Quantifying forest fragmentation spatial process in the developing State of Selangor,peninsular Malaysia

Forest fragmentation has several phases; thus, the ecological significance of each phase during a particular period of time must be interpreted. To interpret, this study quantifies the magnitude of forest loss and the changes in the temporal pattern of fragmentation in the State of Selangor, peninsular Malaysia. Using the decision tree model of land transformation, five phases of forest fragmentation were identified: perforation, dissection, dissipation, shrinkage and attrition. This analysis showed that the magnitude of forest loss was the highest during the dissipation phase. The patchiness analysis showed that dissipation contributes to the highest environmental uncertainty found for the forest patches. This study can be considered a first step in the exploration of the properties and the behavioural pattern shown by the spatial process of forest fragmentation.     

Systematic Temporal Patterns in the Relationship Between Housing Development and Forest Bird Biodiversity

As people encroach increasingly on natural areas, one question is how this affects avian biodiversity. The answer to this is partly scale‐dependent. At broad scales, human populations and biodiversity concentrate in the same areas and are positively associated, but at local scales people and biodiversity are negatively associated with biodiversity. We investigated whether there is also a systematic temporal trend in the relationship between bird biodiversity and housing development. We used linear regression to examine associations between forest bird species richness and housing growth in the conterminous United States over 30 years. Our data sources were the North American Breeding Bird Survey and the 2000 decennial U.S. Census. In the 9 largest forested ecoregions, housing density increased continually over time. Across the conterminous United States, the association between bird species richness and housing density was positive for virtually all guilds except ground nesting birds. We found a systematic trajectory of declining bird species richness as housing increased through time. In more recently developed ecoregions, where housing density was still low, the association with bird species richness was neutral or positive. In ecoregions that were developed earlier and where housing density was highest, the association of housing density with bird species richness for most guilds was negative and grew stronger with advancing decades. We propose that in general the relationship between human settlement and biodiversity over time unfolds as a 2‐phase process. The first phase is apparently innocuous; associations are positive due to coincidence of low‐density housing with high biodiversity. The second phase is highly detrimental to biodiversity, and increases in housing density are associated with biodiversity losses. The long‐term effect on biodiversity depends on the final housing density. This general pattern can help unify our understanding of the relationship of human encroachment and biodiversity response. Patrones Sistemáticos Temporales en la Relación entre Desarrollos Urbanos y la Biodiversidad de Aves de Bosque     

Effects of payments for ecosystem services on wildlife habitat recovery

Conflicts between local people's livelihoods and conservation have led to many unsuccessful conservation efforts and have stimulated debates on policies that might simultaneously promote sustainable management of protected areas and improve the living conditions of local people. Many government‐sponsored payments‐for‐ecosystem‐services (PES) schemes have been implemented around the world. However, few empirical assessments of their effectiveness have been conducted, and even fewer assessments have directly measured their effects on ecosystem services. We conducted an empirical and spatially explicit assessment of the conservation effectiveness of one of the world's largest PES programs through the use of a long‐term empirical data set, a satellite‐based habitat model, and spatial autoregressive analyses on direct measures of change in an ecosystem service (i.e., the provision of wildlife species habitat). Giant panda (Ailuropoda melanoleuca) habitat improved in Wolong Nature Reserve of China after the implementation of the Natural Forest Conservation Program. The improvement was more pronounced in areas monitored by local residents than those monitored by the local government, but only when a higher payment was provided. Our results suggest that the effectiveness of a PES program depends on who receives the payment and on whether the payment provides sufficient incentives. As engagement of local residents has not been incorporated in many conservation strategies elsewhere in China or around the world, our results also suggest that using an incentive‐based strategy as a complement to command‐and‐control, community‐ and norm‐based strategies may help achieve greater conservation effectiveness and provide a potential solution for the park versus people conflict.     

Inorganic elemental concentrations in birch bolete mushroom (Leccinum scabrum) and top soil: contamination profiles,bioconcentation and annual variations

Abstract

Analysis of inorganic and organic contaminants in foodstuffs aids in understanding the human exposure to these compounds via consumption. In this study, an edible mushroom species (Leccinum scabrum) and top soil samples were analysed for essential and toxic substances including phosphorus and inorganic elements over a period of three fruiting seasons. Analysis of silver (Ag), aluminium (Al), barium (Ba), calcium (Ca), cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), phosphorus (P), lead (Pb), rubidium (Rb), strontium (Sr) and zinc (Zn) in mushrooms and topsoil were performed using inductively coupled plasma optical emission spectroscopy (ICP-OES) with ultrasonic cross flow nebulizer. Total mercury was determined by cold-vapour atomic absorption spectroscopy (CV-AAS). The results exhibited wide variation in concentrations of metals between soil and mushroom (cap and stipes) during three fruiting seasons. Positive bioconcentration factors (BFCs) indicate on bioaccumulation of several metals including, Cd, Cu, Hg, K, Mg, Na, P, Rb and Zn in caps and stipes of fruitbodies of this mushroom, while other metals such as Al, Ba, Ca, Co, Fe, Mn, Ni, Pb and Sr were not exhibiting significant positive BFCs. Over a period studied, the caps were characterised by different (p?<?0.05) concentrations of Al, Co, Cu, Hg, Mn, Ni, P, Pb and Sr. Contamination profiles, temporal fluctuations, BCFs should be taken into consideration when assessing the nutritional value of this mushroom.     

Ambio’s legacy on monitoring,impact, and management of acid rain: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Acidification

Early studies published in Ambio showed large-scale acidification of lakes in southern Sweden and Norway from acid rain. These studies were important for delimiting various scientific issues and thus for eventually contributing to legislation, which reduced emissions of sulfur dioxide and nitrogen oxides and helped to mitigate this major environmental problem. Long-term studies and monitoring in Sweden and Norway and at Hubbard Brook Experimental Forest in New Hampshire helped guide this legislation in Europe and in the USA.     

重庆缙云山4种典型植被覆盖下汞的释放通量及影响因素

为了揭示不同植被覆盖下土壤/大气界面释汞通量及其交换特征,在缙云山国家级自然保护区内选择4种典型植被覆盖类型(常绿阔叶林、楠竹林、灌木林以及草地)为研究对象,连续同步监测不同植被覆盖下土/气界面汞释放通量,同时考察各环境因子对土壤释汞的影响.结果表明,缙云山在4种不同植被覆盖下土壤汞释放通量具有明显的差异,总体表现为楠竹林[17.77 ng·(m~2·h)~(-1)]草地[17.58 ng·(m~2·h)~(-1)]灌木林[16.87 ng·(m~2·h)~(-1)]常绿阔叶林[14.32 ng·(m~2·h)~(-1)];不同植被覆盖下土壤释汞通量在季节变化上呈现相似的规律性,但不同植被覆盖类型之间也存在明显差异,主要体现在暖季汞释放通量高于冷季;缙云山地区不同林植被覆盖下土壤释汞通量存在明显的日变化;气象因素光照强度、气温、土温和相对湿度,对土/气界面汞释放通量影响也不相同,气温为常绿阔叶林,灌木林与楠竹林的主要影响因子,光照强度为草地的主要影响因子.     

人为干扰对小兴安岭森林湿地土壤碳组分和酶活性的影响

以小兴安岭落叶林沼泽湿地为研究对象,对比研究皆伐地、火烧地和落叶松湿地土壤碳组分和酶活性.结果表明:(1)3种湿地类型土壤SOC含量表现为对照地显著高于皆伐地和火烧地(p0.05),在0~10 cm土层中皆伐地与对照地相比降低了58.38%,火烧地与对照地相比降低了61.96%.皆伐地与火烧地在不同土层的土壤中SOC含量差异不显著(p0.05);DOC含量对照地显著高于皆伐地和火烧地(p0.05).在0~10cm土层中火烧地DOC含量是皆伐地的1.99倍,两者差异不显著(p0.05);不同干扰方式对土壤MBC含量影响的差异主要表现在0~10 cm的土层土壤,对照地分别比皆伐地和火烧地高23.13%和95.79%(p0.05).在不同的土层中皆伐地MBC含量均大于火烧地,与SOC含量的变化趋势一致.(2)与对照地相比,皆伐地与火烧地0~10 cm土层的土壤蔗糖酶活性分别降低了45.59%和36.76%,脲酶活性显著降低了18.22%和55.69%(p0.05),蛋白酶活性降低了19.65%和17.34%,淀粉酶活性降低了6.29%和10.69%.土壤碳组分和酶活性在垂直方向上均表现为随着土层深度增加而减小.皆伐和火烧造成森林湿地土壤碳组分和酶活性降低.     

双台子河口湿地植被修复生境健康评价方法研究

以2014—2015年双台子河口滨海湿地植被修复20个站位调查资料为基础,对湿地修复结构指标、功能指标和环境指标进行研究,结合湿地生态系统健康理论,构建湿地生态环境健康评价指标体系。运用层次分析法(AHP)确定权重,对各个指标赋予权重,将健康评价分为3个等级,确立了生态健康评价方法,对近岸破损湿地翅碱蓬修复生境进行评价。进一步引用评价净影响值(EI)方法判断生境修复前、后的健康对比状态,从而确定翅碱蓬对该破损湿地的修复效果显著。从景观生态学和健康评价角度分析来看,建立此评价方法是可行的,可为今后湿地的管理与保护提供科学依据。     

喀斯特常绿与落叶阔叶混交林过去50年来的碳循环模拟

通过对Forest-DNDC模型的植被和土壤参数本地化校准,以气象插值数据为输入,模拟了贵州省普定县高原型喀斯特次生常绿与落叶阔叶混交林1965~2014年的土壤、植被和生态系统碳循环特征。结果表明,与冷模拟和实测值相比,参数本地化校准后的模型能更准确地模拟春、秋、冬3个季节的土壤呼吸动态,而模拟的夏季土壤呼吸偏小;但统计检验指出,参数修订后的Forest-DNDC模型能够较好地模拟喀斯特森林土壤呼吸,降低了模拟误差,可用于喀斯特常绿与落叶阔叶混交林碳动态的模拟。进一步分析发现,1965~2014年喀斯特森林的碳通量除模拟早期的前3~4年急剧增加之外,随后总初级生产力(GPP)保持相对稳定,植物呼吸(Rplant)和生态系统呼吸(R_(ecosystem))随着森林发育而增加,土壤呼吸(R_(soil))减少,植被净初级生产力(NPP)呈迅速减小趋势;净生态系统碳交换量(NEE)亦较迅速下降,在2013年达到最低值-0.17 t C/ha,喀斯特森林由碳汇变为弱碳源。相关分析表明,年均温度和年降水对喀斯特常绿与落叶阔叶混交林的GPP和R_(soil)没有显著影响,但却显著影响NPP、R_(plant)、R_(ecosystem)和NEE。     

西北干旱区煤炭基地生态蓄水模式研究

西北干旱区煤炭开采产生的矿井水大多就近排放,利用率低.同时,该地区水资源严重缺乏,尤其是生态用水紧缺,煤炭开采造成地下水资源浪费和生态用水紧缺的矛盾局面.为缓解这一矛盾,提出地面人工湿地及生态储水的设想,构建两种基于生态用水的地面处理储存矿井水的模式,该模式下矿井水通过下渗补给潜水含水层,进而供给地表植被;另一方面,利用干旱区蒸发量大的特点借助低空大气环流输送水份,增加局部降水量,从而实现改善生态环境的目的.