一株中度嗜盐菌Halomonas sp.NY-011的耐盐特性及机理

对本实验室分离到的一株中度嗜盐菌Halomonas sp.NY-011的耐盐特性和耐盐机理进行了初步研究.NY-011在LB培养基中最大能耐受260g/LNaCl浓度,在M63培养基中能耐受大于150g/LNaCl浓度.Cl-的缺少对NY-011的耐盐生长有明显抑制,K+较Li+和Mg2+更适合于为NY-011提供内部渗透压力.NY-011通过在胞内积累K+、游离氨基酸及其他相容性溶质对抗胞外渗透压力.NY-011胞内相容性溶质组成随培养基NaCl浓度变化而变化,四氢嘧啶是最主要的组成成分,含量随培养基NaCl浓度增加而增加,120g/LNaCl时浓度可达到71.5mg/g干重.NY-011还可吸收胞外的四氢嘧啶和甜菜碱以平衡外界高渗透压.随着培养基中NaCl浓度的提高,NY-011菌体蛋白的合成受到明显抑制.图5表2参24     

一株产脂肪酶嗜盐菌的鉴定及耐盐机理

从采自内蒙古锡林浩特地区盐湖的样品中筛选到产脂肪酶嗜盐菌JNPH-3,该菌株可在含有1.5～5mol/L NaCl的培养基上生长,最适生长温度45℃,最适pH7～9.5.经形态学分析、生理生化实验及16SrDNA鉴定,JNPH-3菌株为Halorubrum aidingense,属于极端嗜盐菌.JNPH-3菌株在生长过程中专一性依赖Na+,对Cl-依赖性较小,K+浓度变化对菌体生长无明显影响.高效液相色谱分析表明,JNPH-3菌株在液体复合培养基中能够产生四氢嘧啶,且与环境中盐浓度呈负相关,说明JNPH-3体内除存在产生四氢嘧啶的机制来维持渗透平衡,还有其它机制来维持细胞正常生长.     

一株积聚四氢嘧啶的青海湖盐单胞菌的分离及特性

从青海湖采集20份水样,利用RM高盐培养基分离获得35株嗜盐菌.选取其中一株优势中度嗜盐菌QHL25进行形态学和生理生化特征分析,结果表明:QHL25菌落圆形或椭圆形,乳白色,不透明,中心突出,边缘透明,生长盐度为0~2.9 mol/L,最适生长盐度为1.45 mol/L.显微形态呈短杆状,革兰氏染色呈阴性,单个或成串排列.最适生长pH为8.5,最适生长温度为37℃.16S rDNA序列分析表明:该菌株与盐单胞菌属(Halomonas sp.)相似性为98%;结合形态特征和生理生化特征分析,初步认定该菌株隶属于γ变形杆菌纲(Gammaproteobacteria)海洋螺菌目(Oceanospirillales)盐单胞菌科(Holomonadaceae)盐单胞菌属(Holomonas).薄层层析(TLC)定性分析可知QHL25胞内含有相容溶质四氢嘧啶;高效液相色谱(HPLC)定量分析表明,在1.7 mol/L的NaCl浓度下,四氢嘧啶含量约为36.70 mg/g(细胞干重).     

水中主要阳离子对铜绿微囊藻生长及多糖的影响

通过室内培养试验,在65μmol·m-2·s-1光照度和12 h∶12 h光暗比下,模拟野外水体中铜绿微囊藻（Microcystis aeruginosa）的生长,研究了水中主要阳离子Ca、Mg、K、Na质量浓度的变化对铜绿微囊藻生长以及多糖的影响。依据自然水体中Ca、Mg、K、Na的实际浓度水平结合已有研究得到的抑制浓度,试验分别设定了5个质量浓度梯度的培养基,其中Ca质量浓度梯度为0、10、20、50、100 mg·L-1,Mg质量浓度梯度为0、2、5、10、20 mg·L-1,K质量浓度梯度为5、10、20、50、100 mg·L-1,Na质量浓度梯度为18、30、50、100、200 mg·L-1。试验测定的生理生化指标包括培养周期内每天铜绿微囊藻的藻细胞密度和对数生长期内铜绿微囊藻溶解性胞外多糖（sEPS）、固着性胞外多糖（bEPS）和胞内多糖（IPS）的含量。试验结果表明：低质量浓度的Ca对微囊藻的生长没有明显影响,高质量浓度的Ca（〉50 mg·L-1）会抑制铜绿微囊藻的生长但同时铜绿微囊藻合成多糖总量（TPS）会增加,Ca质量浓度的增大对铜绿微囊藻胞外多糖的分泌呈现先促进后抑制的趋势,并在刺激铜绿微囊藻细胞分泌多糖的同时会促进其溶解。Mg缺失时,铜绿微囊藻的生长会受到显著的抑制,较高质量浓度的Mg（〉5 mg·L-1）也会抑制铜绿微囊藻的生长但同时铜绿微囊藻合成多糖总量（TPS）会增加,Mg在适宜质量浓度（5 mg·L-1）会抑制多糖分泌、防止多糖溶解。K离子质量浓度的变化对微囊藻的生长无明显影响但铜绿微囊藻TPS的量呈现先增加后减少的趋势,K对多糖的分泌并没有显著影响,但对多糖的溶解呈现先促进后抑制的作用。Na离子质量浓度的变化对铜绿微囊藻的生长以及合成TPS的量均无明显影响,Na质量浓度增大对多糖的分泌的影响与Ca的一致,但影响的程度明显小于Ca的影响,其质量浓度的增加对多糖的溶解过程有轻微的促进作用。     

Halomonas socia NY-011~T中四氢嘧啶合成基因簇ectABC和ectD的克隆及其功能鉴定

由ectA、ectB、ectC和ectD编码的酶可以催化对细胞起保护作用的四氢嘧啶类物质的生物合成,嗜盐菌新种Halomonas socia NY-011~T ectABC和ectD为四氢嘧啶和羟基四氢嘧啶的生产提供新的基因来源.通过SEFA-PCR步移方法从Halomonas socia NY-011~T中克隆ectA、ectB、ectC和ectD基因,并分别构建ectABC和ectD的原核表达质粒,在E.coli BL21(DE3)中异源表达,利用SDS-PAGE对重组蛋白进行鉴定,通过ACQUITY UPLC MS/MS检测四氢嘧啶和羟基四氢嘧啶的生成.结果显示:H.socia NY-011~T的四氢嘧啶合成基因ectA、ectB、ectC形成基因簇ectABC(KP717055-57),大小为2 506 bp,四氢嘧啶羟化酶基因ectD大小为942 bp(KP717058),与近源种H.elongata DSM258同源性分别为81%和78%;SDS-PAGE检测到4种融合蛋白,大小(M_r)分别为21.6×10~3、46.4×10~3、14.4×10~3、55.3×10~3,与预期相符;利用ACQUITY UPLC MS/MS发现仅表达ectABC的重组菌株[E.coli BL21(DE3)/pltac-ABC]中只存在四氢嘧啶,而在表达ectABC和ectD的重组菌株[E.coli BL21(DE3)/pltac-ABC/pETect D]中检测到四氢嘧啶和羟基四氢嘧啶.本研究从H.socia NY-011~T中分离得到的四氢嘧啶类物质的合成基因,能够在E.coli BL21(DE3)中异源表达并行使功能,为四氢嘧啶类物质异源生产提供了新的基因来源.     

高效液相色谱检测青海湖嗜盐菌胞内积聚的相溶物质四氢嘧啶

从20份青海湖水样中,分离获得了35株中度嗜盐菌株.耐盐梯度实验表明:水体中以中度嗜盐菌为主,约占65.7%;弱嗜盐菌次之,约占25.7%;非嗜盐菌与耐盐菌相对较少,约占8.5%.采用80%乙醇法抽提中度嗜盐菌胞内的Ectoine,利用TLC和HPLC分析,结果表明:青海湖中度嗜盐菌中,大多数胞内积聚相溶物质Ectoine;在最适生长盐度下,中度嗜盐菌QHL1、QHL5、QHL10、QHL26和QHL28的胞内Ectoine含量分别为258.6μg·mL-1、325.47μg·mL-1、208.8μg·mL-1、292.31μg·mL-1和295.13μg·mL-1,以此初步获得5株具有Ectoine高产潜力的野生菌株.     

α-MnO2/水界面磺胺嘧啶的氧化降解动力学

通过反歧化法合成α-MnO2,并以α-MnO2为氧化剂,研究了不同锰氧化物剂量、不同磺胺嘧啶初始浓度和不同pH值下α-MnO2/水界面磺胺嘧啶的氧化降解动力学,并讨论了不同的反应条件对反应动力学的影响.结果表明,α-MnO2可以有效的氧化降解甚至矿化磺胺嘧啶,反应符合准一级反应动力学方程,在25 ℃,pH 4.6的反应条件下,反应120 min后,11.5 mmol·L-1的α-MnO2对0.02 mmol·L-1磺胺嘧啶去除率达到99.98%.α-MnO2剂量和磺胺嘧啶的初始浓度均与磺胺嘧啶氧化降解的动力学常数呈显著正相关关系,相关因子分别为0.67和0.18,相关系数R分别达到0.9961和0.9979;而磺胺嘧啶的降解动力学常数与体系的pH则呈显著负相关关系,相关因子为-0.25,相关系数R达到0.9975.初步探讨了锰氧化物氧化降解磺胺嘧啶机理.研究表明,土壤及沉积物中的锰氧化物可以有效促进其中残留抗生素类药物磺胺嘧啶的降解消除过程.     

青海湖嗜盐菌的分离与优势菌株QHL5的特性

采用高盐选择性培养基从20份青海湖水样中筛选分离获得35株青海湖嗜盐微生物.耐盐梯度实验分析表明:水体中以中度嗜盐菌为主,约占65.7%;弱嗜盐菌次之,约占25.7%;非嗜盐菌与耐盐菌相对较少,约占8.5%.其中优势菌QHL5的生长盐度耐受范围为0.04～3.0 mol/L,最适生长范围为0.3～0.9 mol/L,隶属于中度嗜盐菌.菌体形态和生长特性分析表明:QHL5菌落大小为4～6 mm,圆形或椭圆形,边缘整齐厚实,乳白色,中间微隆起,不透明,革兰氏染色阴性.显微形态呈杆状,最适生长pH为8.5～9.5,最适生长温度为35℃.生理生化、16S rRNA的全序列Blast和系统发育分析表明:QHL5菌株分类定位于γ变形菌纲海洋螺菌目盐单胞菌属樊氏盐单胞菌(Halomonas ventosae).通过80%乙醇法抽提胞内相溶物质,采用TLC法检测出该菌积聚四氢嘧啶.     

西藏日喀则地区夏、冬季大气颗粒物水溶性离子粒径分布特征

为研究日喀则不同粒径大气颗粒物中水溶性无机离子的组成特征,利用Andersen分级撞击式采样器在夏、冬季进行大气颗粒物分级采样,采用离子色谱测定NH+4、Ca2+、K+、Mg2+、Na+、SO2-4、NO-3和Cl-等8种离子浓度.结果表明,夏、冬季总离子浓度分别为9648±3030、4925±1138 ng·m-3.夏季离子浓度高低顺序为Cl-﹥Ca2+﹥NH+4﹥Na+﹥SO2-4﹥NO-3﹥K+﹥Mg2+,Cl-、Ca2+、NH+4和Na+占总离子浓度的比重为74.9%;冬季水溶性无机离子浓度高低顺序为Cl-﹥SO2-4﹥NH+4﹥NO-3﹥Ca2+﹥Na+﹥K+﹥Mg2+,Cl-、SO2-4、NH+4和NO-3占总离子浓度的比重为88.0%.夏、冬季大气颗粒物中所有水溶性无机离子的粒径分布均成双峰型.夏季,大气颗粒物中SO2-4与Mg2+(r=0.951)、Ca2+(r=0.947),NO-3与Mg2+(r=0.904)、Ca2+(r=0.843),在0.01水平(双侧)上均显著相关;冬季,细粒子中K+与Cl-(r=0.740)、SO2-4(r=0.929)及NO-3(r=0.920),在0.01水平(双侧)上显著相关.     

水体中微污染磺胺嘧啶药物的氧化降解

环境中残留的微量抗生素药物对生态环境的危害和修复越来越受到人们的重视.对广泛使用的广谱抗菌素磺胺嘧啶(SD)微污染水体的Fenton氧化降解进行了研究,探讨了SD、H2O2、Fe2+质量浓度、pH和反应时间对SD降解率的影响.研究结果表明,当SD初始质量浓度为2.0 mg·L-1,水体中添加H2O2、Fe2+至质量浓度分别为30 mg·L-1和1.25 mg·L-1,反应时间为60 min时,降解率可以达到99.8%,说明Fenton法是一种有效的处理微量磺胺嘧啶带来的水体污染的修复方法.     

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.     

Importance of greater interdisciplinarity and geographic scope when tackling the driving forces behind biological invasions

Invasive non-native species are important drivers of ecosystem change, yet the driving forces of biological invasions themselves are poorly understood. Such information is essential to ensure policies focus on the most relevant drivers, and that future scenarios capture the full range of potential outcomes for invasive non-native species. I carried out a bibliometric analysis of articles published from 2000 to 2020 that address either invasive non-native species or biodiversity and ecosystem services and that also mention 1 or more drivers of ecosystem change. I examined 5 indirect drivers (demographic, economic, governance, sociocultural, and technological) and 6 direct drivers (climate change, invasive non-native species, land-use or sea-use change, natural hazards, pollution, and resource extraction). Using the Web of Science core collection of citation indexes, I undertook searches of article titles and keywords and retrieved 27,462 articles addressing invasive non-native species and 110,087 articles dealing with biodiversity or ecosystem services. Most research to date on biological invasions as well as on biodiversity and ecosystem services has focused on anthropogenic direct drivers of ecosystem change rather than indirect drivers. Yet currently, less than 18% of articles addressing biological invasions examined drivers of ecosystem change, a similar level to that found over 20 years ago for biodiversity or ecosystem services. Knowledge of the drivers of biological invasions is limited, emphasizes tractable drivers over those that require an interdisciplinary approach, and is biased toward developed economies. Drivers generally deemed important for biological invasions, such as governance and resource extraction, accounted for less than 2% of research effort. The absence of a systematic understanding of the forces that drive invasive non-native species and how they interact means that attempts to mitigate or forecast biological invasions are likely to fail. To address biological invasions requires a much better orientation of national and international research on drivers in relation to both their actual importance as well as their policy relevance.     

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.     

Mitigating the effects of climate change on the nests of sea turtles with artificial irrigation

For sea turtles, like many oviparous species, increasing temperatures during development threaten to increase embryonic mortality, alter offspring quality, and potentially create suboptimal primary sex ratios. Various methods are being implemented to mitigate the effects of climate change on reproductive success, but these methods, such as breeding programs, translocations, and shading, are often invasive and expensive. Irrigation is an alternative strategy for cooling nests that, depending on location, can be implemented relatively quickly and cheaply. However, multiple factors, including ambient conditions, nest substrate, and species characteristics, can influence irrigation success. Additionally, irrigation can vary in duration, frequency, and the volume of water applied to nests, which influences the cooling achieved and embryonic survival. Thus, it is critical to understand how to maximize cooling and manage risks before implementing irrigation as a nest-cooling strategy. We reviewed the literature on nest irrigation to examine whether artificial irrigation is feasible as a population management tool. Key factors that affected cooling were the volume of water applied and the frequency of applications. Embryonic responses varied with species, ambient conditions, and the timing of irrigation during development. Nest inundation was the key risk to a successful irrigation regime. Future irrigation regimes must identify clear targets, either primary or adult sex ratios, that maximize population viability. Monitoring population responses and adjusting the irrigation regime in response to population characteristics will be critical. Most studies reported on the manipulation of only one or two variables, further research is required to understand how altering multiple factors in an irrigation regime influences the cooling achieved and embryonic responses.     

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.     

Positive and Negative Effects of a Threatened Parrotfish on Reef Ecosystems

Species that are strong interactors play disproportionately important roles in the dynamics of natural ecosystems. It has been proposed that their presence is necessary for positively shaping the structure and functioning of ecosystems. We evaluated this hypothesis using the case of the world's largest parrotfish (Bolbometopon muricatum), a globally imperiled species. We used direct observation, animal tracking, and computer simulations to examine the diverse routes through which B. muricatum affects the diversity, dispersal, relative abundance, and survival of the corals that comprise the foundation of reef ecosystems. Our results suggest that this species can influence reef building corals in both positive and negative ways. Field observation and simulation outputs indicated that B. muricatum reduced the abundance of macroalgae that can outcompete corals, but they also feed directly on corals, decreasing coral abundance, diversity, and colony size. B. muricatum appeared to facilitate coral advancement by mechanically dispersing coral fragments and opening up bare space for coral settlement, but they also damaged adult corals and remobilized a large volume of potentially stressful carbonate sediment. The impacts this species has on reefs appears to be regulated in part by its abundance—the effects of B. muricatum were more intense in simulation scenarios populated with high densities of these fish. Observations conducted in regions with high and low predator (e.g., sharks) abundance generated results that are consistent with the hypothesis that these predators of B. muricatum may play a role in governing their abundance; thus, predation may modulate the intensity of the effects they have on reef dynamics. Overall our results illustrate that functionally unique and threatened species may not have universally positive impacts on ecosystems and that it may be necessary for environmental managers to consider the diverse effects of such species and the forces that mediate the strength of their influence. Efectos Positivos y Negativos de un Pez Loro Amenazado Sobre Ecosistemas Arrecifales     

Form-specific fragances fromOphrys insectifera L. (Orchidaceae) attract species of different pollinator genera. Evidence of sympatric speciation?

Two closely related forms ofOphrys insectifera were observed in the field to attract different pollinator species selectively.O. i. ssp.insectifera attracted males of two species ofArgogorytes (Sphecidae, Hymenoptera Aculeata) andO. i. ssp.aymoninii attractedAndrena combinata males (Andrenidae, Apoidea, Hymenoptera Aculeata). A third form,O. aff.i. ssp.insectifera, attracted none of these three species. Volatile compounds from flowers and inflorescences of the three forms (originating from Öland, Sweden, and Aveyron, France) were collected, using entrainment, enfleurage, and solvent extraction techniques, and identified by gas chromatography — mass spectrometry. Scent differences between the three forms were confirmed in the amounts of aliphatic hydrocarbons (C₁₁–C₁₉), methyl esters (C₁₄–C₁₈), short chain aliphatic 1-alcohols (C₆–C₁₂), and monoterpene alcohols (C₁₀).     

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     

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.