拉丁美洲和加勒比地区主要竹种资源与利用

拉丁美洲和加勒比地区是世界主要的竹资源分布区,以瓜多竹为代表的560多竹种资源占全球竹种的33%,其中巴西、哥伦比亚、秘鲁、厄瓜多尔、墨西哥等国竹林面积和竹种数量位居该地区前列。与亚洲相比,拉丁美洲和加勒比地区现代竹产业发展起步较晚,规模和效益有限。面向未来,该区竹资源主要分布国家的政府正在制定和实施相关政策和战略,助力竹区发展经济、缓解贫困和保护环境。     

木麻黄与根系微生物关系研究进展

木麻黄是我国沿海防护林基干林带中的主栽树种,与土壤中的微生物可以形成共生关系,提高自身耐干旱、抗贫瘠、抗盐碱等适应恶劣环境的能力。土壤中的细菌和真菌能够与木麻黄根系形成稳定的相互作用的微生态系统,其中微生物主导的物质代谢循环是植物获取营养的主要来源之一,反之木麻黄的根系分泌物可以为微生物的生长提供养分。文中综述了木麻黄与根系微生物之间相互作用的相关研究,尤其是接种弗兰克氏菌（Frankia）及菌根菌提高木麻黄抗逆性方面的研究进展,对木麻黄与根系微生物体系的促生、抗逆机制进行了探讨和展望。     

夹竹桃花挥发油的GC-MS分析及β-葡萄糖苷酶对夹竹桃花的增香和豚鼠离体子宫平滑肌的作用

目的:建立夹竹桃花挥发油GC-MS的色谱分离鉴定方法,分析夹竹桃花挥发油的化学成分和对豚鼠离体子宫平滑肌的作用。方法:采用挥发油提取器提取夹竹桃花挥发油,以GC-MS法进行分析鉴定,建立了豚鼠离体子宫模型。结果:分别从无酶和有酶的夹竹桃花挥发油提取物中确证了58和57个化合物,挥发油对豚鼠离体子宫平滑肌有收缩作用。结论:对夹竹桃的挥发油化学成分进行了比较分析结果表明,β-葡萄糖苷酶对夹竹桃花有较弱增香作用,也能增加豚鼠离体子宫平滑肌收缩。     

Effect of humic acid on the sedimentation and transport of nanoparticles silica in water-saturated porous media

Journal of Soils and Sediments - Nano silicon particles (nSiO2) is one of the most widely used industrial engineered nanomaterials (ENMs). The extensive applications of nSiO2 may pose potential...     

Electrokinetic-enhanced remediation of actual arsenic-contaminated soils with approaching cathode and Fe0 permeable reactive barrier

Purpose

The aim of this study was to investigate the remediation efficiency of actual arsenic-contaminated soils by electrokinetic (EK)-enhanced remediation with approaching cathode and Fe⁰ permeable reactive barrier (PRB).

Materials and methods

Experiments were conducted in a lab-made apparatus consisting of the anode reservoir, the soil specimen chamber, and the cathode reservoir.

Results and discussion

In this study, the enhanced combination methods (approaching cathode and Fe⁰-PRB) were assisted for EK remediation of actual arsenic-contaminated soils under a voltage gradient of 1 V/cm and a treatment period of 96 h. Experimental results showed that arsenic accumulated in the anode sections (I, II) of the soil by employing EK alone with an arsenic removal rate of less than 5%. In contrast, EK-enhanced remediation with either approaching cathode (EK/AC) or Fe⁰-PRB (EK/PRB) reduced the arsenic concentrations in both central and anode sections of the soil and afforded the removal rates of 20% in both cases. However, EK-enhanced remediation with the combination of approaching cathode and Fe⁰-PRB (EK/PRB/AC) reached the removal efficiency of 45% without arsenic accumulation in any soil sections. This phenomenon is mainly caused by the approaching cathode that creates an alkaline environment to promote the migration of arsenic, as well as PRB filled with Fe⁰ that achieves the adsorption and immobilization of arsenic.

Conclusions

The highest remediation efficiency was achieved in the EK/PRB/AC test, which was attributed to the fact that the combination of this two methods solved the problem of arsenic accumulation in treated soil and ensured a more thorough arsenic removal. Furthermore, enhanced remediation efficiency does not elevate the costs.

     

Biocrusts resist runoff erosion through direct physical protection and indirect modification of soil properties

Purpose

Biological soil crusts (biocrusts) are ubiquitous in arid and semi-arid regions and play many critical roles in soil stabilization and erosion prevention, greatly decreasing soil loss. Although sediments may be completely controlled by well-developed biocrusts, runoff loss is observed. Consequently, it is important to study how biocrusts resist runoff erosion in different developmental stages to evaluate and manage water erosion.

Materials and methods

In the Loess Plateau Region, we sampled 32 biocrust plots representing eight stages of biocrust development and 5 slope cropland soil plots as bare soil control plots. We then used a rectangular open channel hydraulic flume to test the effects of biocrust development on runoff erosion.

Results and discussion

As expected, the establishment of biocrusts enhanced soil stability, and accordingly, soil anti-scourability significantly increased with biocrust development. Biocrusts exhibiting more than 36% or 1.22 g dm^?2 of moss coverage or biomass fully protected the soil from runoff erosion. Moreover, soil properties, such as soil organic matter, soil cohesion and soil bulk density, were also important in reducing erosion. The findings indicated that biocrusts inhibited runoff erosion through direct physical protection related to biocrust cover and biomass and through the indirect modification of soil properties. In the early biocrust development stage (when moss cover was less than 36%), cyanobacterial biocrust played a primary role in providing resistance to runoff erosion, with resistance being positively related to cyanobacterial biomass (chlorophyll a) and influenced by soil properties.

Conclusions

The relationship between soil anti-scourability and moss coverage or biomass can be divided into two stages based on a moss cover or biomass threshold. The capacity of biocrusts to resist runoff erosion was limited when moss cover was below the threshold value. Therefore, the stage corresponding to this level of moss cover should be of concern when estimating, predicting and managing water erosion.

     

Assessment of soil aggregation properties after conversion from rice to greenhouse organic cultivation on SOC controlling mechanism

Journal of Soils and Sediments - Organic manure is beneficial for macro-aggregate formation and soil organic carbon (SOC), but how SOC change in aggregate fractions in time-series is still...     

Global Dryland Ecosystem Programme (Global-DEP): Australasian consultation report

Journal of Soils and Sediments -     

基于SEPLS模型的GIAHS恢复力评估框架及其在保护成效评估中的应用

由联合国粮农组织认定的全球重要农业文化遗产(GIAHS)是一类典型的社会生态生产景观(SEPLS),在传统知识传承保护、粮食与食物安全保障、农业生物多样性保护、气候变化应对等诸多方面具有重要意义。为了更好、更有效地开展GIAHS保护及管理工作,本文在分析GIAHS评估重要性和恢复力概念的基础上,以联合国大学(UNU)等团队开发的社会生态生产景观恢复力评估框架(SEPLS模型)为基础,构建了GIAHS恢复力评估框架(GIAHS-RAF),明确了其评估及计算过程。并以中国第1个GIAHS项目——浙江青田稻鱼共生系统(Qingtian Rice-Fish Culture System in Zhejiang Province, RFC)为例,通过对核心保护区——龙现村在2004年(GIAHS项目授牌前)和2016年(GIAHS授牌11年)的恢复力状况进行评估,探讨模型在GIAHS保护成效评估中的适用性。研究结果显示:1)2016年龙现村恢复力整体状况相对较弱,各项资本评估得分为:物质资本(0.75)经济资本(0.63)人类资本(0.61)社会资本(0.57)自然资本(0.38);2)虽然农户收入来源多样且社会经济基础设施能较好地满足社区需求,但是遗产地内部农业物种较少,农户对于系统提供的粮食多样性尚不是非常满意; 3)相较于2004年,经过11年的保护工作,研究区恢复力有所提高,说明GIAHS项目的实施对该遗产的恢复力有积极影响,尤其是物质资本和经济资本两方面。评估结果与该区域相关研究结果及实地调查情况一致,说明所构建的GIAHS恢复力评估框架可以很好地应用于对GIAHS项目及其他相关农业文化遗产的保护成效评估工作。     

山葡萄VaCIPK18原核表达与多克隆抗体制备

类钙调磷酸酶B亚基蛋白(CBLs)互作蛋白(CIPKs) 作为类丝氨酸/苏氨酸蛋白激酶,在植物响应非生物胁迫信号转导中起着重要作用。基于前期山葡萄响应低温胁迫转录组测序结果,发现低温胁迫引发的早期伤害及感知阶段的激酶基因中涉及CBL-CIPK 信号通路的VaCIPK18表达显著上调。为进一步研究山葡萄(Vitis amurensis)VaCIPK18激酶参与低温胁迫的功能,采用同源克隆获得了VaCIPK18基因,其开放阅读框为1 320 bp,编码439个氨基酸。基于对VaCIPK18蛋白生物信息学分析,获取胞外结构域中抗原表位丰富的肽段,并将其C端调控结构域(230~439 aa)构建到原核表达载体pET28a-SUMO。将重组表达载体转化至大肠杆菌(E. coli Rosetta)中,经0.8 mmol·L^-1 IPTG、37℃诱导4 h表达出大小为42 kDa的包涵体蛋白。将重组蛋白作为抗原免疫日本大耳白兔,获得anti-VaCIPK18多克隆抗体,经检测具有高效价及特异性。Western Blot结果表明,该抗体可以与葡萄内源CIPK18特异性结合,且在50 kDa位置出现与预期一致的条带。同时,CIPK18在低温胁迫后葡萄叶片中蛋白表达水平与室温下相一致,但两种状态下均存在可能的磷酸化与泛素化修饰现象。本研究结果为进一步探究VaCIPK18的蛋白定位、表达及其功能奠定了基础。