番茄反夏栽培的营养特点及施肥技术研究

本试验在阳山县江英乡和清新县石湖镇４６０ｍ以上的石灰岩山区进行．试验得出．（１）番茄反夏栽培的营养特点：高产番茄养分吸收量远比低产番茄高，高产番茄吸氮２１６．４５ｋｇ／ｈｍ２，吸磷４０．２０ｋｇ／ｈｍ２，吸钾３９０．１５ｋｇ／ｋｍ２，吸收氮、磷、钾比例为１：０．１９：１．８０；（２）各生育期氮、磷、钾吸收规律：苗期吸收少，随生长期的推进而提高，尤其是番茄开花之后其提高的速度更快；（３）施肥技术：一造施肥总量，氮３６０．７５—４４４．４５ｋｇ／ｈｍ２，磷２２５．７５—２６７．９０ｋｇ／ｈｍ２，钾３４０．３５—４８７６５ｋｇ／ｈｍ２．各生育期合理配施的原则是前轻、中重、后补足．     

珠江口红树林硫的累积和循环研究

主要研究了珠江口红树林硫的累积和循环特点，并探讨其对土壤中硫累积的影响．结果表明，珠江口五个红树群落硫的贮存量平均为１７０．４２ｋｇ／ｈｍ２；在群落硫元素的生物循环中，年存留量平均为１７．６０１ｋｇ／ｈｍ２，年归还量平均为３５．６０３ｋｇ／ｈｍ２，年吸收量平均为５３．２０４ｋｇ／ｈｍ２，周转期为３－８ａ，富集率均大于１．选定浅海沉积物的平均含硫量作为林下土壤成土母质的本底含硫量，估算红树植物生长后土壤含硫量的变化，并与群落硫的年归还量作比较．红树林对其林下土壤硫的累积作用有两方面，一是对海水硫的生物选择吸收与归还，二是为海水中的ＳＯ４（２－）为黄铁矿提供有机还原剂和嫌气微生物的能源，尤以后者的作用更重要．     

草莓在有机与无机种植系统中的能流和经济效益的比较

本文运用了生态经济学的原理，对草莓在有机和无机种植系统内能量流动、物质转化以及经济效益进行了比较研究。结果表明：两处理区施用几乎相同氮量的有机肥（１７５ｋｇ／ｈｍ￣２）和无机肥（１６４ｋｇ／ｈｍ￣２），其有机区草莓的生长发育、产量均明显好于无机处理区；有机草莓的光能利用率和氮素产出／投入分别比无机草莓提高了６４．２４％和５７．７２％；同时证明，优质有机肥可改善草莓的良用品质，并提高经济效益。     

桉树人工林生态系统养分循环与平衡研究Ⅳ.桉树林间种山毛豆对生态系统养分循环的作用

桉树人工林间种山毛豆，增加了凋落物量和养分归还量，改善了营养元素的生物小循环。在一个轮伐期内山毛豆归还土壤养分的数量如下：氮528.37kg／hm^2，磷28.06kg／hm^2，钾66.20kg／hm^2，钙184.96kg／hm^2，镁57.21kg／hm^2；而同期刚果W5桉归还土壤养分的数量为：氮85.98kg／hm^2，磷3.94kg／hm^2，钾11.80kg/hm^2，钙36.98kg／hm^2，镁18.30kg／hm^2。由于间种山毛豆增加了生态系统的养分收入，减少了水土流失的养分支出，系统的各种养分出现了盈余的状况。     

闽东南旱地土壤养分状况与花生平衡施肥研究

２８个土壤样品的养分测定和吸附试验以及８个田间肥效试验表明，闽东南旱地土壤的Ｎ、Ｐ、Ｋ、Ｂ是花生的普遍养分限制因子．部分土壤还缺乏Ｚｎ和Ｍｇ等养分．赤砂土的肥料三要素最佳用量分别为Ｎ５４ｋｇ／ｈｍ２、Ｐ２Ｏ５５５ｋｇ／ｈｍ２、Ｋ２Ｏ８７ｋｇ／ｈｍ２；红壤性水稻土为Ｎ５２ｋｇ／ｈｍ２、Ｐ２Ｏ５６３ｋｇ／ｈｍ２、Ｋ２Ｏ９２ｋｇ／ｈｍ２；海砂土为Ｎ９４ｋｇ／ｈｍ２、Ｐ２Ｏ５４２ｋｇ／ｈｍ２、Ｋ２Ｏ８５ｋｇ／ｈｍ２．１０个对比试验表明，花生平衡施肥比群众常规施肥平均增产４７１ｋｇ／ｈｍ２，增产率为１４．９％，每ｈｍ２净增收２０５３元．     

湖南主要农田土壤中氮的形态

本试验采集了湖南省八种主要母质发育的２３个农田土壤耕层样本，其中水田土壤１６个，旱地土壤７个．将土壤氮分为七级．即交换性ＮＨ４＋十ＮＯ３－，水解性ＮＨ４＋，氨基糖氮，可溶性碱稳定态氮，酸溶性腐殖质态氮，固定态ＮＨ４＋，难溶性腐殖质态氮。分析结果表明，土壤中交换性ＮＨ４＋十ＮＯ３－的含量为２２．０土９．０ｍｇ／ｋｇ，占全氮的１．７土０．７％；水解性ＮＨ４＋为３２４．４土１０９．５ｍｇ／ｋｇ，占全氮的２３．９±５．６％；氨基糖氮为１１８．９土４３．０ｍｇ／ｋｇ，占全氮的９．１土３．２％；可溶性碱稳定态氮为４９７．１土２０５．８ｍｇ／ｋｇ，占全氮的３６．２土８．３％；酸溶性腐殖质态氮为２９．２土１０．２ｍｇ／ｋｇ，占全氮的１３土０．８％；固定态ＮＨ４＋为４７．２土２４．３ｍｇ／ｋｇ，占全氮的３．６±１．７％；难溶性腐殖质态氮为３４１．３土２７０．８ｍｇ／ｋｇ，占全氮的２２．２土１１．６％。     

烤烟优质高产施肥技术研究初报

１９９７～１９９８年在广东省五华县的紫色土田进行了烤烟优质高产施肥试验。结果表明,在一定的氮磷施用量条件下,烤烟的产量、质量及产值都是随着施钾比例的提高而提高。在一定的配比下,烤烟的产量及产值在施氮 １６５ ｋｇ／ｈｍ~２以下均随施氮量的增加而提高;均价和优级烟率以中等氮水平（ １３５ ｋｇ／ｈｍ~２）的为最高。本文还提出烤烟的最佳施肥方案。     

氮硫复合沉降对杉木幼苗营养元素的影响

采用随机区组设计模拟氮硫复合沉降实验,以CO(NH2)2为氮源、Na2SO4为硫源,模拟试验1年后,分别采集不同氮硫沉降水平下杉木枝和叶的样品,研究杉木幼苗在不同沉降水平影响下的生长以及枝和叶营养元素氮、磷、钾、钙和镁含量的变化及其相关性.结果表明:经过1年不同沉降水平处理后,幼苗胸径和地径在不同处理间差异显著(P0.05),均为促进作用,与对照相比,中氮低硫水平促进效果较佳;枝和叶中氮、磷和钾含量在不同处理间差异显著(P0.05),钙和镁在不同处理间差异不显著(P0.05);氮沉降源与叶氮、枝氮、叶磷含量相关关系极显著,相关系数分别为0.86、0.81、-0.78,与叶钾、枝镁含量呈显著负相关,相关系数分别为-0.64、-0.63;硫沉降源与叶磷(r=-0.62)含量呈显著负相关.叶中氮与磷、磷与钾、枝中氮和镁含量相关关系极显著,相关系数分别为-0.79、0.84、-0.91,叶中磷和镁、钾和镁以及枝中氮和磷、钾与钙含量呈显著相关,相关系数分别为0.65、0.70、-0.66、0.72,其他相关关系不显著.以上表明,中低氮硫沉降水平可有效提高杉木氮、磷、钾、钙、镁元素的含量.(图2表3参46)     

绿磺隆对水稻的残留危害剂量

用田间模拟试验法，研究了土壤中绿磺隆不同添加量与水稻危害剂量的关系。结果表明：稻田绿磺隆添加量超过０．３７５ｇ（ＡＩ）／ｈｍ￣２时，就可能对水用产生危害，在此用量水平下，绿磺隆在耕层土壤中的平均残留浓度为０．１７μｇ／ｋｇ，按此推算，麦田按正常用量的２倍量（３０ｇ／ｈｍ￣２）施用，在种麦期间绿磺隆在麦田土壤中的半衰期超过３２．１ｄ．即会对水稻产生危害。     

异丙隆在土壤和小麦中的降解与残留

在扬州和聊城两地进行了除草剂异丙隆在小麦上和麦田土壤中的残留动态和最终残留量试验，结果表明，异丙隆在小麦植株和土壤中消解较快，消解半衰期分别为３～４ｄ和８～１４ｄ；收获时小麦籽粒中异丙隆残留量小于０．０４ｍｇ／ｋｇ。推荐暂定异丙隆在小麦上ＭＲＩＬ值为０．５ｍｇ／ｋｇ。２５％异丙隆可湿性粉剂，按７．５ｋｇ／ｈｍ￣２用量，在次年早春（２月）使用，籽粒中异丙隆最终残留量不会超过ＭＲＬ值，对小麦是安全的。     

农桐复合经营的研究进展和趋势

论述了华北平原农桐复合经营的发展历史、现状和研究进展,提出了今后应该加强的研究领域     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.     

Threats to intact tropical peatlands and opportunities for their conservation

Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.     

Human Influence and Classical Biogeographic Predictors of Rare Species Occurrence

Biogeographic theory predicts that rare species occur more often in larger, less‐isolated habitat patches and suggests that patch size and connectivity are positive predictors of patch quality for conservation. However, in areas substantially modified by humans, rare species may be relegated to the most isolated patches. We used data from plant surveys of 81 meadow patches in the Georgia Basin of Canada and the United States to show that presence of threatened and endangered plants was positively predicted for patches that were isolated on small islands surrounded by ocean and for patches that were isolated by surrounding forest. Neither patch size nor connectivity were positive predictors of rare species occurrence. Thus, in our study area, human influence, presumably due to disturbance or introduction of competitive non‐native species, appears to have overwhelmed classical predictors of rare species distribution, such that greater patch isolation appeared to favor presence of rare species. We suggest conservation planners consider the potential advantages of protecting geographically isolated patches in human‐modified landscapes because such patches may represent the only habitats in which rare species are likely to persist. Influencia Humana y Predictores Biogeográficos Clásicos de la Ocurrencia de Especies Raras     

Seasonal dynamics of macro-algae in the South Lake of Tunis

The macro-algae communities observed in the south lake of Tunis are characterized by the predominance of nitrophilous algae which are in the order of biomass importance:Ulva, Cladophora andEnteromorpha. We have noted seasonal changes of alga distribution. The wind appears to be one of the most important factors influencing this distribution. The total biomass reaches a maximum in the spring. Rapid decomposition of the biomass leads to a severe ecological imbalance, resulting in crises of anoxia and fish death. A restoration project has already started. It aims at removal of contaminated muds and the introduction of a new circulation system. The main objectives of this work were to collect information on the distribution and biomass of the phytobenthic communities as a first step in the constitution of a database for further comparison.     

Patterns and biases of climate change threats in the IUCN Red List

International Union for Conservation of Nature (IUCN) Red List assessments rely on published data and expert inputs, and biases can be introduced where underlying definitions and concepts are ambiguous. Consideration of climate change threat is no exception, and recently numerous approaches to assessing the threat of climate change to species have been developed. We explored IUCN Red List assessments of amphibians and birds to determine whether species listed as threatened by climate change display distinct patterns in terms of habitat occupied and additional nonclimatic threats faced. We compared IUCN Red List data with a published data set of species’ biological and ecological traits believed to infer high vulnerability to climate change and determined whether distributions of climate change‐threatened species on the IUCN Red List concur with those of climate change‐threatened species identified with the trait‐based approach and whether species possessing these traits are more likely to have climate change listed as a threat on the IUCN Red List. Species in some ecosystems (e.g., grassland, shrubland) and subject to particular threats (e.g., invasive species) were more likely to have climate change as a listed threat. Geographical patterns of climate change‐threatened amphibians and birds on the IUCN Red List were incongruent with patterns of global species richness and patterns identified using trait‐based approaches. Certain traits were linked to increases or decreases in the likelihood of a species being threatened by climate change. Broad temperature tolerance of a species was consistently related to an increased likelihood of climate change threat, indicating counterintuitive relationships in IUCN assessments. To improve the robustness of species assessments of the vulnerability or extinction risk associated with climate change, we suggest IUCN adopt a more cohesive approach whereby specific traits highlighted by our results are considered in Red List assessments. To achieve this and to strengthen the climate change‐vulnerability assessments approach, it is necessary to identify and implement logical avenues for further research into traits that make species vulnerable to climate change (including population‐level threats).