estimated that more than half the threats to national park resources originate outside park boundaries, and most threats are attributable to degradation of air and water quality. Atmospheric contaminants are the principal source of external threats to national park ecosystems. This article examines the potential impact to national park resources by anthropic atmospheric inputs and summarizes present research methods and results regarding impacts. Air quality monitoring currently receives much more emphasis and support than effects research. Present research on effects focuses on vegetation impact, biomonitoring, and acid rain. This research and that of other investigators suggest that the most likely impacts will not be direct cause-effect situations, but indirect, incremental, and possibly synergistic effects on the interactions of ecosystem components. Conceptually, such alteration of interactions can be measured through long-term observation of biogeochemical cycles, energy transfer, and community structure and function. But traditional Park Service research has not emphasized the ecosystem and especially ecosystem processes and component interactions. Most research on effects, then, must begin with baseline data acquisition. A research program to mitigate present national data base deficiencies would require a fundamental change in present research priorities, administration, and funding.     

Are bison exotic in the Wrangell-St. Elias National Park and Preserve?

The effect of past distributions of animal populations now extinct in an area from unknown causes is considered relative to their status as exotic or native in national parks. The example is the bison (Bisonbison) on the Copper and Chitina river drainages in Alaska in the USA which was introduced prior to establishment of Wrangell-St. Elias National Park and Preserve. The fossil record suggests that bison were present as recently as 500 years ago in Alaska. The policy of the US National Park Service to maintain natural ecosystems and restrict or eliminate exotic species raises the issue of whether this species should be treated as exotic or native.     

MODERNIZATION OF NATIONAL WEATHER SERVICE RIVER FORECASTING TECHNIQUES1

The National Weather Service is nearing the conclusion of a five year period of transition from index type catchment modelling to the use of conceptual hydrologic models. The decision to make this technological change was based on an extensive research project in which various catchment models were tested in a wide variety of basins and their strong and weak points ascertained. This project is described. Some of the problems involved in the changeover, which are discussed, are practical parameter optimization methods, computer requirements for the more complex technology, data requirements, fitting of the catchment model to major river systems, training of personnel and staffing problems.     

Implementation of two new resource management information systems in Australia

This paper describes the development and implementation ofPREPLAN, A Pristine Environment Planning Language and Simulator, for two conservation areas in Australia, Kosciusko National Park (New South Wales) and Tutanning Nature Reserve (Western Australia).PREPLAN was derived from the North American gradient modeling systems and theForest Planning Language and Simulator (FORPLAN), but includes unique characteristics not previously available.PREPLAN includes an integrated resource management data base, modules for predicting site-specific vegetation, fuels, animals, fire behavior, and fire effects, and an English language instruction set.PREPLAN was developed specifically to provide available information and understanding of ecosystems to managers in a readily accessible and usable form, and to provide the motivation to conduct additional required research projects. An evaluation of the system's advantages and limitations is presented, and the way the utilization of such systems is improving natural area decision making throughout Australia is discussed.     

臭氧微气泡处理酸性大红3R废水特性研究

微气泡技术与臭氧废水处理相结合,有助于促进臭氧气液传质、改善臭氧氧化效果并提高臭氧利用率.本研究采用臭氧微气泡氧化处理酸性大红3R废水,考察了臭氧微气泡的气液传质特性以及对酸性大红3R氧化降解特性,并与臭氧传统气泡进行比较.结果表明,微气泡能够强化臭氧气液传质,相同条件下其臭氧传质系数为传统气泡的3.6倍;同时微气泡系统的臭氧分解系数为传统气泡系统的6.2倍,有利于·OH产生.臭氧微气泡可显著提高酸性大红3R氧化降解速率和矿化效率,其TOC去除率可达78.0%,约为传统气泡的2倍.臭氧微气泡处理酸性大红3R过程中的臭氧利用率显著高于传统气泡:微气泡系统平均臭氧利用率为97.8%;传统气泡系统平均臭氧利用率为69.3%.臭氧微气泡通过促进·OH产生提高臭氧氧化能力,其对降解中间产物的氧化速率更快,其中对小分子有机酸的矿化能力约为传统气泡的1.6倍.     

微球负载双核锰配合物作为新型非均相CWPO催化剂对活性蓝P-3R的脱色应用

以微胶囊技术为负载手段,将一种具有高效催化氧化活性的双核锰配合物Mn L负载到了乙基纤维素微球中,采用电感耦合等离子发射光谱仪(ICP)、紫外可见(UV-VIS)光谱扫描、扫描电镜(SEM)、透射电镜(TEM)等表征测试手段对该微球负载催化剂进行了相关的形态结构表征,发现催化剂Mn L在乙基纤维素微球基质内分散良好,并保持了其原结构的完整性.将制备的该Mn L负载微球用于催化活性蓝P-3R溶液模拟染料废水的氧化脱色反应,表现出了很好的催化氧化性能.催化氧化脱色实验发现,其不仅可以催化活性蓝P-3R溶液至完全氧化脱色,并具备一定的可循环利用性,在经过4次循环使用后仍可催化活性蓝P-3R溶液达到70%以上的氧化脱色率,可以作为一种新型的非均相CWPO催化剂用于染料废水的脱色处理.     

FePMo12催化电化学反应降解染料废水的研究

采用IR和XRD等方法对自制磷钼酸铁(FePMo12)杂多酸进行表征,表明杂多阴离子具有Keggin结构.将FePMo12负载于修饰后的4分子筛(4A)上制备FePMo12/APTES-4A催化剂填充于电化学反应器中,考察电化学氧化体系对酸性大红3R染料废水的脱色效果.结果表明,FePMo12/APTES-4A催化剂对酸性大红3R模拟废水具有良好的催化效果,当活性组分负载量为3%时,在pH为4,槽电压为22 V,曝气量为0.08 m3·h-1,极板间距为3.0 cm反应条件下,90 min后脱色率达到75.3%,COD和TOC去除率分别达到65.4%和46.0%.加入支持电解质Na2SO4和NaCl后,NaCl对电催化降解染料废水有促进作用,而Na2SO4的加入使得废水的脱色效率降低.采用可见-紫外光谱对反应过程中间产物进行分析,表明染料分子中的共轭体系已基本被破坏.     

县级系统开展全民环境教育探讨

叙述环境教育的产生及发展,介绍目前环境保护及环境教育还存在的问题,讨论了开展环境教育的必要性及有利条件,及在县级开展环境教育的基本作法。     

一种新型防结冰阻火一体化呼吸阀的应用

针对北方寒冷地区石油储罐呼吸阀和阻火器,特别容易发生结冰阻塞不能正常呼吸而使得储罐冬季安全运行存在重大隐患,介绍了一种新型防结冰阻火一体化呼吸阀,并与普通呼吸阀对比分析了两种呼吸阀的优缺点,证明该种新型呼吸阀从设备本质上解决了普通呼吸阀的冬季结冰堵塞等安全隐患,具有推广价值。