Using Remote Sensing to Evaluate the Influence of Grassland Restoration Activities on Ecosystem Forage Provisioning Services

As valuation of ecosystem goods and services derived from ecological processes becomes increasingly important in environmental decision-making, the need to quantify how restoration activities influence ecosystem function has grown more urgent, particularly within income-generating or subsistence-providing landscapes where economic needs and biodiversity goals must be balanced. However, quantification of restoration effects is often hindered by logistical issues, which include (1) the difficulty of systematically monitoring responses over large areas and (2) lack or loss of comparison sites necessary for assessing treatment effect. We explored the use of remote sensing to quantify the effects of native grass seeding and prescribed burns on ecosystem forage provisioning services within a California (U.S.A.) rangeland landscape. We used Landsat time series to monitor forage (green biomass) dynamics within 296 ha of treatment areas—distributed throughout a 36-km² watershed—for 6 years and to identify post hoc comparison areas when a priori comparisons were lacking. Remote sensing analysis documented gains and losses in forage provisioning services due to restoration efforts and provided critical information for adaptive management. Our results demonstrate the degree to which invaded grasslands can be resistant to change and suggest that increasing the functional complexity of restoration mixes might help increase forage availability and reduce opportunities for weed reinvasion.     

Vertical transmission in feather mites: insights into its adaptive value

1. The consequences of symbiont transmission strategies are better understood than their adaptive causes. 2. Feather mites are permanent ectosymbionts of birds assumed to be transmitted mainly vertically from parents to offspring. The transmission of Proctophyllodes doleophyes Gaud (Astigmata, Proctophyllodidae) was studied in two European populations of pied flycatchers, Ficedula hypoleuca Pallas (Passeriformes, Muscicapidae). 3. The vertical transmission of this mite species is demonstrated here with an acaricide experiment. This study also compared (for two distant populations during 4 years) patterns in reductions in mite intensity in adult birds, from egg incubation to chick‐rearing periods, with the predictions of three hypotheses on how host survival prospects and mite intraspecific competition might drive feather mites' transmission strategy. 4. The results are in agreement with previous studies and show that feather mites transmit massively from parents to chicks. 5. The magnitude of the transmission was closer to that predicted by the hypothesis based on intraspecific competition, while a bet‐hedging strategy is also partially supported.     

Population structure,diversity, and phylogeography in the near‐threatened Eurasian black vultures Aegypius monachus (Falconiformes; Accipitridae) in Europe: insights from microsatellite and mitochondrial DNA variation

The Eurasian black vulture (Aegypius monachus) has experienced a severe decline during the last two centuries and is globally classified as near‐threatened. This has led to the extinction of many traditional breeding areas in Europe and resulted in the present patchy distribution (Iberian and Balkan peninsulas) in the Western Palearctic. In the present study, we describe the current genetic status of the European populations using both mitochondrial cytochrome b sequences and nuclear microsatellite markers, comparing with those found in Asia (Mongolia and Caucasus region). Although, mitochondrial (mt)DNA revealed a relatively low genetic variability (haplotype diversity), no evidence of genome‐wide genetic erosion exists because nuclear diversity exhibits normal levels and strong differentiation. A highly philopatric dispersal behaviour must be invoked to explain the existence of a clear pattern that revealed by the phylogeographic analysis, which indicates a sharp East–West clinal distribution and an allopatric differentiation. The distribution of mtDNA haplotypes one in the Iberian population and two in Balkan population and the significance divergence at nuclear loci fulfill the definitions of those populations as evolutionary significant units. We discuss how management strategies should aim at the maintenance (or increase) of current genetic variability levels, suggesting that independent conservation plans are urgently required to protect these two breeding European populations from extinction. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 859–872.     

栀子水提取物对实验性2型糖尿病大鼠血糖及同型半胱氨酸水平的影响

观察栀子提取物对实验性2型糖尿病大鼠血糖、血脂及同型半胱氨酸水平的影响.采用Wistar雄性大鼠70只,随机抽取10只作为正常对照组,喂以普通维持饲料,其余60只高糖高脂饲料喂养4周后,ip链脲佐菌素(STZ)30 mg/kg建立2型糖尿病模型,7d后选取成模大鼠50只随机分为模型对照组(生理盐水)、盐酸二甲双胍对照组、栀子提取物低、中、高剂量组(0.2、0.4、0.6 g/kg),每组10只.连续ig给药4周后,观察各组大鼠血糖、血脂及同型半胱氨酸水平等变化.栀子提取物ig能降低糖尿病大鼠的血糖、甘油三酯(TG)、胆固醇(TC)、低密度脂蛋白(LDLC),同时能升高高密度脂蛋白(HDLC),降低同型半胱氨酸水平.     

根据外部形态特征试论披碱草属3组植物间的系统关系

通过对披碱草属中小颖组、宽颖组和长颖组种类外部形态的观察,总结了3组植物外部形态特征的异同,探讨了形态学特征的分类学意义。同时,根据3组植物外部形态性状—花序、小穗、小花、以及内稃的演化趋势,分析了各组的演化关系和系统位置。结果表明：小颖组最原始,宽颖组较进化,长颖组最高级;小颖组可能直接派生了较进化的宽颖组,并在宽颖组的基础上进而产生了最高级的长颖组。此外,本文对披碱草属参试种的系统关系也作了一定程度的探讨,结果显示圆锥披碱草最原始,墨西哥披碱草最进化,其余参试种居于两者之间。上述研究工作为整个披碱草属系统与进化方面的探讨提供了形态学方面的理论证据。     

枯草芽孢杆菌C-D6对辣椒炭疽菌附着胞形成的抑制作用研究

【目的】研究枯草芽孢杆菌(Bacillus subtilis) C-D6菌株对辣椒炭疽菌(Colletotrichum capsici)附着胞形成的抑制作用,探索炭疽病生物防治的新途径。【方法】通过对峙培养测定C-D6菌株的抗菌活性,应用摇瓶培养结合生物测定筛选产生抗菌活性成分的最适培养基,采用硫酸铵分级沉淀、Sephadex G-75凝胶柱层析和阴离子交换层析对抗菌蛋白进行分离纯化,应用聚丙烯酰胺凝胶电泳测定蛋白分子量。【结果】C-D6菌株在PDA平板上对辣椒炭疽菌显示明显的抑制作用,其YPD培养液能完全抑制该菌的附着胞形成。摇瓶培养的结果显示C-D6菌株产生抗菌活性物质的最适培养基为YPD培养基。C-D6菌株在该培养基中培养14 h后,所形成的活性物质可完全抑制辣椒炭疽菌的附着胞形成。从该菌的YPD培养液中分离获得一个分子量为32 kD,能明显抑制辣椒炭疽菌附着胞形成的抗菌蛋白。【结论】C-D6菌株的生防特征显示该菌株对防治辣椒炭疽菌引起的炭疽病具有潜在的应用价值。