个体-家庭地方认同迭代的生命历程空间叙事

在现代性构建和人的城镇化社会进程推动下,地方认同在发生转换和迭代的变化。与静态视角下地方认同的断面研究不同,论文基于生命历程和家的流动性的动态研究视角,以具有70 a时间跨度的个体-家庭为研究主体,对其地方认同随时空迁移的变化和社会意义进行了生活史式的跟踪解读。研究发现：在城乡迁移过程中,随着时空的转移和生活经历的层累,个体-家庭的地方认同发生了转换、迭代的动态变化。① 这一动态变化与家的流动紧密联系在一起,流动中个体与家庭成员在不同生活区域的地方性产生了地方阻力与地方推力,二者综合作用的结果使得地方认同发生了迭代变化;② 社会环境与社会场景、家庭角色、文化适应与个体行为调整是人的城镇化过程中地方认同迭代的重要影响因素;③ 家庭类型变化和代际差异会影响到地方认同迭代发生的幅度。     

供给侧改革与科技创新耦合助推西藏渔业资源养护

由于西藏生态环境脆弱、生态系统结构简单、生产力低下以及高原鱼类生长缓慢、资源补充周期长、对生境高度适应和依赖等特点,高原水域水生生态更容易受到外界的影响.尤其近几十年以来,外来鱼类入侵、水电水利设施的兴建、过度捕捞、水质环境恶化,导致162种青藏高原鱼类中,处于极危、濒危、易危或野外绝灭鱼类就有35种,超过了20%,在雅鲁藏布江中游,常见的6种裂腹鱼类中,有3种鱼类处于濒危状态,因此推动西藏渔业资源养护刻不容缓.供给侧改革和科技创新,将为西藏渔业资源养护注入新的活力.通过科学引导放生行为,规范和加强增殖放流行为,积累和推广本土鱼类繁育技术,密切关注西藏水生态系统,将会推动西藏渔业资源养护工作迈上一个新台阶,也会助推西藏"精准扶贫"进程.     

福建主要港口外轮压舱水生物的分布及其潜在入侵威胁

根据2006～2007年间采自福建省4个主要港口12艘外轮(包括8条集装箱船和4条散货船)的压舱水样品,研究压舱水生物的分布特点,结果表明进入该水域的外来船舶压舱水生物物种丰富度和个体丰度高,共发现浮游植物7门86属240种(包括60种赤潮生物)和浮游动物5门30属52种;经3种网目(20,77,和160μm)筛网收集的不同粒径生物的平均丰度分别为:动物38858.3 ind./m~3(粒径77～160μm)和782.3 ind./m~3(粒径>160μm);植物3625.0 cells./ dm~3(粒径20～77μm)和134.1 cells./dm~3(粒径77～160μm).压舱水生物的分布及生存状态与水样的盐度及水龄相关.初步评估外来压舱水生物排放对福建沿海的潜在入侵风险.     

Propagating uncertainty from catchment experiments to estimates of streamflow reduction by invasive alien plants in southwestern South Africa

Long-term catchment experiments from South Africa have demonstrated that afforestation of grasslands and shrublands significantly reduces surface-water runoff. These results have guided the country's forestry policy and the implementation of a national Invasive Alien Plant (IAP) control programme for the past few decades. Unfortunately, woody IAP densities continue to increase, compounding existing threats to water security from population growth and climatic change. Decision makers need defensible estimates of the impacts of afforestation or invasions on runoff to weigh up alternative land use options, or guide investment of limited resources into ecosystem restoration through IAP clearing versus engineering-based water-augmentation schemes. Existing attempts to extrapolate the impacts observed in catchment afforestation experiments to broad-scale IAP impacts give no indication of uncertainty. Globally, the uncertainty inherent in the results from paired-catchment experiments is seldom propagated into subsequent analyses making use of these data. We present a fully reproducible Bayesian model that propagates uncertainty from input data to final estimates of changes in streamflow when extrapolating from catchment experiments to broader landscapes. We apply our model to South Africa's catchment experiment data, estimating streamflow losses to plantations and analogous plant invasions in the catchments of southwestern South Africa, including uncertainty. We estimate that regional streamflow is reduced by 304 million m³ or 4.14% annually as a result of IAPs, with an upper estimate of 408 million m³ (5.54%) and a lower estimate of 267 million m³ (3.63%). Our model quantifies uncertainty associated with all parameters and their contribution to overall uncertainty, helping guide future research needs. Acknowledging and quantifying inherent uncertainty enables more defensible decisions regarding water resource management.     

Functional changes due to invasive species: Food web shifts at shallow Posidonia oceanica seagrass beds colonized by the alien macroalga Caulerpa racemosa

Multiple stable isotope analyses were used to examine the trophic shifts at faunal assemblages within the invading macroalga Caulerpa racemosa in comparison to established communities of Posidonia oceanica seagrass meadows. Sampling of macrobenthic invertebrates and their potential food sources of algal mats and seagrass meadows in Mallorca (NW Mediterranean) showed differences in species composition of faunal and primary producers among seagrass and C. racemosa. Accordingly, changes in food web structure and trophic guilds were observed, not only at species level but also at community level. The carbon and nitrogen isotope signatures of herbivores, detritivores and deposit feeders confirmed that the seagrass provided a small contribution to the macrofaunal organisms. δ¹³C at the P. oceanica seagrass and at the C. racemosa assemblages differed, ranging from −6.19 to −21.20‰ and −2.67 to −31.41‰, respectively. δ¹⁵N at the Caulerpa mats was lower (ranging from 2.64 to 10.45‰) than that at the seagrass meadows (3.51–12. 94‰). Significant differences in isotopic signatures and trophic level among trophic guilds at P. oceanica and C. racemosa were found. N fractionation at trophic guild level considerable differed between seagrass and macroalgae mats, especially for detritivores, deposit feeders, and herbivores. Filter feeders slightly differed with a relatively lower N signal at the seagrass and CR values at community level and at trophic guild level were higher in the C. racemosa invaded habitats indicating an increase in diversity of basal resource pools. C. racemosa did seem to broaden the niche diversity of the P. oceanica meadows it colonised at the base of the food web, may be due to the establishment of a new basal resource. The extent of the effects of invasive species on ecosystem functioning is a fundamental issue in conservation ecology. The observed changes in invertebrate and macrophytic composition, stable isotope signatures of concomitant species and consequent trophic guild and niche breadth shifts at invaded Caulerpa beds increase our understanding of the seagrass systems.     

中国东南沿海港口外轮压舱水生物的调查

随机选取东南沿海港口的17艘外来船舶(含8条集装箱船和9条散货船)作为监测对象,进行压舱水浮游植物及动物的物种鉴定和丰度测定,并对监测数据进行统计学分析.检出分属于7个浮游植物门类和5个动物门类的309种外来压舱水生物(包括60种赤潮生物).外轮压舱水生物的分布及生存状态与水样的水龄和盐度相关.船舶压舱水排放是大家熟知...     

苏北滨海湿地互花米草两种繁殖体与本地种竞争能力分析

在碱蓬滩选取互花米草斑块,由外向内分为外围(A)、外侧(B)、内侧(C)、中心(D)四个取样点,研究互花米草实生苗、分蘖苗与本地植物碱蓬、芦苇的相对竞争力,探讨互花米草在碱蓬滩地入侵扩张的趋势。结果表明:1)在斑块B点处,互花米草实生苗与碱蓬相对竞争力高于互花米草分蘖苗与碱蓬相对竞争力;在斑块C点处,互花米草实生苗与碱蓬相对竞争力低于互花米草分蘖苗与碱蓬相对竞争力;多样性指数分析表现为:B点>C点>A点>D点;在互花米草斑块B点处重要值大小表现为:互花米草实生苗>碱蓬>芦苇实生苗>互花米草分蘖苗,在互花米草斑块C点处重要值大小表现为:互花米草分蘖苗>芦苇实生苗>互花米草实生苗>碱蓬。因此,碱蓬滩互花米草斑块主要是通过实生苗入侵新生境,向外扩张,通过互花米草分蘖苗维持种群的稳定。2)在斑块B点,芦苇实生苗与互花米草实生苗的相对竞争力相当,大于互花米草分蘖苗的相对竞争力,但在斑块C点处,互花米草分蘖苗高于芦苇实生苗。碱蓬与本地种芦苇也产生了竞争关系,并很有可能被芦苇和互花米草共同取代。3)互花米草实生苗与碱蓬的相对竞争力与滩涂微生境土壤含水量、土壤全盐量负相关(P<0.01),与土壤pH正相关(P<0.01);互花米草分蘖苗与碱蓬的相对竞争力与土壤含水量、土壤全盐量正相关(P<0.05),与土壤pH负相关(P<0.01)。碱蓬滩斑块处的含水量、盐度适合互花米草的定居、扩张。     

岩溶区土著植物黄荆条和红背山麻杆水浸提液对入侵植物飞机草萌发的影响

黄荆条和红背山麻杆是广西岩溶地区常见的土著植物,在这两种土著植物较多的群落中,飞机草的入侵受到影响。本文通过分析发芽率、发芽速率和化感效应敏感指数等指标,研究了黄荆条和红背山麻杆的根、茎、叶三个部位不同浓度的水提液对飞机草种子萌发的影响,以检验这两种土著植物是否对飞机草具有化感作用。结果表明,与对照相比,红背山麻杆各部位不同浓度的水提液以及黄荆条的根、茎不同浓度的水提液对飞机草种子萌发有微弱的影响,整体表现出低促高抑的现象; 但黄荆条的叶原液对飞机草种子萌发抑制作用显著,在黄荆条叶原液处理下,飞机草发芽率仅为对照的20. 75% ,化感效应敏感指数为- 3. 8191。从生态效益和经济效益考虑,黄荆条可作为岩溶地区生物替代防治飞机草的优选植物。      

厦门马銮湾外来物种沙筛贝对浮游植物的影响

分析了厦门马銮湾外来物种沙筛贝Mgtilopsis sallei入侵5年(1992—1996年)的3次海洋生态学调查资料,并整合近年来的有关资料作综合分析。结果表明,沙筛贝对浮游植物数量时空分布及该湾生态系产生了较大影响:沙筛贝入侵前,由于该湾富营养化逐年加重,浮游植物的丰度达到发生赤潮的数量级(1 000.0个.m-3),第Ⅰ、Ⅱ次网采样品密度分别为21 386×104和110 138×104个.m-3,增幅达5倍,浮游植物的优势种以耐污种优美伪菱形藻Pseuo-Nitzschi a delicatissima占绝对优势,群落的多样性指数下降到富营养化的阈值水平(H=1.0);但自1995年外来物种沙筛贝大量繁殖后,浮游植物的丰度稳定在同一数量级,第Ⅱ、Ⅲ次水采样品密度分别为1150.7和1 300个.cm-3,浮游植物的群落结构也发生了变异,厦门海区常见种尖刺伪菱形藻Pseuo-Nitzschiapungens和中肋骨条藻Skeletonema costatum被取而代之,群落的多样性指数上升到1.29。     

Spatial patterns of epifaunal communities in San Francisco Bay eelgrass (Zostera marina) beds

Epifaunal invertebrate species, such as amphipods and isopods, have been shown to play key but varying roles in the functioning of seagrass habitats. In this study, we characterized patterns in the poorly known epifaunal communities in eelgrass (Zostera marina) beds in San Francisco Bay as a first step in understanding the individual and collective importance of these species, while testing predictions on spatial patterns derived from previous studies in other regions. Surveys conducted at five beds across multiple time periods (April, June, August and October 2007) showed that San Francisco Bay eelgrass beds varied strongly in epifaunal community composition, total, and relative abundance, and that abundance differed markedly among time periods. In contrast to findings by others, morphologically complex flowering shoots frequently harbored greater numbers of epifauna (>2× and up to 10× more individuals) than vegetative shoots, but not different species assemblages. Similar to previous studies, several abiotic factors did not explain patterns in distribution and abundance among beds. The proportion of introduced species was very high (>90% of all individuals), a finding unique among seagrass epifaunal studies to date. Defining numerical patterns in epifaunal communities will inform related efforts to understand effects of epifaunal species and assemblages on eelgrass growth dynamics, seed production, and higher order trophic interactions over space and time.