Rapid assessment of insect pollination services to inform decision-making

Pollinator declines have prompted efforts to assess how land-use change affects insect pollinators and pollination services in agricultural landscapes. Yet many tools to measure insect pollination services require substantial landscape-scale data and technical expertise. In expert workshops, 3 straightforward methods (desk-based method, field survey, and empirical manipulation with exclusion experiments) for rapid insect pollination assessment at site scale were developed to provide an adaptable framework that is accessible to nonspecialist with limited resources. These methods were designed for TESSA (Toolkit for Ecosystem Service Site-Based Assessment) and allow comparative assessment of pollination services at a site of conservation interest and in its most plausible alternative state (e.g., converted to agricultural land). We applied the methods at a nature reserve in the United Kingdom to estimate the value of insect pollination services provided by the reserve. The economic value of pollination services provided by the reserve ranged from US$6163 to US$11,546/year. The conversion of the reserve to arable land would provide no insect pollination services and a net annual benefit from insect-pollinated crop production of approximately $1542/year (US$24∙ha^–1∙year^–1). The methods had wide applicability and were readily adapted to different insect-pollinated crops: rape (Brassica napus) and beans (Vicia faba) crops. All methods were rapidly employed under a low budget. The relatively less robust methods that required fewer resources yielded higher estimates of annual insect pollination benefit.     

The physiological response and iron and potassium contents in the hairy roots of Brassica rape L. Under cadmium stress北大核心CSCD

The experiments were conducted to investigate the tolerance and enrichment capabilities by elucidating the physiological response and cadmium impact on iron and potassium accumulation amounts of brassica rape hairy roots under different cadmium concentrations by using liquid suspension culture method. The results showed the following. (1) The growth of hairy roots was not significantly different under low cadmium concentrations (below 100 μmol/L), whereas it was obviously inhibited under high cadmium concentrations (more than 100 μmol/L). Further, the maximum fresh weight of brassica rape hairy roots reached 4.34 g under 25 μmol/L cadmium stress after 7 days. (2) The content of ROS in brassica rape hairy roots increased with increasing concentrations of cadmium; the antioxidant enzyme activities of brassica rape hairy roots (SOD, POD, and CAT) decreased first and then increased with increasing cadmium concentrations under 1-day stress, whereas showed an opposite trend under 7-day stress. (3) PI staining and MDA content indicated that cellular damage was more serious with increasing cadmium concentrations. (4) With the increase of cadmium concentrations, cadmium content of hairy roots increased and reached maximum of 2.97 mg/g under 400 μmol/L cadmium stress after 7 days. The iron content also increased significantly with the maximal weight of 14.52 mg/g after 1-day cadmium stress, whereas no significant difference was noted under 7-day cadmium stress. The potassium content under 7-day cadmium stress was 1.6 times of that after 1-day stress (15.73 mg/g). The study showed that the physiological response of Brassica rape hairy roots was correlated with the concentration and time of cadmium stress. Moreover, cadmium stress caused metabolic disorders of iron and potassium in the hairy roots, but the hairy roots of Brassica rape had better enrichment effect on cadmium. © 2018 Science Press. All rights reserved.     

黄土丘陵沟壑区饲料油菜种植试验及其产业化前景——以延安治沟造地典型项目区为例

沟道土地整治后,如何实现土地的持续、高效利用成为黄土高原丘陵沟壑区面临的突出问题,其关键在于如何充分发挥农牧交错区的比较优势,因地制宜发展种养结合的农业生产模式。依托延安市宝塔区羊圈沟和顾屯沟实验基地,通过大田试验研究了黄土丘陵沟壑区沟道土地整治后种植饲料油菜的技术要点,并探讨了基于饲料油菜种植构建新型农业生产模式的思路。结果表明：1）延安地区具备种植春季饲料油菜的自然生态适宜性,春播饲料油菜播种量以3.9~5.1 kg/hm²为宜,苗期密度宜控制在22.5万株/hm²左右;2）饲料油菜种植需要一定的田间管理,做到施足底肥,适当追肥,间苗遵循“五去五留”原则,4~5片真叶期定苗并适当追肥浇水;3）根据油菜多功能性,黄土丘陵区可发展饲用、菜用+饲用、菜用+观光+油料等多种产品组合模式,科学推广油菜种植可以促进集“种植+养殖+加工+观光”等于一体的多功能农业发展。     

作物幼苗Cd含量标征土壤Cd污染的研究

用盆栽试验,以小麦、大豆和油菜为对象,研究了利用作物幼苗Ｃｄ含量标征土壤Ｃｄ污染的可行性。结果表明,在３种作物生长过程中,幼苗Ｃｄ含量均高于生长后期或可食部分Ｃｄ含量。小麦、大豆籽粒Ｃｄ含量与苗期Ｃｄ含量及土壤Ｃｄ投加量成正相关关系,采收期油菜Ｃｄ含量与苗期Ｃｄ含量成正相关关系。这３种作物的可食部分Ｃｄ含量达到我国食品卫生标准时,小麦三叶期、大豆幼苗地上部分及油菜幼苗的Ｃｄ含量临界值分别为０．７２     

旱三熟带状轮作小春预留行栽油菜技术

本文根据南充地区冬春气候特点,并针对旱地实行的中厢分带间套种植小春预留行未充分利用的状况,从1984年开始在预留行进行了栽油菜研究。结果表明,一般亩增菜籽30～40kg,增加产值34～45元,纯收入21～32元,并找出了适于预留行栽植的油菜品种和配套栽培技术。     

不同臭氧熏气方式对油菜光合速率、生物量和产量的影响

为准确评价臭氧(O3)浓度升高对农作物的影响,运用田间原位开顶气室(open-topchamber,OTC)研究了高浓度O3对油菜光合作用、生物量和产量的影响.实验包括3种O3水平,一种为经活性炭过滤的空气(CF),两种高浓度O3处理:经活性炭过滤后的空气加入恒定浓度为100nL·L-1的O(3CF100);经活性炭过滤后的空气加入具有日变化特征,其平均浓度和剂量与CF100相同的O3(CF100D).结果表明,CF100和CF100D均能使油菜叶片膜透性和H2O2自由基含量增加,光合色素含量和光合速率(photosynthesisrate,Pn)降低,最终导致油菜生物量和产量降低.与CF相比,CF100和CF100D熏气下油菜单位面积产量分别降低3.7%和18.6%.同时,实验还表明,CF100D对油菜的影响大于相同剂量的CF100.以上结果表明:1)高浓度的O(3CF100和CF100D)能够破坏细胞膜系统,减少光合色素数量,降低光合速率,从而降低作物生物量和产量;2)相同平均浓度和剂量的高浓度O3对油菜的影响因熏气方式的不同而有明显差异,目前采用的O3平均浓度和O3剂量指标不能准确评价O3浓度升高对油菜的影响.     

Improving the sustainability of the production of biodiesel from oilseed rape in the UK

Owing to concerns about energy security and because of increased environmental awareness, the biofuel industry is expanding worldwide. It is therefore extremely important to be able to quantify the sustainability of biofuels in order to determine their benefits over using conventional fossil fuel derived transport fuels. This study investigates the total energy requirement and global warming potential (GWP) of the production of biodiesel from oilseed rape in the UK, using life cycle analyses. Large- and small-scale productions are compared and the sensitivity of these environmental impacts to production variables investigated. Possible changes to the processes are considered, with a view to reduce the energy requirement and global warming potential.This research shows that the scale of the production of biodiesel from oilseed rape in the UK, and the transport involved in the various stages of manufacture, has little effect on its global warming potential. It is also shown that if the rape meal and glycerol were combusted in combined heat and power plants, and the rate of application of nitrogenous fertiliser were reduced from 211 kg/ha to 100 kg/ha, the energy requirement and global warming potential savings from using biodiesel rather than ultra low sulphur diesel would increase dramatically, to 170% and 120%, respectively, on a basis of equivalent net energy content.     

Hazard mitigation or mitigation hazard?

BACKGROUND, AIM AND SCOPE: Transgenic oilseed rape (Brassica napus L.; OSR) is estimated to be environmentally and economically problematic because volunteers and ferals occur frequently and because of its hybridisation potential with several wild and weedy species. A proposed mitigation strategy aims to reduce survival, in particular in conventional OSR crops, by coupling the transgenic target modification with a dwarfing gene to reduce competitive fitness. Our study allowed us to access potential ecological implications of this strategy. MATERIALS AND METHODS: On a large scale (>500 km(2)), we recorded phenological and population parameters of oilseed rape plants for several years in rural and urban areas of Northern Germany (Bremen and surroundings). The characterising parameter were analysed for differences between wild and cultivated plants. RESULTS: In rural areas, occurrences of feral and volunteer OSR together had an average density of 1.19 populations per square kilometre, in contrast to urban areas where we found 1.68 feral populations per square kilometre on average. Throughout the survey, the vegetation cover at the locations with feral OSR ranged from less than 10% to 100%. Our investigations gave clear empirical evidence that feral OSR was, on average, at least 41% smaller than cultivated OSR, independent of phenological state after onset of flowering. DISCUSSION: The findings can be interpreted as phenotypic adaptation of feral OSR plants. Therefore, it must be asked whether dwarfing could be interpreted as an improvement of pre-adaptation to feral environments. In most of the sites where feral plants occurred, germination and establishment were in locations with disturbed vegetation cover, allowing initial growth without competition. Unless feral establishment of genetically modified dwarfed traits are specifically studied, it would not be safe to assume that the mitigation strategy of dwarfing also reduces dispersal in feral environments. CONCLUSIONS AND RECOMMENDATIONS: With respect to OSR, we argue that the proposed mitigation approach could increase escape and persistence of transgene varieties rather than reducing them. We conclude that the development of effective hazard mitigation measures in the risk evaluation of genetically modified organisms requires thorough theoretical and empirical ecological analyses rather than assumptions about abstract fitness categories that apply only in parts of the environment where the plant can occur.     

稀土元素La对油菜某些生理指标的影响及其临界浓度

通过水培试验 ,研究了稀土元素La对油菜生物量和叶绿素含量、硝酸还原酶活性、根系活力、POD活性等一系列生理指标的影响。结果表明 :喷施或根施 0 0 3～ 3mg/kg的La3+对油菜的生长起了一定的促进作用 ,表现为生物量、叶绿素含量、硝酸还原酶活性和根系活力增加 ;而高于 3 0mg/kg浓度的La3+对油菜的生长产生了抑制作用 ,油菜生物量、叶绿素含量、硝酸还原酶活性和根系活力降低 ,POD活性增高。La对油菜的临界浓度为 3 0mg/kg。