稻-虾(克氏原螯虾)综合种养模式的碳足迹分析

探明稻-虾(克氏原螯虾)综合种养模式的碳足迹大小及其构成特征,对促进稻-虾综合种养低碳发展具有重要意义。该研究采用问卷调查法,运用碳足迹理论系统分析稻-虾生产模式碳足迹产生及其构成,并进一步分析其主要影响因素。结果表明:稻-虾生产模式下单位面积碳足迹为7 859 kg·hm~(-2)(以CO_2当量计,全文同),介于稻-麦(10 650 kg·hm~(-2))和单季稻生产模式(5 483 kg·hm~(-2))之间;单位产值和单位利润碳足迹分别为0.11和0.26 kg·元~(-1)(以CO_2当量计,全文同),分别比稻-麦和单季稻生产模式降低64.26%、60.65%和67.37%、45.02%。与稻-麦相比,稻-虾生产模式显著降低直接碳排放,间接碳排放无显著性差异;与单季稻相比,稻-虾生产模式显著提高间接碳排放,对直接碳排放无显著影响。稻-虾生产模式下,碳足迹大小与虾产量、产值和利润呈"抛物线"型变化趋势,在碳足迹为7 458、7 855和7 363 kg·hm~(-2)时能够分别获得产量、产值和利润最大化。生产规模对稻-虾生产模式碳足迹具有显著影响,小规模(5.00 hm~2)和大规模(20.00 hm~2)生产有利于降低碳足迹、提高产值和利润。总之,相对于传统稻田生产方式,稻-虾生产模式能够有效减排增效,但应关注碳足迹与经济效益之间的权衡点,促进稻-虾生产模式的绿色高效发展。     

杂交油菜施用粉煤灰磁化肥的效应

通过对杂交油菜施用粉煤灰磁化复合肥的试验研究,初步探明了粉煤灰磁化复合肥较同等N、P、K的复混肥,未磁化粉煤灰复合肥及当地群众习惯施肥法有显著的增产效果.试验表明,粉煤灰磁化肥在油菜上一般用量为757.58kg/hm2左右.粉煤灰磁化肥比对照增产21.9%,比当地农民习惯施肥措施增产10.5%;比等量N、P、K混合肥增产9.9%,增产180kg/hm2.比未磁化粉煤灰复混肥增产4.5%.最高产量施用粉煤灰磁化肥为1026.9kg/hm2,油菜产量为2084.85kg/hm2;最佳产量施用粉煤灰磁化肥为757.58kg/hm2,油菜产量为2041.79kg/hm2.     

水稻与水合欢间作对作物群体产量、氮素吸收及土壤氮素的影响

豆科与禾本科作物间作有利于提高氮素利用率及作物群体产量。旱地条件下豆科与禾本科作物间作产量优势的研究已多见报道,但水田环境下水稻(Oryza sativa)与豆科水生作物间作模式的研究报道甚少。在华南地区水田条件下分别构建了2015年晚稻和2015年早稻水稻与水合欢(Neptunia olerace)间作模式,并探讨该模式对产量和稻田土壤氮素的影响。试验设常规施氮水稻单作(N 180 kg·hm~(-2),CK)、低氮水稻单作(N 140 kg·hm~(-2),LRM)、水稻-水合欢间作(N140 kg·hm~(-2),LRN)和水合欢单作(N 140 kg·hm~(-2),NOM)4种处理,测定不同种植模式下的作物产量、吸氮量、土地当量比及稻田土壤全氮含量的变化。结果表明,间作栽培模式下的水稻茎蘖数、叶面积指数和地上部生物量均显著高于CK和LRM,其中与水合欢相邻的边行水稻茎蘖数、叶面积、地上部生物量和产量均显著高于内行。水稻实地面积产量表现为LRNCKLRM,LRN处理下水合欢实地面积产量低于NOM。2014年晚稻和2015年早稻,以LRN、NOM和CK计算的土地当量比分别为1.01和1.20,以LRN、NOM和LRM计算的土地当量比分别为1.12和1.25,表明间作模式下作物整体产量明显提高。LRN处理下水稻群体总吸氮量显著低于CK和LRM,经过两季种植后,LRN处理下土壤全氮含量分别比CK和LRM提高了0.21%和1.69%。在水田环境中,水稻与水合欢间作在低氮投入下能维持较高的土地当量比,且提高了作物群体产量和土壤全氮。     

吉林西部盐碱水田区全球变暖潜势研究

为了探讨吉林西部土地整理工程对区域全暖所做贡献,基于实测的水田土壤温室气体数据,进行区域温室气体排放分析,为进一步评估水田开发对全球变暖的影响提供科学依据。以吉林省西部盐碱水田区为研究对象,将野外调查采样和小区试验相结合,采集了水田的0-30 cm表层土壤样品带回进行小区实验。在小区内挖取100 cm×100 cm×50 cm的坑,在土坑底部铺设塑料布后,将从采样点带回的土壤填进坑内灌水,种植水稻,6块样地分别为不同开发年限,其处置模式与前郭当地的水肥管理相同,样地周围挖掘了排水渠。通过静态箱-气相色谱法监测水稻生长期土壤所释放的温室气体 CH4,N2O 和CO2,计算水稻不同生长时期温室气体排放量及贡献率,估算研究区的区域变暖潜势（GWP）,结合30年水田面积变化加权法分析温室气体GWP贡献率。结果表明：水田生长期温室气体排放总量（以CO2气体计）随着开发年限的增加呈递增趋势,水田开发过程中CO2、CH4和N2O各时期温室气体排放的贡献率都有一定变化,CO2气体排放贡献率占主导地位在80%左右,CH4的贡献率16.69%-20.39%,是N2O的14-22倍,水田CH4气体的排放对研究区综合温室效应有较大贡献,水田开发初期N2O气体贡献率较成熟水田相比较高。在水稻生长旺盛期CO2气体贡献率下降明显,CH4气体贡献率显著升高,N2O气体贡献率变化不大,在返青期和成熟期CH4和N2O 2种气体贡献率均较小,其中,除成熟期外新开发水田的CH4气体贡献率均高于成熟水田,在水稻生长发育较快速的分蘖期、拔节孕穗期和抽穗开花期,CO2气体贡献率下降且降幅明显,该阶段CH4气体对温室效应的贡献比重加大,远高于N2O气体。在水稻成熟期,3种温室气体的贡献率与其他时期相比发生较大变化,CH4比 N2O 略有优势,CO2所占比例恢复至95%。?     

川中丘陵区稻田甲烷排放及其影响因素

利用静态箱/气相色谱法对川中丘陵区冬水田和水旱轮作稻田进行全生长季CH4排放观测。结果表明,水旱轮作稻田和冬水田CH4排放的季节变化峰值都出现在水稻生长中期,且都有1个典型的排放峰。分析讨论了温度、水稻生物量、耕作制度以及水稻栽培方式等因素对稻田CH4排放的影响。发现川中丘陵水稻生长季节5cm深处地温与稻田CH4排放通量呈显著正相关;水稻植株生长对CH4排放有重要作用;水旱轮作稻田CH4排放通量比冬水田低54.1%～65.1%;冬水田水稻采用强化栽培方式既可提高产量又可减少CH4排放。     

盐碱地农-渔开发对土壤环境的影响

在东北苏打盐碱地进行了稻-鱼-苇-蒲开发试验,并探讨了该模式对盐碱土壤环境的影响。结果表明,开发后土壤有机质含量增加96.8%(平均值,以下同),盐分含量下降43.6%,全量和速效N、P、K质量分数分别增加142.8%和188.2%;阳离子交换量、盐基总量分别增加8.21%及27.71%;土壤腐殖质以富里酸为主,w(HA)/w(FA)比值提高36.15%;养鱼稻田的土壤微生物总量明显高于未养鱼田(P<0.01);优势种为放线菌。土壤酶活性进一步加强。系统废水的盐分质量浓度降至1.0 g/L左右,碱浓度低于水源(7.0~10.0 mmol/L)。该模式不会造成土壤次生盐碱化。     

一稻两鸭共作对稻田土壤养分动态的影响

鸭稻共作是有效减少化肥和农药施用的重要技术,对稻田土壤养分消耗具有一定的缓冲和调控作用。但在鸭稻共作有机生产模式中,外源性化肥投入的缺乏常常成为水稻高产的限制因素。为更好地解决有机种植中土壤养分供应的问题,对常规鸭稻共作进行了调整,建立了2种＂一稻两鸭＂共作生态农业模式。通过田间试验对常规稻作、常规鸭稻共作、一稻两鸭轮养及一稻两鸭套养4种种植模式下的土壤养分进行定位监测。结果表明：相对于常规稻作,3种鸭稻共作模式均能在一定程度上提高土壤全钾、全氮的含量,同时减小碱解氮的消耗。与比生产前期相比,生产结束后常规水稻种植模式下土壤有机质含量有所下降,而3种鸭稻共作模式下土壤有机质含量比生产前期均有不同程度的增加。4种种植模式下土壤全磷含量在生产结束后均有不同程度的下降,然而一稻两鸭套养和一稻两鸭轮养模式下土壤全磷含量的降低程度低于常规稻作。早稻生产结束后,一稻两鸭套养和一稻两鸭轮养模式下的土壤全磷含量比常规稻作分别高出13.53%和11.01%。与常规鸭稻共作模式相比,一稻两鸭轮养和套养模式增加了全氮以及全钾有机物的积累,同时减缓了碱解氮、速效磷、速效钾含量的下降。晚稻生产结束后,一稻两鸭套养模式下土壤碱解氮、速效磷和速效钾的含量分别比常规鸭稻共作模式高出3.7%,10.39%和7.59%。产量测定结果表明,早稻时期一稻两鸭套养模式下的水稻产量比常规鸭稻共作模式高12.90%,晚稻时期则比常规鸭稻共作高12.19%。一稻两鸭共作模式中,由于两批鸭子的存在,其排便和中耕作用几乎贯穿于水稻的整个生长发育过程,因此培肥效果与常规鸭稻共作相比有了进一步的提高,对系统内的养分循环利用起到了更好的促进作用。     

密度和品种对玉米田杂草及玉米产量的影响

通过对玉米田杂草的调查,研究了不同密度和品种对玉米田杂草种类和生物量变化及玉米产量的影响。结果表明:在玉米全生育期内共发现以稗草(Echinochloa colonum(Linn.)Link)、水花生(Alternanthera philoxeroides)、水芹(Lepidiumsativum)等为主的21种杂草,以水芹的重要值最高;随密度的增加杂草的总数量和鲜质量减少;半紧凑型品种对杂草数量和生物量的抑制作用大于紧凑型品种,且产量高出了21.99%。密度对玉米产量的影响差异不显著,以B3(57 000株/hm2)产量最高,比常规密度B1(42 000株/hm2)和高密度B4(64 500株/hm2)的产量提高了14.17%和0.6%。可见,应根据玉米的品种类型,因地制宜地确定适宜的种植密度,以利于高产稳产。     

密度和品种对玉米田杂草及玉米产量的影响

通过对玉米田杂草的调查,研究了不同密度和品种对玉米田杂草种类和生物量变化及玉米产量的影响。结果表明：在玉米全生育期内共发现以稗草（Echinochloa colonum（Linn.）Link）、水花生（Alternanthera philoxeroides）、水芹（Lepidiumsativum）等为主的21种杂草,以水芹的重要值最高;随密度的增加杂草的总数量和鲜质量减少;半紧凑型品种对杂草数量和生物量的抑制作用大于紧凑型品种,且产量高出了21.99%。密度对玉米产量的影响差异不显著,以B3（57 000株/hm2）产量最高,比常规密度B1（42 000株/hm2）和高密度B4（64 500株/hm2）的产量提高了14.17%和0.6%。可见,应根据玉米的品种类型,因地制宜地确定适宜的种植密度,以利于高产稳产。     

水稻产量对双季稻-不同冬绿肥轮作及环境的响应

双季稻和冬季绿肥轮作体系是实现南方稻区水稻高产、稳产可持续发展的重要措施。为探讨水稻产量对双季稻-不同冬季绿肥轮作及环境的响应特征,以开始于1982年的双季稻-不同冬季绿肥(稻-稻-紫云英,R-R-MV;稻-稻-油菜,R-R-RP;稻-稻-黑麦草,R-R-RG;稻-稻-冬闲,R-R-WF)的长期定位试验为平台,采用产量变异系数(CV)、产量可持续指数(SYI)及AMMI模型对影响双季稻稻谷总产量稳定性的双季稻-不同冬季绿肥轮作、环境和二者互作进行分析,研究稻谷产量对长期双季稻-不同冬季绿肥轮作的响应特征。结果表明:双季稻-不同绿肥轮作稻谷产量变异系数随试验时间延长逐渐降低,与其他绿肥轮作模式相比,稻-稻-紫云英轮作能够减小产量变异系数。早稻和晚稻均以稻-稻-紫云英处理的SYI值最高,分别为0.58和0.59。双季稻-不同绿肥轮作与年际间环境的互作(F×E)平方和占总平方和的2.3%,达到了显著差异(P=0.012 5)。双季稻-不同绿肥轮作方式和交互作用对水稻产量的影响相对较小,影响水稻产量变化的主要因素是年际气候因子变化,稻-稻-紫云英轮作更能积极适应气候因子的变化。综合以上分析结果,认为稻-稻-紫云英轮作是该区域双季稻高产和稳产的理想轮作制度。     

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.