Recommendations for rural abandoned mine program (RAMP) in Iowa,USA

In the last three years, twelve orphan coal surface mines in Iowa, USA, have been reclaimed under the Federal Rural Abandoned Mine Program (RAMP) by smoothing highly acid spoils, covering the spoils with a thin dirt layer and planting a cover crop. Ten years ago a test plot was designed with a wedge of loess over acid spoils. Subsequent observation suggests that on the new RAMP sites, acidified throughflow and discharge of shallow soil moisture and groundwater will gradually kill the vegetation in the lower valleys and erosion will proceed upvalley as a migrating knickpoint. The problem might be eliminated by directing the acidified throughflow beneath the cover material, in sand underdrains or tile lines in the main drainages. The discharge could either be diluted in a nearby creek, if adequate flow is available, or neutralised in a basin paved with limestone rip-rap. Vegetation which was found to be especially well adapted to thin cover sites includes native prairie grasses, crownvetch and cattails. Sphagnum mosses may also offer some possibilities for such locations. A RAMP reclamation site should be designed as an experimental area to test these methods and determine their cost. These recommendations may also be applicable in other mining areas.     

Patterns of use of space in a guild of territorial reef fishes

There exists on Heron Reef, at the southern end of the Great Barrier Reef, an 8-species guild of ecologically very similar, territorial, herbivorous reef fishes. All individuals of these species maintain territories on rubble substrata throughout juvenile and adult life. Territories are defended from all other guild members. Three rubble patches, each containing residents of 3 guild species: Pomacentrus apicalis, P. wardi, and Abudafduf lachrymatus, have been monitored for 12 to 18 months. This paper examines the patterns of use of space as shown by the antecedent and subsequent histories of sites chosen by 43 new colonists, and sites vacated through the loss of 34 residents on the rubble patches. In addition, variation through time is examined in the total amount of space held in territories on each rubble patch. The 3 species show similar preferences for space as colonists, although adult and juvenile colonists behave differently. Numbers of colonists detected on rubble patches are not proportional to the resident populations of the 3 species. Residents of the 3 species are equal in their abilities to enter spaces vacated through mortality, although they differ slightly in methods used to enter sites. They do not respond preferentially to sites previously occupied by any particular species. P. wardi shows a higher rate of mortality than the other species, and residents of this species are more often dislodged by new colonists. The total amount of space held on any rubble patch did not vary during the year from September, 1972 to October, 1973. The data are interpreted as supporting the hypothesis that the 3 species do not differ in their requirements for space on rubble patches, and that they are in competition for a short supply of such space. Differences exist in their strategies for obtaining and holding such space. These differences are important for explaining the continued presence of P. wardi on rubble patches. P. apicalis and a. lachrymatus are both specialists in holding territories on the upper reef slope. No differences have been detected in their requirements or competitive abilities. P. wardi is a fugitive species on the upper reef slope, coexisting because it maintains a refuge from competition by occupying some un-preferred sites off rubble patches.     

Mating system of the hermaphroditic coral-reef fish,Serranus baldwini

Summary The lantern bass, Serranus baldwini, is a small hermaphroditic serranid found adjacent to coral reefs throughout the Caribbean. Data from gonad inspection, spawning behavior, and gamete release from individuals all confirm that populations consist of simultaneous hermaphrodites and males. This gender pattern appears to be sequential, with larger males derived from smaller hermaphrodites. The social system is haremic, with the male defending an area containing 1–7 hermaphrodites. The social system and gender pattern are similar to those of the eastern Pacific serranid, Serranus fasciatus. Males obtain disproportionately high mating success by being nearly the sole mates of hermaphrodites within their harems. Hermaphrodites obtain very low levels of mating success through male function. This pattern may result from female choice by hermaphrodites, mate sequestering tactics by males, or both. The serranids that change gender from hermaphrodite to male appear to have a higher environmental potential for polygyny than other simultaneous hermaphrodites in this family. Factors that may maintain male function in hermaphroditic S. baldwini are outlined, but none currently provides clear evidence for why this species has not evolved to protogyny.     

Physiological ecology of four Polysiphonia species (Rhodophyta,Ceramiales)

Photosynthesis and respiration of 4 species of the marine red algal genus Polysiphonia were evaluated under a variety of light, temperature and salinity conditions. The manometric results were compared with the local distribution and abundance of each species. The species can be separated into two distinct categories based on their overall distribution and temperature optima: (1) cold water plants [P. lanosa (L.) Tandy and P. elongata (Hudson) Sprengel], with peak photosynthesis at 21° to 24°C, but with active photosynthesis as low as 5°C; (2) plants with warm-water affinities [P. nigrescens (Hudson) Greville and P. subtilissima Montagne], having photosynthetic optima at 27° to 30°C, and exhibiting little or no photosynthesis below 10°C. The plants from the first group exhibit thermal injury at temperatures of 25°C and show a narrow tolerance to low salinities during periods of high temperatures. The plants from the second group show thermal injury at 30°C and have a wider tolerance to low salinities. The horizontal distribution of the 4 Polysiphonia species within the Great Bay Estuary System of New Hampshire, USA, is primarily governed by their tolerances to high temperatures and low salinities. The temperature optimum for each of the species corresponds to its particular estuarine distribution. Thus, P. subtilissima, having the highest temperature optimum, penetrated furthest into the Estuary, while P. lanosa, having the lowest temperature optimum, was restricted to the more coastal stations. There was a good correspondence between the natural distribution patterns and the manometric results.Published with the approval of the Director of the New Hampshire Agricultural Experiment Station as Scientific Contribution No. 731.Scientific Contribution No. 4 of the Jackson Estuarine Laboratory.     

Sequential development and exploitation of an exhaustible resource: do monopoly rights promote conservation?

This paper explores the problem of sequential exploitation of exhaustible resources by a monopolist, when a setup cost must be incurred to access the next pool. Under certain circumstances, the monopolist will always follow a more conservationist path of extraction and delay the introduction of new resource pools compared to a social planner. However, with other forms of consumer demand, the monopolist may exhaust the resource more quickly, especially if many new options will follow. These results may apply especially to depletable resources like antibiotics or biotech products, for which significant research and development costs are required, followed by monopoly rights conferred by patents.     

预防事故的行为干预技术及应用

行为干预技术是近来国外一种颇为盛行,效果甚好的以“人”为中心的事故预防方法。概要介绍此技术的研究现状、理论依据及要点、应用情况和在我国开展应用研究的方案设计     

矿山开采非线性沉陷学说初论

讨论基于岩体工程属性和矿山开采沉陷本质特征而建立非线性沉陷学说的正确性和可行性;总结了近年来笔者在非线性沉陷问题方面所做的大量实验、现场勘测、研究和取得的成果：采动岩体的非线性破坏特征、开采沉陷的Ｄａｍ ａｇｅ效应、采动岩体分形裂隙网络及演化规律、开采沉陷的协同效应和自组织过程、采动岩体层裂的突变机理、采动断层活化的分形界面效应、地表下沉的“Ｓ”型分形增长规律;提出了建立基于矿山开采非线性沉陷机理、规律的预测模型和防治对策及非线性沉陷学的学术思想     

矿井安全作业采用的填充密闭材料──泡沫树脂及其应用技术

泡沫树脂是一种新型安全填充密闭材料。以德国Ｉｓｏｓｃｈａｕｍ 型速凝泡沫树脂为例,分析与探讨了泡沫树脂材料的基本配方、性能、应用方法和应用范围以及我国在此领域的研究动向等问题。通过分析与研究发现,泡沫树脂具有良好的弹性、较低的透气性、不延燃、使用简便、可靠等优良特性,因此,建议我国矿山开采业尽快开发和应用这种新型安全填充密封材料     

车用汽油铅损害及其对策研究

针对车用汽油的抗爆性能要求,探讨四乙基铅（Ｐｂ（Ｃ２Ｈ５）４）抗爆添加剂的作用机理,并着重分析研究了由此而引起的发动机铅排放对人类造成的损害及给大气环境等带来的污染。还探讨了车用汽油铅损害的对策及其最新进展