土壤中毒死蜱及主要代谢产物的降解与生态风险

为探讨施用农药毒死蜱后土壤中毒死蜱及其主要降解产物3，5，6-三氯吡啶-2-酚（TCP）污染分布特征，评估农田土壤环境中毒死蜱及TCP的环境风险，以玉米、小麦和大豆3种作物农田为研究对象，开展旱地农田田间试验。通过对施用后不同时间农田土壤中毒死蜱浓度检测发现，土壤中毒死蜱均在前期消解较快，后期逐渐变缓。小麦、大豆、玉米种植土壤中毒死蜱的半衰期为7.86~24.84 d（均小于30 d），消解速率常数为0.027 9~0.088 2 d^-1。前期均表现为0~5 cm土壤中毒死蜱残留量最大，15~20 cm土壤中毒死蜱残留量最小，即随着深度的增加土壤中毒死蜱的残留量逐渐降低；随着时间的延长，0~10 cm土壤中毒死蜱残留量逐渐减少，10~20 cm土壤中毒死蜱残留量逐渐增加。TCP比母体毒死蜱更容易迁移，对环境的污染风险较高。随着毒死蜱施用剂量的增加，小麦、大豆、玉米3种作物种植土壤中毒死蜱及TCP的短期和长期生态风险均增大。超推荐剂量施用毒死蜱导致毒死蜱及TCP产生较高的短期和长期生态风险，TCP生态风险在3种作物农田中均达到了高风险等级。     

皖北石灰岩山地不同植被恢复模式对植物群落物种组成及多样性的影响

通过研究皖北石灰岩山地生态系统的植被群落,分析不同植被恢复群落的组成、结构、多样性和生活型组成,进而阐明石灰岩山地生态系统植被恢复模式对群落结构特征以及植物物种多样性的影响。结果表明:研究区有54种植物,隶属26科54属。侧柏(Platycladus orientalis)+构树(Broussonetia papyrifera)人工混交林有植物种类16科26种,分别占总数的61.5%和48.1%。酸枣(Ziziphus jujuba var.spinosa)+牡荆(Vitex negundo var.cannabifolia)灌丛和荩草(Arthraxon hispidus)+牡荆草灌丛植物种类分别为32和33种,分别占调查总物种数的59.3%和61.1%。不同植被恢复群落生活型也有差异。侧柏+构树人工混交林群落高位芽植物占优势,而酸枣+牡荆灌丛和荩草+牡荆草灌丛则以地面芽植物所占比例较大。分析表明,多样性指数、均匀度指数和优势度指数均表现为侧柏+构树混交林>酸枣+牡荆灌丛>荩草+牡荆草灌丛,但物种丰富度表现为荩草+牡荆草灌丛>酸枣+牡荆灌丛>侧柏+构树混交林。Sörensen较高值出现在酸枣+牡荆灌丛与侧柏+构树混交林和荩草+牡荆草灌丛之间,侧柏+构树混交林与荩草+牡荆草灌丛Sörensen多样性值较低。研究结果表明,石灰岩山地独特的地貌特征和人工植被恢复对植物群落组成、多样性及其生活型组成产生重要影响。     

长江口盐沼湿地鱼类群落优势种的时空生态位特征

为了解长江口盐沼湿地优势鱼类群落结构及其种间关系，采用插网调查，利用2019年5—10月的调查数据，基于生态位宽度和生态位重叠度指数对长江口崇明东滩（31°27''N，121°56''E）和九段沙盐沼湿地（31°10''N，121°57''E）鱼类群落的优势种生态位进行研究。研究结果表明，春、夏、秋3个季节共采获10个优势种，其中鮻（Liza haematocheila）、花鲈（Lateolabrax maculatus）和拉氏狼牙虾虎鱼（Odontamblyopus rubicundus）在3个季节中均为优势种。在10个优势种中，时间生态位宽度值变化范围为0.11~1.70，其中拉氏狼牙虾虎鱼时间生态位宽度值最大，小黄鱼（Larimichthys polyactis）值最小；空间生态位宽度值变化范围为0.57~1.53，其中棱鮻（Liza carinatus）空间生态位宽度值最大，小黄鱼值最小。长江口盐沼湿地鱼类优势种生态位宽度呈现显著的季节性变化趋势。长江口盐沼湿地鱼类优势种的时空生态位重叠值较高，其中具重叠意义的鱼种对（species pairs）高达73.33%，具有显著重叠意义的鱼种对高达48.89%。结论认为，长江口盐沼湿地鱼类优势种的时空分布具有相似性，存在明显的竞争关系。     

施用多功能生态肥对番茄生长和经济效益的影响

为了解决敦煌市蔬菜品质差、产量低而不稳的疑难问题,为温室蔬菜安全生产提供技术支撑,进行了多功能生态肥对番茄生长和效益的研究。结果表明:多功能生态肥原料间的主次效应(R)是:B(番茄专用肥,R=26.92)A(有机生态肥,R=24.29)C(土壤消毒杀菌剂,R=12.55);最佳配方组合是:m(有机生态肥)∶m(番茄专用肥)∶m(土壤消毒杀菌剂)=0.818 6∶0.177 4∶0.004 0。施用多功能生态肥与施用传统化肥比较,番茄早疫病发病率和可滴定酸分别降低66.67%和28.00%;株高、生长速度、茎粗、地上部分鲜质量和地上部分干质量分别增加4.45%、3.81%、7.61%、8.40%和6.67%;单果质量、单株果质量、产量、可溶性糖和VC含量分别增加6.23%、9.26%、8.82%、27.46%和23.65%;施肥利润和肥料投资效率分别增加1.84×10~4元/hm~2和1.23元/元。在甘肃省敦煌市肃州镇的温室土壤上施用多功能生态肥,改善了番茄品质,提高了番茄的经济效益。     

国内土壤环境污染防治进程及展望

综述以中国2005—2019年土壤污染防治进程的3个阶段为主线,总结土壤污染防治发展过程中管理模式、治理体系、管控要求、机构改革、立法支持等5个方面重要转变,分析国家和地方土壤环境保护标准、法律法规政策和主要土壤污染治理成效。针对国内土壤污染防治未来发展趋势,从完善土壤环境标准及管理制度、建设监测及预警大数据平台、加强土壤生态环境国际合作、持续推进土壤修复技术攻关和先行区经验推广等方面提出建议,以期为生态环境高水平保护和经济社会高质量发展提供参考。     

Allochrony as a potential driver for reproductive isolation in adaptive radiations of European whitefish ecomorphs

In northern Fennoscandian lakes, monophylogenetic lineages of postglacial fishes are radiating into several adaptive forms, but the speciation process is still at an incipient stage. The speciation process has received increased attention over the years, but the underlying mechanisms and drivers are still debated and poorly understood. European whitefish (Coregonus lavaretus [L.]) is the most abundant fish species in these lakes and has evolved into several ecomorphs adapted to different trophic niches and habitats. Genetic divergence has been observed among these ecomorphs, but the mechanism(s) responsible for the ongoing build-up of reproductive isolation has still to be revealed. As these systems are young in evolutionary time (<10 kyr), prezygotic and postzygotic extrinsic isolation mechanisms are thought to be more likely to contribute to the reproductive isolation than intrinsic isolation mechanisms. We determined the gonadosomatic index (GSI) of three ecomorphs in two replicated lake systems and used GSI as a proxy to investigate the prezygotic isolation mechanism, allochrony, as a driving factor of divergence in this adaptive radiation of whitefish. We found that the three ecomorphs differed in GSI values within and between lakes, suggesting different spawning times of the ecomorphs. We also show that males of one ecomorph had equal onset of maturity as another ecomorph, giving novel insights into the ongoing gene flow observed between ecomorphs. The result supports allochrony as a driver for the divergence process of whitefish ecomorphs, but more evidence is still needed to rule out that the three ecomorphs make use of different spawning grounds.     

Uncertainty assessment of soya bean yield gaps using DSSAT‐CSM‐CROPGRO‐Soybean calibrated by cultivar maturity groups

Soya bean yield gap can be caused by different factors resulting in uncertainties when the objective is to use such information for farm decision‐making and reference yield determination. Thus, this study aimed to quantify the soya bean yield gap for four sites, located in Southern and Midwestern Brazil, as well as the uncertainties of that related to cultivars, sowing dates, soil types and reference yields. The crop simulation model DSSAT‐CSM‐CROPGRO‐Soybean was calibrated for cultivars with similar maturity groups, based on the data obtained from the best farmers at the county level. The yield gap by water deficit (YG_WD) was obtained through the difference between potential and attainable yields, and that one caused by sub‐optimum crop management (YG_CM) by subtracting actual yield of each county, obtained from official statistics between 1989/90 and 2014/15 growing seasons, from the estimated attainable yield. The yield was simulated using four sowing dates, three soil types and two soya bean maturity groups by county. The reference yield uncertainty was quantified using yield reference from crop model and regional winners of the soya bean yield context, conducted by CESB (Brazilian Soybean Strategic Committee), for the growing seasons from 2013/14 to 2015/16. The crop model showed a good agreement between measured and simulated crop development and growth using calibration by maturity group, with low root mean square error (347 kg/ha). Southern sites had a mean YG_WD of 1,047 kg/ha, while in the Midwest, it was lower than 100 kg/ha. The YG_CM was 1,067, 528, 984 and 848 kg/ha, respectively, for Castro, PR, Mamborê, PR, Montividiu, GO and Primavera do Leste, MT, representing the opportunity for yield gain when having the best farmers as reference. The maturity groups, sowing dates and soil types showed to be an important source of uncertainty for yield gap determination, being recommended to investigate the farms in detail for an appropriate quantification. The reference yield showed expressive uncertainties, with some farmers presenting conditions to increase their soya bean yields by more than 3,000 kg/ha, when considering as reference the yields obtained by the winners’ farmers. These results show that uncertainties must be reduced when assessing farm yield gaps, in order to ensure that expected rate of soya bean yield growth could be reached by adopting the same technologies from CESB winners and best farmers in the county as a reference.     

Quantifying uncertainty in the wild‐caught fisheries goal of the Ocean Health Index

Sustainability indices are proliferating, both to help synthesize scientific understanding and inform policy. However, it remains poorly understood how such indices are affected by underlying assumptions of the data and modelling approaches used to compute indicator values. Here, we focus on one such indicator, the fisheries goal within the Ocean Health Index (OHI), which evaluates the sustainable provision of food from wild fisheries. We quantify uncertainty in the fisheries goal status arising from the (a) approach for estimating missing data (i.e., fish stocks with no status) and (b) reliance on a data‐limited method (catch‐MSY) to estimate stock status (i.e., B/B_MSY). We also compare several other models to estimate B/B_MSY, including an ensemble approach, to determine whether alternative models might reduce uncertainty and bias. We find that the current OHI fisheries goal model results in overly optimistic fisheries goal statuses. Uncertainty and bias can be reduced by (a) using a mean (vs. median) gap‐filling approach to estimate missing stock scores and (b) estimating fisheries status using the central tendency from a simulated distribution of status scores generated by a bootstrap approach that incorporates error in B/B_MSY. This multitiered approach to measure and describe uncertainty improves the transparency and interpretation of the indicator and allows us to better understand uncertainty around our OHI fisheries model and outputs for country‐level interpretation and use.     

The neglected role of religion in fisheries management

Religion and spirituality have long played important roles in fishery systems around the world, and yet are often neglected in modern fisheries management and research. We review current literature and analyse the major small‐scale fishery on Lake Tanganyika, Africa, to highlight how religion may mediate fishing behaviours. Our study surveyed 154 fishers across 11 landing sites in Tanzania, followed by 15 semi‐structured interviews with key informants including fishery officers and local religious leaders. We identified key connections between religious beliefs/practices and fisher perceptions, behaviour and compliance with harvest restrictions and regulations. We demonstrate that better understanding and accounting for religious dimensions is critical for engaging with fishery stakeholders more effectively and managing global fisheries more sustainably.     

Hazards of managing disparate species as a pooled complex: A general problem illustrated by two contrasting examples from Hawaii

Surprisingly little published information exists on the pros and cons of managing extracted resources that are pooled as compound taxa such as species complexes. Current fisheries management includes many species complexes; in Hawaii, this includes two taxa of species pooled at subfamily and higher levels. These include seven species of parrotfishes (Scarinae, Labridae) and a seven‐species ‘bottomfish’ complex (the ‘Deep‐7’: comprising six species of snappers [Etelinae, Lutjanidae] and a single species of grouper [Epinephelidae]). Recent research on key vital rates (growth, reproduction) for major species in both taxa indicates that these complexes consist of species with disparate life histories. Species in the parrotfish taxon exhibit fast to very fast growth and short to moderate longevities, whilst Deep‐7 bottomfishes exhibit moderate to very slow growth and long to very long lifespans. These data clearly indicate that, although pooling species is a tempting default option in data‐poor situations, it is at best a necessary evil to be avoided when sufficient data on the demographics of component species become available. Pooling species is especially problematic when the ecosystem effects of extracting functionally dominant species should be an important management consideration in addition to that of species demographics. Assessments that recognize and quantify the ecosystem importance of habitat engineers and other ecological dominants could substantively improve management of species complexes. Ultimately, complexes of resource species need to be evaluated and managed based on many, sometimes conflicting and sometimes reinforcing, but always careful considerations such as those contrasted herein between the parrotfishes and bottomfishes of Hawaii.