野生马齿苋种子发芽试验

本文对野生马齿苋种子的发芽特性进行了初步研究,结果表明,马齿苋种子发芽受温度、浸种时间、种子贮藏时间等因素影响.温度低于20℃时,不发芽,20℃时开始发芽,发芽适温为25～30℃,温度超过35℃时发芽受到抑制,在25℃下催芽,其发芽时间集中在24～48h内.温水浸种有利于发芽,浸种时间以12～24h为宜.马齿苋种子存在3～4个月的生理休眠期,用清水浸种可打破休眠,野外播种马齿苋时覆盖塑料小拱棚可明显提高发芽率和出苗率.     

4个岷江柏种群的球果和种子形态特征及其地理空间差异

研究了我国四川和甘肃地区特有珍稀濒危植物岷江柏(Cupressus chenggiana S.Y.Hu)的4个地理种群球果和种子的形态特征，分析了不同生境条件下岷江柏的地理差异．结果表明：岷江柏球果呈椭球形，长(l)为1．5～2．5cm，宽(6)为1．5～2．0cm，重(m)为1．5～4．5g，球果鳞片数为8～11片，球果内种子粒数为40～70粒．在调查的4个岷江柏种群中，小金县种群的球果最大、球果内种子数最多，马尔康县种群和金川县种群的球果重量、球果内种子数居中，理县种群的球果最小、球果内种子数最少．讨论认为，4个种群球果和种子大小特征存在极显著差异，不同种群球果和种子的形态差异与岷江柏的种群遗传特征、气候特征和生境特征有着密切的关系．图3表7参25     

蓝白龙胆种子萌发影响因素分析

采用室内控制实验研究了蓝白龙胆种子萌发对种子贮藏时间、萌发温度、土壤水分、光照强度、土层厚度的响应.结果显示:贮藏时间、萌发温度、土壤水分、光照强度和土层厚度均影响种子萌发.(1)种子成熟后0~30 d萌发率最高,之后随贮藏时间增加其萌发率开始下降,180 d后萌发率不足3%;(2)种子萌发温度幅较宽,10~30℃均能使其萌发;(3)随土壤含水量的增加,种子萌发率呈现先增加后降低的趋势,20%~25%土壤含水量是种子萌发的最佳湿度;(4)光照促进种子萌发,但黑暗抑制其萌发;(5)随土层厚度的增加,萌发率显著降低.实验结果说明蓝白龙胆种子萌发受许多因素影响,是长期适应生境的结果.     

聚乙二醇(PEG)模拟干旱胁迫对干旱河谷5种木蓝种子萌发的影响

以川西干旱河谷地区的5种木蓝属植物的种子为材料,观测其形态特征以及聚乙二醇(PEG-6000)模拟干旱胁迫对种子萌发的影响.实验结果表明,供试木蓝属植物种子的物理特征(大小、千粒重)与萌发特性之间无显著相关性,而种子硬实率与发芽率则显著相关;不同浓度的PEG胁迫对种子的萌发均有一定的延缓作用,并且种子的发芽率、发芽势和发芽指数均随胁迫强度的增加呈现下降趋势。综合比较5种木蓝植物种子的抗旱性,在PEG浓度低于150g/L的轻度干旱胁迫下抗旱性由强到弱依次为:刺序木蓝河北木蓝≈灰色木蓝≈四川木蓝多花木蓝;与采自茂县岷江河谷的刺序木蓝相比,来源于泸定大渡河河谷的刺序木蓝的种子萌发对土壤水分的要求较低,并且相同水分条件下后者发芽率、发芽势和发芽指数也显著高于前者,这可能与各自的种源地在气候、水分及土壤条件上的差异有关.     

赤霉素浓度对色木槭(Acer mono Maxim.)种子萌发的影响

岷江上游彩叶林生态系统是我国西南地区特有的关键生态系统类型,具有水源涵养、水土保持和气候调节等重要的生态功能,而且具有显著的景观美学价值,是区域特色生态旅游经济的重要基础.由于受到自然灾害破坏和水电站的修建等人为干扰,目前岷江上游彩叶林系统毁坏严重且残存量不多,亟待恢复和重建.色木槭(Acer mono Maxim.)是川西地区彩叶林生态系统的代表性树种,探究其种子萌发特性对岷江上游彩叶林系统的恢复重建具有重要意义.种子萌发实验在人工气候箱内进行,采用0、100、200、300、400、500 mg/L 6个赤霉素浓度对色木槭种子进行浸种处理,在25℃条件下进行萌发,统计种子萌发率、发芽势和发芽指数,并测定色木槭种子在萌发过程中内部贮藏物质可溶性糖、可溶性蛋白、淀粉和淀粉酶活性的变化.结果显示,色木槭种子在200 mg/L浓度赤霉素浸种24 h后,其萌发率为29.33%±1.89%,发芽势为9.66%±1.25%,发芽指数为8.69±8.32,均显著高于对照水平.本研究表明赤霉素浓度对色木槭种子的可溶性蛋白含量、淀粉含量和淀粉酶活性影响显著,对可溶性糖含量无显著性影响;种子内部贮藏物质含量在不同的萌发时期有显著差异.色木槭种子的最适赤霉素浓度为200 mg/L,在生产中使用200 mg/L赤霉素浸种能有效增加色木槭的萌发率.上述结果可为色木槭的快速繁育和亚高山彩叶林恢复重建提供技术支持.(图3参25)     

不同温度处理对金钟藤种子萌发的影响

主要研究了恒温25、28、30℃不同处理下温度对金钟藤种子荫发的影响，并采用发芽率、发芽指数、活力指数、芽长和胚根长等指标对金钟藤种子发芽效果进行了评价。结果表明，随着温度的升高，金钟膝种子发芽率、发芽指数、活力指数均上升。此外，随着温度的升高，芽和胚根出现不同的生长趋势，芽生长增加而根生长减少，进一步显示其地上部分受温度影响会加快生长，预示其入侵危害可能加剧。鉴于金钟膝日前在广州的危害情况，文章提出应将金钟滕列为潜在的入侵植物，加强研究，尽早开展预防和控制措施。     

长期施肥潮土土壤呼吸的温度和水分效应

温度和水分是影响土壤呼吸的重要因素.利用室内培养试验研究因长期施用不同肥料造成有机质含量存在差异的土壤在不同土壤水分含量(30%WFPS、45%WFPS、60%WFPS、75%WFPS 和90%WFPS)和培养温度(5 ℃、15 ℃、25 ℃、35 ℃)下的土壤呼吸.结果表明,土壤水分含量和培养温度对土壤呼吸既表现出相互制约作用,在一定范围内又具有相互促进作用.施肥影响着土壤呼吸所需的最适水分含量,不均衡施肥处理的土壤呼吸所需最适土壤水分含量高于均衡施肥处理的土壤.培养温度也影响土壤呼吸的最适水分含量,土壤呼吸所需最适水分随培养温度升高而升高.土壤水分含量的增加可增加土壤呼吸的Q10.施肥特别是施有机肥而增加的土壤有机碳的释放速率是最快的.因此,气温升高和降水增加等气候变化趋势下,不利于通过施用有机肥来增加农田土壤有机碳储量.     

不同环境温度条件对脱水污泥堆肥效果的影响研究

为明确不同环境温度对脱水污泥堆肥效果的影响,试验采用双层反应器进行水浴保温模拟不同环境温度,分别设置10℃(CT10)和25℃(CT25)两个处理并运行30 d,通过分析污泥堆肥过程中温度、pH、总氮、C/N比值、腐殖酸含量等指标变化特征,比较两个处理的污泥腐熟效果。结果表明:CT25堆肥处理进入55℃高温期并维持8 d,较CT10处理提前3 d达到高温期并多维持3 d;两个处理堆体的pH值变化范围为7.10~7.91,呈先升后降趋势,且CT25处理pH值的升高、降低幅度更大;两种堆肥处理有机质和总氮含量呈降低趋势,且同一时期CT25处理低于CT10,其中18 d取样时两处理有机质含量呈显著性差异(P0.05),两处理总氮在堆肥各时期没有呈现显著差异(P0.05);整个运行期间,堆体腐殖酸含量呈增加趋势,堆肥结束时,CT25处理的腐殖质含量达24.18%,较CT10处理提高5.52%;通过T值(T=(C/N)终/(C/N)始0.6)判断两处理的污泥腐熟程度,结果显示,第18天时CT25处理的T值为0.59,堆体达到腐熟,CT10处理在第30天时才达到腐熟。上述结果表明,利用该反应器进行脱水污泥堆肥,较高温度启动可以实现污泥更快速、充分腐熟。通过对脱水污泥堆肥反应器启动温度的控制,可为低温条件下脱水污泥的快速腐熟控制提供参考。     

金沙江干热河谷地区不同含油量麻疯树种子的差异性

根据金沙江干热河谷地区麻疯树种子的含油量,将麻疯树种子分为组Ⅰ(26%~30%)、组Ⅱ(30%~34%)、组Ⅲ(34%~38%)、组Ⅳ(38%~42%).该地区种子体积介于1.544~1.680 cm3之间;其中组Ⅱ的种子最大(1.680 cm3),组Ⅳ的种子最小(1.544 cm3).组Ⅱ种子的百粒重同样为最高(69.367 g),组Ⅲ的种子最轻(62.313 g).出仁率从低到高依次为:组Ⅰ(61.752%)<组Ⅲ(63.352%)<组Ⅱ(64.132%)<组Ⅳ(65.192%).百粒种子产油量从组Ⅰ到组Ⅳ逐渐升高(17.731~25.342 g).1H-NMR图谱分析发现,各组种子之间的脂肪酸组成无明显差异,而脂肪酸成分的含量存在显著差异.种子的发芽势、发芽率和发芽指数随含油量的增加而升高,种子的吸胀速率则相反.种子含油量与种子大小的相关性不显著,与种子质量、出仁率、种子产油量、脂肪酸组成、发芽势、发芽率、发芽指数和吸胀速率之间则都有着极显著的相关性.图3表4参30     

外源ABA对不同品种辣椒种子萌发的影响

以4种辣椒种子为试验材料,研究了不同浓度ABA(0~100 mg/L)对种子萌发的影响.结果表明:低浓度ABA对种子的发芽势和发芽率没有显著影响,高浓度ABA极显著抑制种子的发芽势和发芽率,辣椒品种(系)不同,种子萌发对ABA浓度的敏感性也不同.不同浓度ABA溶液极显著降低了种子的发芽指数,随着ABA浓度的增加,对发芽指数的抑制程度逐渐加强,种子的发芽起始时间也被推迟,浓度越高,萌发延迟天数越多.ABA溶液极显著抑制种子胚根和胚轴的分化和生长,ABA浓度越高,抑制程度越强.图6,表1,参17.     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Representation of the world's biophysical conditions by the global protected area network

Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.     

Quantitative composition of the defensive secretion ofBledius species (Coleoptera: Staphylinidae: Oxytelinae) is adapted to naturally occurring predators

Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.     

Democracy versus development: New urban debates

The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.     

A framework to measure the wildness of managed large vertebrate populations

As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

Sexual Predators,Energy Development,and Conservation in Greater Yellowstone

Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.     

Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus,a bruchid beetle pest of kidney beans

Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.     

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.