北京地区植物源挥发性有机物(BVOCs)排放清单

利用现场连续监测的方法获取或采用专业气象部门资料以及林业资源二类清查数据的植被资料,运用Gl OBEIS模型,对北京地区2011年度植物源挥发性有机物(BVOCs)排放总量进行了估算,同时,也对所研究树种异戊二烯、单萜烯排放量进行了估算.结果表明,BVOCs的排放量分布情况与北京地区植被的分布情况有一定的相关性,并且VOCs的排放情况具有明显的季节依赖性.研究树种类型分为常绿乔木、落叶乔木、灌木、草本花卉,BVOCs排放量最大的依次为油松、苹果树、大叶黄杨和竹.其中,异戊二烯排放量最高为法桐,排放年通量可达313.92μg·(g·h)~(-1);单萜烯排放量最高为苹果树,排放年通量可达726.68μg·(g·h)~(-1).估算过程中的误差主要来自于植物标准排放因子的获取、叶生物量的计算,气象参数的变化也会给排放清单带来较大的不确定性.     

秋季羰基硫在植物与大气间的交换

利用静态箱法研究了秋季羰基硫(COS)在六种北京常见树种与大气间的交换．结果表明：法国梧桐、槐树、龙爪槐、玉兰、柳树对COS有吸收,油松没有吸收,树木与大气间COS的交换通量受树种、环境温度、光照、COS初始浓度等因素的影响．一般来说．温度高、光照强时,以上树种与大气间COS的交换强;空气中COS初始浓度高时,植物对COS的吸收通量高,植物对COS的吸收达到饱和较植物对CO2的吸收以及异戊二烯的排放持续时间长．     

杨树排放碳氢化合物的相关因素

采用封闭式气袋采样和气相色谱法，对杨树排放碳氢化合物（ＨＣｓ）的情况进行了调查，结果发现，与油松排放情况不同，杨树主要排放异戊二烯，约占其ＨＣｓ排放总量的９５％以上，且与温度，光强正相关，排放的日变化表明，杨树在正午有一排放高峰，夜间基本不排放，在春季和夏季日均气温分别为１９．２℃和２８．８℃，杨树的异戊二烯平均总排放速率分别为４．４和３９．８μｇ／ｇ．ｈ。     

亚热带竹林挥发性有机物排放的模拟

2012年7月至2013年1月,采用松弛涡度积累(Relaxed Eddy Accumulation)技术在我国浙江省亚热带竹林测量了挥发性有机物(BVOC)冠层尺度的排放通量,同步测量了气象参数、太阳辐射(总辐射、直接辐射、光合有效辐射PAR)。利用PAR能量平衡原理,建立了冠层尺度异戊二烯和单萜烯排放的经验模式,经验模式对于日变化、季节变化有较好的模拟。采用不同方法对经验模式进行检验,一般而言,BVOC的模拟值高于测量值。经验模式与MEGANv2.1全球生物排放模式对BVOC排放有比较一致的模拟结果,标准状况下(温度t=30℃、PAR=1 500μmol·m~(-2)·s~(-1)排放因子较接近(异戊二烯分别为4.00和3.60 mg·m~(-2)·h~(-1),单萜烯分别为0.12和0.16 mg·m~(-2)·h~(-1))。经验模式的计算结果表明:竹林BVOC排放主要集中于夏季(7-9月)且以异戊二烯为主(占BVOC排放的87.3%~95.8%)。利用经验模式计算了BVOC排放对各个因子(PAR、水汽、S/Q-散射因子,散射辐射/总辐射)变化的敏感性:当各个因子增加率大于40%时,异戊二烯对PAR的变化最敏感,其次是水汽因子,再次是S/Q;单萜烯对S/Q的变化最敏感,其次是水汽因子,再次是PAR;单萜烯比异戊二烯对S/Q的变化更敏感;异戊二烯和单萜烯对各因子变化的响应是非线性的。冠层尺度上BVOC的排放量与卫星测量的HCHO柱浓度(molec·cm~(-1))之间有良好的线性关系:异戊二烯排放量(mg·m~(-2)·h~(-1))=3.93×10~(-16)HCHO-2.81,单萜烯排放量(mg·m~(-2)·h~(-1))=1.24×10~(-17)HCHO-0.05。对比我国不同生态系统实测的排放通量、排放因子,异戊二烯排放以亚热带竹林最高,其次为温带森林,草地最低;单萜烯排放以温带森林最高,亚热带竹林次之,草地最低。     

基于动态模型的四川盆地植物挥发性有机物排放

本文在Guenther提出的经典天然源模型的基础上,结合WRF-CHEM简单天然源算法,针对气象变化和CMAQ模型数据格式特点,对BVOCs的算法进行了适当修正和改良,开发了可直接用于空气质量模型的BVOCs动态排放模型.研究结果表明,四川盆地2015年异戊二烯和单萜烯的年排放量分别为5.79×10~(-5)Tg C和3.05×10~(-5)Tg C,月排放具有显著差异;四川盆地植物异戊二烯、萜烯的排放量空间分布很好地反映了四川盆地的植被分布情况,异戊二烯、萜烯排放主要集中在盆地边缘的高山地区,两个物种的高浓度排放主要集中在气温较高、日照较强的夏季和初秋季节,且均在7月达到月均排放量的最大值.本研究建立的动态排放模型能够为空气质量模型提供一种快速衡算BVOCs排放的方法,具备一定的实用性.     

亚热带森林植物挥发性有机物(BVOCs)排放通量与大气甲醛之间的关系

陆地植物是大气中挥发性有机物的主要来源,准确获得中国典型生态系统,特别是亚热带森林植物挥发性有机物的排放通量,对碳循环、空气质量、大气化学和光化学等方面的研究都是一项具有重要意义的工作。2013年5月—2016年1月,采用松弛涡度积累(Relaxed Eddy Accumulation)和梯度技术在江西省亚热带人工林冠层上测量了植物挥发性有机物(BVOCs,包括异戊二烯和单萜烯)的排放通量,同步测量了气象参数、太阳辐射(总辐射、直接辐射、光合有效辐射PAR)等。基于冠层尺度BVOCs排放经验模式和测量数据,计算了2013年1月—2016年12月亚热带人工林BVOCs的排放通量。2013—2016年,通量塔100 km内异戊二烯的年排放量分别为1.2×10~5、2.4×10~5、2.1×10~5、1.6×10~5 kg,单萜烯的年排放量分别为2.1×10~5、2.1×10~5、1.9×10~5、2.0×10~5 kg。4年间,亚热带森林甲醛柱浓度表现出显著的季节变化,夏季高、冬季低,与BVOCs的排放特征基本一致。结合分析卫星测量的甲醛HCHO(molec·cm-2)柱浓度月平均数据,发现亚热带人工林BVOCs排放通量(mg·m~(-2)·h~(-1))与HCHO柱浓度(c_(HCHO))月均值之间存在良好的线性关系:异戊二烯排放通量F_1=1.29×10~(-16)c_(HCHO)-0.77、单萜烯排放通量F_2=1.02×10~(-16)c_(HCHO)-0.21、BVOCs排放通量F=2.31×10~(-16)c_(HCHO)-0.98。因此,基于卫星测量的HCHO数据,可以估算BVOCs排放通量,异戊二烯、单萜烯和BVOCs的计算偏差低于30%。该研究可为获取大范围BVOCs排放通量提供一种新方法,也为卫星数据的广泛应用提供了借鉴。     

我国几种典型树种非甲烷烃类的排放特征

采用封闭式采样法和带有预浓缩及程序升温装置的熔融毛细管柱气相色谱仪，对我国的松、柏、杨、槐等几种典型树种排放非甲烷烃类（ＮＭＨＣ）的组成和排放速率进行了定性和定量测定，初步确定了不同树种和的特征物种和排放规律，结果表明，针叶树种和阔叶树种排放的ＮＭＨＣ组成差别很大，各树种的排放规律除了与自身的结构和生理活动等在内在因素有关外，还在不同程度上受到外界因素（主要是温度和光强）的影响，一般温度越高，光强     

亚热带森林BVOCs排放和其影响因子之间的相互关系

利用植物挥发性有机物(BVOCs)排放经验模式以及太阳辐射、气象参数测量数据,计算了2013年5月—2016年12月年江西省亚热带人工林BVOCs的排放通量。为了深入研究BVOCs排放与其控制因子之间的相互作用,将大气中物质含量(以S/Q表示,S、Q分别为水平面散射辐射和总辐射)在0.0—1.0区间以0.05间隔分区,同时将BVOCs排放通量、其他参数一同分区,计算了所有参数在每个分区的平均值。进一步研究了对应于所有S/Q分区的BVOCs排放通量与其影响因子(PAR、气温、水汽含量、S/Q)之间的相互关系。研究发现,异戊二烯、单萜烯、BVOCs排放通量,(1)在PAR1 180μmol·m-2·s-1的条件下,均随PAR增加线性增加,单萜烯排放比异戊二烯排放对于PAR的响应更加敏感。(2)随气温的升高而增加,当气温达到26℃时达到峰值;然后随气温的升高而下降。(3)随水汽含量的增加而增加,当水汽含量为24 hPa时达到峰值,之后随水汽含量的增加而下降。(4)当S/Q≤0.55之时,随S/Q的增加而增加;当S/Q≥0.55后,随S/Q的增加而下降。PAR、气温、水汽含量、S/Q共同影响着BVOCs的排放,其中大气中的物质含量S/Q是一个关键参数,它控制着BVOCs随其主要影响因子(PAR、气温、水汽含量、S/Q)变化的正负作用及其转折点。将大气中物质含量分区,研究各个分区内BVOCs排放通量和其他各个参数之间的相互关系,有助于深入了解与BVOCs排放有关的物理化学生物过程及其相互作用、化学和光化学机制。建议将这一方法用于未来研究。BVOCs排放模型揭示出异戊二烯和单萜烯在生成二次有机气溶胶方面存在竞争或相互抑制的机制。     

北京城区夏冬两季VOCs时间变化和光化学特征的质子转移反应飞行时间质谱(PTR-TOF-MS)观测

为增进对北京地区不同季节大气挥发性有机物(VOCs)变化特征的认识,利用高时间分辨率质子迁移反应-飞行时间质谱(PTR-TOF-MS)于2016年在北京城区开展了VOCs(甲醛、乙醛、丙酮、异戊二烯、苯、甲苯和8碳芳香烃)夏季(6月8日—20日)和冬季(11月22日—12月10日)的连续观测.VOCs体积分数(浓度)的均值为(夏季/冬季,×10~(-9)):甲醛(8.56/24.58)、乙醛(3.95/7.57)、丙酮(5.06/3.50)、异戊二烯(0.66/0.52)、苯(0.53/1.78)、甲苯(1.03/2.54)、8碳芳香烃(1.34/3.42).受大气扩散条件的影响,夏冬两季大部分VOCs浓度波动趋势相近,仅异戊二烯在夏季拥有明显的白天浓度高于夜间的时间序列,其白天的高浓度与植被排放较强有关.由日变化可见:冬季,所有VOCs在中午浓度处于全天较低水平,在早高峰期间VOCs浓度上升明显;夏季,甲醛、乙醛和丙酮等3种含氧VOCs(OVOCs)在中午有短暂的浓度峰值,这与它们光化学二次生成加快有关.由VOC与苯浓度比值的日变化可知:冬季与夏季类似,中午前后3种OVOCs(甲醛、乙醛和丙酮)的光化学生成以及甲苯和8碳芳香烃的光化学消耗都会增强,只是冬季增强的程度明显弱于夏季;在夏冬两季,甲醛中午的光化学生成速率均强于乙醛和丙酮.8碳芳香烃光化学消耗速率大于甲苯的速率仅出现在夏季;异戊二烯在冬季白天不存在植被排放增强的现象,但有光化学消耗加快的特征;夏季北京城区VOCs以机动车排放影响为主,而冬季VOCs还可能来自于燃煤排放.     

盐胁迫对欧美杂交杨异戊二烯释放和光合参数的影响

为揭示2种欧美杨(Populus deltoides×Populus nigra)光合速率、异戊二烯释放速率、生长形态对盐胁迫的响应,以欧美杨895、欧美杨1388为试验材料,用浓度为0、0.18 mol/L的NaCl溶液对其进行处理,测定不同处理下2种欧美杨气体交换指标、异戊二烯释放的相关参数以及生物量相关的生长指标.结果显示:盐胁迫显著降低了2种欧美杨的净光合速率(P_n)、气孔导度(g_s)及蒸腾速率(T_r),但其胞间CO_2浓度(C_i)并未受到影响;盐胁迫下,2种欧美杨的异戊二烯释放速率和异戊二烯合酶反应系数明显降低,但异戊二烯的直接前体物二甲基烯丙基二磷酸酯(DMADP)库容在统计学上并没受到显著的影响,这说明盐胁迫下异戊二烯释放速率的降低主要是由异戊二烯合成酶活性的降低所导致;2种欧美杨的相对生长速率和总干物质量在盐胁迫下均显著下降,其中1388品种的根和茎干重占总干物质量的比例显著高于895品种,而其叶干重刚好相反,说明2个品种不同器官的生物量分配在盐胁迫下存在差异.综上所述,2种欧美杨对盐胁迫的响应相似,抗逆性也没有表现出显著差异,但其异戊二烯释放速率以及光合速率下降的调控机制有所差异,这很可能是2个品种不同器官的生物量分配产生差异的原因.     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.     

Effects of Coffee Management on Deforestation Rates and Forest Integrity

Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest‐agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973–2010) across elevations in 2 forest‐agriculture mosaic landscapes (1100 km² around Bonga and 3000 km² in Goma‐Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee‐growing elevations compared with at higher elevations (?10/20% vs. ?40/50% comparing relative rates at 1800 m asl and 2300–2500 m asl, respectively). Within the coffee‐growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest‐specialist species. Even if the presence of coffee slows down the conversion of forest to annual‐crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administración Cafetalera sobre las Tasas de Deforestación y la Integridad de los Bosques     

Globalization of the Cashmere Market and the Decline of Large Mammals in Central Asia

As drivers of terrestrial ecosystems, humans have replaced large carnivores in most areas, and human influence not only exerts striking ecological pressures on biodiversity at local scales but also has indirect effects in distant corners of the world. We suggest that the multibillion dollar cashmere industry creates economic motivations that link western fashion preferences for cashmere to land use in Central Asia. This penchant for stylish clothing, in turn, encourages herders to increase livestock production which affects persistence of over 6 endangered large mammals in these remote, arid ecosystems. We hypothesized that global trade in cashmere has strong negative effects on native large mammals of deserts and grassland where cashmere‐producing goats are raised. We used time series data, ecological snapshots of the biomass of native and domestic ungulates, and ecologically and behaviorally based fieldwork to test our hypothesis. In Mongolia increases in domestic goat production were associated with a 3‐fold increase in local profits for herders coexisting with endangered saiga (Saiga tatarica).That increasing domestic grazing pressure carries fitness consequences was inferred on the basis of an approximately 4‐fold difference in juvenile recruitment among blue sheep (Pseudois nayaur)in trans‐Himalayan India. Across 7 study areas in Mongolia, India, and China's Tibetan Plateau, native ungulate biomass is now <5% that of domestic species. Such trends suggest ecosystem degradation and decreased capacity for the persistence of native species, including at least 8 Asian endemic species: saiga, chiru (Pantholops hodgsoni), Bactrian camel (Camelus bactrianus), snow leopard(Panthera uncia), khulan(Equus hemionus), kiang (E. kiang), takhi (E. przewalski), and wild yak (Bos mutus). Our results suggest striking yet indirect and unintended actions that link trophic‐level effects to markets induced by the trade for cashmere. Globalización del Mercado de Cachemira y la Declinación de Mamíferos Mayores en Asia Central