Holocene dynamics of invertebrate fauna in the littoral zone of Adak,the Aleutian Islands,according to archaeozoological data

Studies on invertebrate remains from the cultural layer of an ancient Aleut settlement on Adak Island have shown that the faunistic composition of invertebrates in the study area had not changed significantly during the Late Holocene. The traditional mode of natural resource use by the ancient Aleuts had no impact on the abundance of valuable species and biodiversity in general. Changes in the temperature regime were found to have taken place in the history of deposit formation. The period from the 8th to the mid-11th century was relatively cold. Climate warming took place between the mid-11th and the mid-12th centuries and between the mid-16th and the 19th centuries, with an intervening cooling period (from the mid-12th to the mid-16th century). This cooling was most distinct between the 15th and the mid-16th centuries.     

南沙群岛海域沉积物环境与间隙水中的铁锰

研究了南沙群岛海域泻湖及礁外沉积物间隙水中的Ｆｅ＾２＋、Ｍｎ＾２＋、浓度及其比值、沉积物－海水界面扩散通量、沉积物类型及其氧化还原环境。结果表明，间隙水中的Ｆｅ＾２＋、Ｍｎ＾２＋浓度泻湖高于礁外，Ｆｅ＾２＋（礁）／Ｆｅ＾２＋（泻）浓度比为０．２８，Ｍｎ＾２＋（礁）／Ｍｎ＾２＋（泻）浓度比为０．６６，Ｍｎ＾２＋／Ｆｅ＾２＋比值泻湖内为１．４７，礁外为３．５２，Ｆｅ＾２＋、Ｍｎ＾２＋均是从沉积物向上覆     

Comparison of three chemical tests to assess seed viability: the seed dispersal system of the Macaronesian endemic plant <Emphasis Type="Italic">Rubia fruticosa</Emphasis> (Rubiaceae) as an example

Summary. Three chemical viability tests were evaluated in the seed dispersal system of Rubia fruticosa, in which three main groups of dispersers participate: reptiles, birds and mammals. Tetrazolium chloride (TTC) and indigo carmine (IC) indicated a lower viability of seeds from droppings of introduced rabbits (Oryctolagus cuniculus) than of those from control plants and the native dispersers, lizards and gulls. In the rabbit seed treatment, significant differences were observed between results obtained with TTC and IC tests. Interpretation of these data, due to the presence of doubtful embryo staining, was more difficult using the IC test. Furthermore, some seeds that were clearly dead had been underestimated. In contrast with results obtained from the two staining methods, the EC test did not confirm that viability of control seeds and those seeds consumed by native dispersers were clearly higher than in seeds ingested by O. cuniculus. Further, compared to the other two tests, the EC method requires more careful handling of the embryo during the extraction process to avoid errors in viability estimation, since this method measures concentration of electrolytes that are released through cellular membranes. Thus, TTC was the most reliable test to assess seed viability in the seed dispersal system of R. fruticosa, and these results agree with those obtained in previous germination experiments made on the same set of seeds given the same treatments.     

Culture and the environment on the Cape Verde Islands

The Cape Verde Islands originally supported a limited island ecology which, since the arrival of settlers 500 years ago, has been steadily altered or destroyed. Today, deforestation and overfarming, combined with the natural conditions of aridity and strong winds, have rendered the islands barren and eroded. The current government of the Republic of Cape Verde is attempting to alter traditional attitudes and customs of environmental neglect and mismanagement, while at the same time striving to restore or create self-sustaining ecosystems. The introduction of plants, animals, and physical structures enhancing soil and water conservation may create a more viable total ecosystem than existed before humans arrived.     

Phalaris arundinacea L. (Reed canary grass—Gramineae) as a hydrophyte in Essex,Connecticut, USA

After the June 1982 floods in Essex, Connecticut, USA, reseeding for stabilization of exposed pond bottoms and subsequent rebuilding of a dam on the Mill Pond, Essex, CT resulted in rooted, floating aquatic mats ofPhalaris arundinacea L. This required that the site be weed harvested to restore open water. It is suggested that the species not be used to temporarily stabilize pond bottom soils because of its great and unexpected adaptability to aquatic situations.     

Change in environmental stability and the use of resources on small islands: The case of Formentera,Balearic Islands,Spain

Since the beginning of the 1960s, mass tourism has been the most important menace to the environmental stability of fragile and vulnerable Mediterranean microinsular systems. The socioeconomic changes introduced by tourism have produced important variations in the use of resources, including land. The result usually has been an increase in the level of artificiality of the territory, particularly in coastal areas. The intensity and frequency of change in the use of resources and the induced changes in the level of artificiality may be used as an estimation of environmental stability. The northern area of Formentera, Balearic islands, Spain, being the most environmentally important area of the island and simultaneously the most threatened by mass tourism development, has been chosen as a study case. Forty types of vegetation and land use have been estimated and mapped in the area. The stability level of each land use type has been estimated, before and after the development of tourism, and the main environmental processes have been identified. An attempt is made to predict some future trends and their variations.     

Microbial communities and immigration in volcanic environments of Canary Islands (Spain)

Volcanic eruptions originated the Canary Islands (Spain), and today, different landscapes clearly show that active volcanism. The microbial communities present in these volcanic environments, both at high (above 70 degrees C) and moderate (25-35 degrees C) temperatures, were analyzed. Rock samples were processed using molecular techniques based on both DNA and RNA and complemented with the culture of microorganisms at a wide range of temperatures. Microorganisms detected through RNA-based molecular surveys were mostly related to mesophilic microorganisms, while representatives of hyperthermophiles were not detected. RNA decay curves at 80 degrees C resulted in half-life estimates of less than 2 min for mesophilic microorganisms, supporting a recent and continuous arrival of microorganisms to the high temperature sampled sites. This study constitutes a unique experimental approach showing a great natural potential of microorganisms to spread out to different natural environments. The implications are of great interest for the biogeography, dispersal, and potential distribution of microorganisms, and their genetic information, in natural environments.     

人工浮岛技术应用前景

人工浮岛技术是近年来发展迅速的一种生态污水处理技术,在国内外有许多报道。本文概括了人工浮岛技术的最新国内外研究进展,对人工浮岛技术存在的问题进行了分析,并对人工浮岛技术的应用前景进行了展望。     

Bird pollination of Canary Island endemic plants

The Canary Islands are home to a guild of endemic, threatened bird-pollinated plants. Previous work has suggested that these plants evolved floral traits as adaptations to pollination by flower specialist sunbirds, but subsequently, they appear to have co-opted generalist passerine birds as sub-optimal pollinators. To test this idea, we carried out a quantitative study of the pollination biology of three of the bird-pollinated plants, Canarina canariensis (Campanulaceae), Isoplexis canariensis (Veronicaceae) and Lotus berthelotii (Fabaceae), on the island of Tenerife. Using colour vision models, we predicted the detectability of flowers to bird and bee pollinators. We measured pollinator visitation rates, nectar standing crops as well as seed-set and pollen removal and deposition. These data showed that the plants are effectively pollinated by non-flower specialist passerine birds that only occasionally visit flowers. The large nectar standing crops and extended flower longevities (>10 days) of Canarina and Isoplexis suggests that they have evolved a bird pollination system that effectively exploits these low frequency non-specialist pollen vectors and is in no way sub-optimal. Seed set in two of the three species was high and was significantly reduced or zero in flowers where pollinator access was restricted. In L. berthelotii, however, no fruit set was observed, probably because the plants were self-incompatible horticultural clones of a single genet. We also show that, while all three species are easily detectable for birds, the orange Canarina and the red Lotus (but less so the yellow-orange Isoplexis) should be difficult to detect for insect pollinators without specialised red receptors, such as bumblebees. Contrary to expectations if we accept that the flowers are primarily adapted to sunbird pollination, the chiffchaff (Phylloscopus canariensis) was an effective pollinator of these species.     

Cascading loss and loss risk multipliers amid a changing climate in the Pacific Islands

Human society has experienced, and will continue to experience, extensive loss and damage from worsening anthropogenic climate change. Despite our natural tendencies to categorise and organise, it can be unhelpful to delineate clean boundaries and linear understandings for complex and messy concepts such as loss and damage. Drawing on the perspectives of 42 local and regional Pacific Islander stakeholders, an underexplored resource for understanding loss and damage, we explore the complexity and interconnectedness of non-economic loss and damage (NELD). According to participants, Pacific Islander worldviews, knowledge systems and cosmologies often make it difficult to separate and evaluate NELD independently, challenging the nomenclature of NELD categories developed through international mechanisms. Instead, NELD understandings are often centred on the interdependencies between losses, including the cascading flow-on effects that can occur and the nature of some losses as risk multipliers (i.e. one loss creating the risk for further losses). Most notably, losses to biodiversity, ecosystem services and land are critically linked to, and have cascading effects on, livelihoods, knowledge, ways of life, wellbeing, and culture and heritage. We argue that loss and damage is not always absolute, and that there are NELD that are arguably reparable. Concerning, however, is that biodiversity loss, as a risk multiplier, was considered the least reparable by participants. We put forward that NELD understandings must consider interconnectivity, and that biodiversity and ecosystem conservation and restoration must be the focus for interventions to prevent irreparable and cascading losses from climate change in the Pacific Islands.