The land use–climate change–energy nexus

Landscape ecology focuses on the spatial patterns and processes of ecological and human interactions. These patterns and processes are being altered by both changing resource-management practices of humans and changing climate conditions associated, in part, with increases in atmospheric concentrations of greenhouse gases. Dominant resource-extraction and land-management activities involve energy, and the use of fossil energy is one of the key drivers behind increasing greenhouse gas emissions as well as land-use changes. Alternative energy sources (such as wind, solar, nuclear, and bioenergy) are being explored to reduce greenhouse gas emission rates. Yet, energy production, including alternative-energy options, can have a wide range of effects on land productivity, surface cover, albedo, and other factors that affect carbon, water, and energy fluxes and, in turn, climate. Meanwhile, climate influences the potential output, relative efficiencies, and sustainability of alternative energy sources. Thus, land use, climate change, and energy choices are linked, and any comprehensive analysis in landscape ecology that considers one of these factors should be cognizant of these interactions. This analysis explores the implications of linkages between land use, climate hange, and energy and points out ecological patterns and processes that may be affected by their interactions.     

萱草不同品种花瓣挥发性物质的HS–SPME–GC–MS分析

通过顶空固相微萃取(HS–SPME)结合气相色谱—质谱联用(GC–MS)技术,优化萱草品种‘沙曼’花瓣中挥发性成分的最佳萃取温度和萃取时间,形成优化的预处理条件后,对处于同一生境下的9个萱草品种(‘自由行’‘星光玫瑰’‘四十二街’‘乔丹’‘茉莉百合’‘流星’‘幻想之网’‘烈焰’和‘沙曼’)盛花期花瓣中的挥发性成分进行GC–MS检测分析,并辅以气相色谱—质谱—嗅闻联用(GC–MS–O)及香气活性值(OAV)确定关键香气物质。结果表明,‘沙曼’最佳萃取温度为80℃,最佳萃取时间为40 min。在此条件下,9个品种萱草中共检测到197种挥发性成分,包括醇类、萜烯类、醛类、腈类、酚类、酯类、烷烃、呋喃及少量其他物质。通过峰面积归一法结合GC–MS–O,27种挥发性成分被鉴定成为关键香气成分。经主成分分析(PCA)和聚类分析(HCA),认定(Z)-β–罗勒烯和壬醛构建了萱草的主体香气成分,并初步推断反式–橙花叔醇、芳樟醇、苯乙醇、吲哚、草蒿脑等是造成不同品种萱草香气差异的原因。9个萱草样品根据香气特性聚为4组,一组为‘自由行’和‘星光玫瑰’,其不具有苯乙腈、苯乙醇和苯乙醛,显现木香、草香、花香为...     

砀山酥梨和秋白梨酚类物质UPLC–PDA–MS/MS–ESI分析

采用超高效液相色谱—二极管阵列—串联四级杆质谱联用法(UPLC–PDA–MS/MS–ESI)对砀山酥梨和秋白梨果皮、果肉和果心(不含种子)中的酚类物质进行了分析。结果表明,两个品种检出42种酚类组分。大多数酚类物质在果皮中含量最高,仅绿原酸和Z–咖啡酰奎尼酸在果心最高。果皮中的酚类物质种类最多,砀山酥梨果皮中含有5大类42种;秋白梨果皮中含有4大类30种,砀山酥梨比秋白梨多7种黄酮类组分和3种槲皮素糖苷类物质。在果心和果肉中未检出黄烷醇类、黄酮醇类和黄酮类物质。在砀山酥梨果皮中鉴定出其他梨果实中尚未见有报道的芹菜素7–O–芸香糖苷,在砀山酥梨和秋白梨果皮中鉴定出原花青素B1和B2两种原花青素二聚体和原花青素C1及暂命名的C-1、C-2和C-3等4种原花青素三聚体。     

蜡梅科6种植物嫩梢挥发性成分的HS–SPME–GC–MS分析

采用顶空固相微萃取（HS–SPME）与气质联用（GC–MS）分析技术，对蜡梅科6种植物挥发性成分进行检测，并通过共有成分分析、主成分分析、聚类分析，与药用价值较高的山蜡梅主要挥发性成分进行对比。检测结果表明：蜡梅‘鸿运’（Chimonanthus praecox‘Hongyun’）、‘金玉’（Ch. praecox ‘Jinyu’）和‘鄢陵素心’（Ch. praecox‘Yanlingsuxin’），山蜡梅（Ch. nitens）、夏蜡梅（Calycanthus chinensis）及美国蜡梅（Ca. floridus）嫩梢挥发性成分种类分别为47、48、44、44、48和46种，共包含141种成分；蜡梅科6种植物共有挥发性成分以烯烃类、醇类物质为主，‘鸿运’‘金玉’‘鄢陵素心’蜡梅、夏蜡梅和美国蜡梅与山蜡梅共有挥发成分分别为15、18、10、14和20种；PCA分析和聚类分析结果表明：夏蜡梅单独为一类，‘鸿运’‘金玉’‘鄢陵素心’蜡梅为一类，山蜡梅和美国蜡梅为一类；‘鸿运’‘金玉’‘鄢陵素心’蜡梅、夏蜡梅和美国蜡梅与山蜡梅的主要挥发性成分对比分析表明：桉叶油醇、对薄荷–1(7),3–二烯为主要差异成分。以上结果表明，6个蜡梅科植物资源嫩梢挥发性成分组成丰富，但种（品系）间存在一定的差异，均具有较大的药用开发潜力。     

桑树类黄酮3–O–葡萄糖基转移酶基因的鉴定及主效基因功能分析

根据同源比对,从川桑(Morus notabilis)基因组数据库(morus.swu.edu.cn/morusdb/)中鉴定类黄酮3–O–葡萄糖基转移酶基因(MaUFGT)家族成员。采用实时荧光定量PCR(q RT-PCR)分析MaUFGT在桑树各组织和发育期的表达水平。随着果实发育成熟,MaUFGT1、MaUFGT2和MaUFGT3的表达模式相似,均呈上升趋势;在从顶芽依次向下不同叶位中,3个UFGT基因表达呈现先降低后升高,再降低又升高的趋势;在幼茎皮层和托叶中大量表达,幼茎表皮和木质部、叶柄中表达量较低,有的甚至不表达。MaUFGT2的表达量在3个基因中都是最高的,推测其是该基因家族的主效基因。从桑树品种‘嘉陵40’成熟果实中克隆了UFGT2基因,命名为MaUFGT2,登录号KP455729.1。其c DNA全长为1 386 bp,编码461个氨基酸,推测蛋白质分子量约为51 k D。序列比对结果发现所编码蛋白在不同物种间保守性不高。将MaUFGT2克隆到p ET-28a(+)原核表达载体后在大肠杆菌BL21(DE3)中进行诱导表达,表达产物经SDS-PAGE分析显示,融合蛋白大小约为55 k D,主要以包涵体形式表达,在上清液中也有少量表达。MaUFGT2蛋白经纯化和复性后,最后通过高效液相色谱(HPLC)分析该蛋白的酶活性,结果表明,体外酶活性鉴定MaUFGT2能够催化UDP葡萄糖转移至槲皮素形成槲皮素3–β–D–葡萄糖苷,验证了其具有糖基转移酶的功能。     

草莓9–顺式–环氧类胡萝卜素双加氧酶基因FaNCED的克隆及表达分析

 采用RT-PCR和RACE技术从草莓果实中克隆ABA合成途径中关键基因FaNCED,该cDNA全长2 228 bp,具有完整的开放阅读框（ORF）,共1 827个碱基,编码609个氨基酸。序列分析表明,FaNCED编码的氨基酸序列与其他植物的NCED蛋白有很高的同源性。系统进化树分析显示,草莓NCED与同为蔷薇科的湖北海棠聚为一类,与橙、柠檬、温州蜜柚、葡萄等非跃变型果实NCED蛋白亲缘关系较近。实时荧光定量PCR分析发现,FaNCED基因在草莓根、茎、叶、花萼和果实中都有表达;在果实成熟过程中FaNCED的表达出现两次高峰,分别在大白果期和红果期,且在红果期表达量最高,并与ABA积累相吻合;FaNCED在果实采后1 d表达略有下降,之后急剧上升,ABA含量变化与FaNCED基因的表达基本一致。FaNCED可能参与调控ABA的合成并在草莓成熟中起一定作用。     

Abundance–occupancy and abundance–body mass relationships of small mammals in a mountainous landscape

Context

Mountainous landscapes are characterized by strong spatial heterogeneity, leading to increasing geographical isolation and decreasing area with elevation. Consequently, the colonization rate decreases from the low to high elevation zone, while the extinction rate shows the opposite.

Objectives

Due to such changes, we test whether (1) species occur at a declining number of sites (mountains) and have a less positive abundance–occupancy relationship (AOR) in a higher elevation zone; (2) a lower proportion of rare large-bodied species (less resistant to extinction) and a more positive abundance–body mass relationship (ABR) emerge in a higher elevation zone.

Methods

Using the data of small mammals from 20 elevational gradients in the Mountainous Region of Southwest China, we compared the AORs and ABRs among the low, middle and high elevation zones. The AOR and ABR were fitted with linear and polynomial regression models. We compared endemic ratios among the different elevation zones.

Results

The AOR was best characterized by a linear model and positive in all elevation zones. Its slope decreased from the low to high elevation zone. The quadratic model performed the best in fitting the ABR in each zone. When fitted with linear models, both the R² and slope of the ABR increased towards the high elevation zone. The endemic ratios were significantly higher in the middle and high elevation zones.

Conclusions

Both the AOR and ABR in mountainous landscapes are strongly elevation-dependent. The increasing geographical isolation and decreasing area with elevation can have a high impact on macroecological patterns and processes.

     

大球盖菇–玉米轮作栽培技术

总结大球盖菇–玉米轮作栽培技术,涵盖大球盖菇栽培的栽培时间、原料准备、铺料播种、发菌期管理、出菇期管理和采收;玉米栽培的茬口安排、品种选择、科学施肥、病虫害防治和适时收获。采用这一技术可利用70%玉米秸秆、30%稻草作为生产大球盖菇培养料;而大球盖菇栽培后的菌渣直接还田作为有机肥种植玉米,具有生产成本低、操作技术简便和生态环保的优点。     

Diversity–disturbance relationship in forest landscapes

Context

Despite decades of research, there is an intense debate about the consistency of the hump-shaped pattern describing the relationship between diversity and disturbance as predicted by the intermediate disturbance hypothesis (IDH). Previous meta-analyses have not explicitly considered interactive effects of disturbance frequency and intensity of disturbance on plant species diversity in terrestrial landscapes.

Objective

We conducted meta-analyses to test the applicability of IDH by simultaneously examining the relationship between species richness, disturbance frequency (quantified as time since last disturbance as originally proposed) and intensity of disturbance in forest landscapes.

Methods

The effects of disturbance frequency, intensity, and their interaction on species richness was evaluated using a mixed-effects model.

Results

We found that species richness peaks at intermediate frequency after both high and intermediate disturbance intensities, but the richness-frequency relationship differed between intensity classes.

Conclusions

Our study highlights the need to measure multiple disturbance components that could help reconcile conflicting empirical results on the effect of disturbance on plant species diversity.

     

A model of the science–practice–policy interface in participatory land-use planning: lessons from Laos

An essential task of participatory action-research is to help close the policy implementation gap that leads to large discrepancies between policy frameworks and local practices. Too often, official regulations, laws and decrees fail to translate into concrete action on the ground. Loose institutional linkages between research, extension and local communities are often blamed as the main culprits for this gap. In turn, many stakeholders call for enhanced participation as a way to bring together scientists, development practitioners and local communities in negotiating competing claims for natural resources and designing realistic pathways towards sustainable development. Despite such general consensus about the value of participation, the latter cannot be decreed nor imposed. Participation is an emerging quality of collective-action and social-learning processes. In this paper, the experience of participatory land-use planning conducted in Laos serves to illustrate a model of the science–practice–policy interface that was developed to facilitate the interactions between three groups of stakeholders, i.e. scientists, planners and villagers, in designing future landscapes. Emphasis was put on developing an approach that is generic and adaptive enough to be applied nationally while engaging local communities in context-sensitive negotiations. The set of tools and methods developed through action-research contributed to enhanced communication and participation from initial consultation and cooperation stages towards collective decision-making and action. Both the activity of landscape design and the resulting patterns can be improved by incorporating landscape science in strategic multi-stakeholder negotiations.     

Landscape connectivity and predator–prey population dynamics

Landscapes are increasingly fragmented, and conservation programs have started to look at network approaches for maintaining populations at a larger scale. We present an agent-based model of predator–prey dynamics where the agents (i.e. the individuals of either the predator or prey population) are able to move between different patches in a landscaped network. We then analyze population level and coexistence probability given node-centrality measures that characterize specific patches. We show that both predator and prey species benefit from living in globally well-connected patches (i.e. with high closeness centrality). However, the maximum number of prey species is reached, on average, at lower closeness centrality levels than for predator species. Hence, prey species benefit from constraints imposed on species movement in fragmented landscapes since they can reproduce with a lesser risk of predation, and their need for using anti-predatory strategies decreases.     

Alternative stable states and the role of fire–vegetation–soil feedbacks in the temperate wilderness of southwest Tasmania

Two ecological models have been put forward to explain the dynamics of fire-promoting and fire-sensitive vegetation in southwest Tasmania: the alternative stable states model of Jackson (in Proc Ecol Soc Aust 3:9–16, 1968) and the sharpening switch model of Mount (in Search 10:180–186, 1979). Assessing the efficacy of these models requires high resolution spatio-temporal data on whether vegetation patterns are stable or dynamic across landscapes. We analysed ortho-rectified sequences of aerial photography and satellite imagery from 1948, 1988 and 2010 to detect decadal scale changes in forest and non-forest vegetation cover in southwest Tasmania. There was negligible change from forest to non-forest (<0.05%) and only a modest change from non-forest to forest over the study period. Forest cover increased by 4.1% between 1948 and 1988, apparently due to the recovery of forest vegetation following stand-replacing fire prior to 1948. Forest cover increased by 0.8% between 1988 and 2010, reflecting the limited ability of forest to invade treeless areas. The two models include interactions between vegetation, fire and soil, which we investigated by analysing the chemical (phosphorus, nitrogen) and physical properties (clay, silt) of 128 soil samples collected across 34 forest–non-forest boundaries. Phosphorus in the upper horizon was typically lower in non-forest vegetation compared to forest vegetation, which is consistent with proposed fire–vegetation–soil feedbacks. Mineral horizons were dominated by sand, with low levels of clay under all vegetation types. Available field evidence lends support to the Jackson (1968) alternative stable states model as the most suitable model of vegetation dynamics on nutrient poor substrates in southwest Tasmania although modifications of the timeframes for transitions toward rainforest are required.     

衍生化结合分散固相萃取–UPLC–MS/MS法测定果品中EBDCs类农药残留

建立了果品中乙撑双二硫代氨基甲酸酯(盐)类(简称EBDCs)残留的液质串联确证快速检测方法。果品样品中的EBDCs经碘甲烷甲基衍生化后用分散固相萃取(QuEChERS)提取和净化,利用超高效液相色谱—串联质谱(UPLC–MS/MS)在多反应离子监测模式下进行检测,采用基质匹配标准曲线校正,外标法定量。以碎片离子对m/z 241.1/117.1、m/z 241.1/193.0进行定性分析、m/z 241.1/134.0进行定量分析。结果表明,代森锌、代森锰、代森锰锌、代森钠和代森联的甲基化衍生产物亚乙基–1,2–双二硫代氨基甲酸甲酯在不同水果中具有不同的基质效应;在0.005~1.000 mg·kg~(-1)(以二硫化碳计)之间具有良好的线性关系,相关系数为0.9948~0.9996。在苹果、桃、葡萄、柑橘和香蕉果实样品中添加不同水平乙撑双二硫代氨基甲酸酯(盐)时,回收率为82.6%~98.8%,相对标准偏差为0.7%~8.8%。本方法的检出限(以CS2计)为0.6~1.0μg·kg~(-1),定量限(以CS2计)为10μg·kg~(-1)。本方法简便、快速、准确,可用于果品中乙撑双二硫代氨基甲酸酯(盐)的残留确证检测。     

植物类黄酮生物合成相关UDP–糖基转移酶研究进展

类黄酮是人类膳食和观赏园艺植物中重要的多酚类物质,因其广泛的生物活性及重要的生物学功能而倍受关注。植物尿苷二磷酸糖基转移酶(Uridine diphosphateglycosyltransferase,UGT)催化类黄酮生物合成的最后一步从而形成多种多样的糖苷衍生物。近年来,大量UGT基因家族被分析,类黄酮合成相关糖基转移酶也陆续被鉴别报道。本文综述了植物类黄酮生物合成相关UGT的生物化学及分子生物学研究进展,重点对参与不同类黄酮糖基化的UGT体外重组蛋白活性及转基因功能分析等试验证据进行归纳,并介绍了相关的微生物工程,以期为植物类黄酮代谢和其调控原理及生物技术研究提供参考。     

1–甲基环丙烯对番茄冷害的影响

 为探讨1–甲基环丙烯（1-MCP）处理对番茄果实低温贮藏期间冷害和抗病性的影响,以绿熟期的‘浙杂205’番茄为试材,用1 μL · L-1的1-MCP在20 ℃下处理番茄果实6 h,然后将其置于3 ℃冷藏14 d后转入20 ℃后熟16 d。结果发现,1-MCP处理加重了冷藏番茄后熟期间的冷害,但是延缓了硬度和可滴定酸度的下降,推迟了番茄红素的增加和乙烯峰的出现,诱导了多酚氧化酶和过氧化物酶活性,同时降低了几丁质酶和β–1,3–葡聚糖酶的活性。虽然1 μL · L-1的1-MCP处理延缓了冷藏番茄果实的后熟,却加重了番茄后熟期间冷害和病害的发生,不适合在番茄冷藏中应用。     

Towards an energy–landscape integrated analysis? Exploring the links between socio-metabolic disturbance and landscape ecology performance (Mallorca,Spain, 1956–2011)

Context

The role of agricultural landscapes in biodiversity conservation is an emerging topic in a world experiencing a worrying decrease of species richness. Farm systems may either decrease or increase biological diversity, depending on land-use intensities and management.

Objectives

We present an intermediate disturbance-complexity model (IDC) of cultural landscapes aimed at assessing how different levels of anthropogenic disturbance on ecosystems affect the capacity to host biodiversity depending on the land matrix heterogeneity. It is applied to the Mallorca Island, amidst the Mediterranean biodiversity hotspot.

Methods

The model uses the disturbance exerted when farmers alter the Net Primary Production through land-use change as well as when they remove a share of it (HANPP), together with Shannon–Wiener index (H′) of land-cover diversity. The model is tested with a twofold-scalar experimental design (1:50,000 and 1:5000) of a set of landscape units along three time points (1956, 1989, 2011). Species richness of breeding and wintering birds, taken as a biodiversity proxy, is used in an exploratory factor analysis.

Results

The results clearly show that when intermediate levels of HANPP are performed within intermediate levels of complexity (H′) in landscape patterns, like agro-forest mosaics, great bird species richness and high socio-ecological resilience can be maintained. Yet, these complex-heterogeneous landscapes are currently vanishing due to industrial farm intensification, rural abandonment and urban sprawl.

Conclusions

The results make apparent the usefulness of transferring the concept of intermediate disturbance-complexity interplay to cultural landscapes. Our spatial-explicit IDC model can be used as a tool for strategic environmental assessment of land-use planning.