Landscape Zonation, benefit functions and target-based planning: Unifying reserve selection strategies   总被引：1，自引：0，他引：1  

Atte Moilanen 《Biological conservation》2007,134(4):571-579

The most widespread reserve selection strategy is target-based planning, as specified under the framework of systematic conservation planning. Targets are given for the representation levels of biodiversity features, and site selection algorithms are employed to either meet the targets with least cost (the minimum set formulation) or to maximize the number of targets met with a given resource (maximum coverage). Benefit functions are another recent approach to reserve selection. In the benefit function framework the objective is to maximize the value of the reserve network, however value is defined. In one benefit function formulation value is a sum over species-specific values, and species-specific value is an increasing function of representation. This benefit function approach is computationally convenient, but because it allows free tradeoffs between species, it essentially makes the assumption that species are acting as surrogates, or samples from a larger regional species pool. The Zonation algorithm is a recent computational method that produces a hierarchy of conservation priority through the landscape. This hierarchy is produced via iterative removal of selection units (cells) using the criterion of least marginal loss of conservation value to decide which cell to remove next. The first variant of Zonation, here called core-area Zonation, has a characteristic of emphasizing core-areas of all species. Here I separate the Zonation meta-algorithm from the cell removal rule, the definition of marginal loss of conservation value utilized inside the algorithm. I show how additive benefit functions and target-based planning can be implemented into the Zonation framework via the use of particular kinds of cell removal rules. The core-area, additive benefit function and targeting benefit function variants of Zonation have interesting conceptual differences in how they treat and trade off between species in the planning process.  相似文献   

Genetic analysis of resistance to spot blotch disease in wheat (Triticum aestivum L.) in Zambia     

Batiseba Tembo  Julia Sibiya  Pangirayi Tongoona  Rob Melis 《Journal of Crop Improvement》2017,31(5):712-726

Understanding the genetics of resistance to spot blotch disease, caused by Bipolaris sorokiniana (Sacc.) Shoem, is important to design an appropriate breeding strategy to improve the trait. The objective of this study was to determine the gene action and mode of inheritance of resistance to spot blotch in wheat. Eight genotypes with varying resistance to the disease were crossed in a full diallel mating design. Parents and their progenies were evaluated for spot blotch resistance. Data were analyzed using Hayman’s diallel analysis. The results suggested the importance of additive gene effects in controlling the resistance to spot blotch in the materials under study. No epistasis, maternal, or reciprocal effects were detected. Resistance to spot blotch exhibited partial dominance. Therefore, exercising selection for resistance in the early segregating generation should be an effective approach because of the predominance of additive gene effects. The Wr/Vr graph showed that the parents 30SAWSN5 (P3) and Coucal (P4) possessed more dominant genes, which makes them particularly suitable for inclusion in breeding for resistance to spot blotch.  相似文献   

抗热应激添加剂对蛋鸡生产性能的影响     

李锦春  陈少华  马伏灵 《安徽农业科学》2000,28(3):368-369

应用抗热应激添加剂在夏季高温 ( 2 9.5℃以上 )条件下对 43 2羽 2 60日龄的新罗曼褐产蛋鸡群进行分组防制试验 ,结果显示 :抗热应激添加剂Ⅰ号能显著提高产蛋率 (P <0 .0 5 ) ,极显著增加平均每枚蛋重 (P <0 .0 1) ,极显著降低破蛋率 (P <0 .0 1)及平均料蛋比 ,可以认为是一种效果良好的添加剂  相似文献   

Characterizing environmental and spatial variables associated with the incidental catch of olive ridley (Lepidochelys olivacea) in the Eastern Tropical Pacific purse‐seine fishery          下载免费PDF全文

Jose T. Montero  Raul O. Martinez‐Rincon  Selina S. Heppell  Martin Hall  Michael Ewal 《Fisheries Oceanography》2016,25(1):1-14

In the Eastern Tropical Pacific (ETP), a region of high fishing activity, olive ridley (Lepidochelis olivacea) and other sea turtles are accidentally caught in fishing nets with tuna and other animals. To date, the interaction between fishing activity, ocean conditions and sea turtle incidental catch in the ETP has been described and quantified, but the factors leading to the interaction of olive ridleys and fishing activity are not well understood. This information is essential for the development of future management strategies that avoid bycatch and incidental captures of sea turtles. We used Generalized additive models (GAM) to analyze the relationship between olive ridley incidental catch per unit effort (iCPUE) in the ETP purse‐seine fisheries and environmental conditions, geographic extent and fishing set type (associated with dolphins, floating objects or in free‐swimming tuna schools). Our results suggest that water temperature, set type and geographic location (latitude, longitude and distance to nesting beaches) are the most important predictor variables to describe the probability of a capture event, with the highest iCPUE observed in sets made over floating objects. With the environmental predictors used, sea surface temperatures (SST) of 26–30°C and chlorophyll‐a (chl‐a) concentrations <0.36 mg m^?3 were associated with the highest probability of an incidental catch. Temporally, the highest probability of an incidental catch was observed in the second half of the year (June to December). Four regions were observed as high incidental catch hotspots: North and south of the equator between 0–10°N; 0–10°S and from 120 to 140°W; and along the Colombian coast and surrounding regions.  相似文献   

玉米自交系株型和产量性状的关系及其利用研究   总被引：1，自引：2，他引：1       下载免费PDF全文

王雅萍 《玉米科学》2004,12(3):047-049

以15个自交系为材料,按P(P-1)/2双列杂交设计,研究了株型和产量性状的遗传与相关.结果表明,近年育成的自交系,一般配合力有一定的改进,产量性状的一般配合力有明显的提高,各性状的一般配合力在亲本间存在显著差异.产量的一般配合力与单株叶数和穗粗的一般配合力存在极显著正相关。  相似文献   

JX生物调理剂饲喂肉猪试验     

江立方  郁金观  伍勤观  王金福  顾剑新  施志刚 《家畜生态》2006,(6)

供试肉猪78头,随机分为三组,对照组(空白)、试验1组(新霉素115mg/kg、喹乙醇100mg/kg、阿散酸100mg/kg)、试验2组(JX调理剂0.2%),试验结果表明:第一阶段:试验1、2期末重,分别比对照组高1.34kg、1.07kg(P<0.05),试验组间差异不显著(P>0.05);第二阶段:试验1组期末重,比对照组高2.65kg(P>0.05),试验2组期未重比对照组高3.23kg(P<0.05),试验组间差异不显著(P>0.05);试验组料肉比均低于对照组,试验2组最低,比对照组降低0.2,饲料转化效率提高8.97%;试验2组比对照组每头猪多盈利48.8元,比试验1组多盈利10.28元;粪便中氮、磷含量试验2组明显下降,药物残留试验2组、对照组没有检出,试验1组猪肝阳性3个加、肉中阳性1个加。  相似文献   

生物试验的二次回归正交试验的模糊处理   总被引：3，自引：1，他引：2  

杨焕民  贾永全 《黑龙江八一农垦大学学报》1998,10(2):55-58

通过抗寒促生长剂对雏鸡生长，成活效果的试验，采用模糊处理方法，来探讨具有多项试验结果指标的二次回归正交试验设计的结果处理方法。  相似文献   

外加剂混凝土耐久性的试验研究     

刘淑萍 《森林工程》2002,18(2):36-38

本文针对掺加不同外加剂的混凝土的含气量、抗冻性能、抗压强度、抗折强度等方面的试验研究，提出掺入外加剂是提高水泥混凝土路面耐久性的必要措施。  相似文献   

Hydration behavior and compressive strength of cement mixed with exploded wood fiber strand obtained by the water-vapor explosion process     

Yi Min Wei  Bunichiro Tomita  Yasushi Hiramatsu  Atsushi Miyatake  Tsuyoshi Fujii  Tomoyuki Fujii  Shuichiro Yoshinaga 《Journal of Wood Science》2003,49(4):317-326

Poor compatibility was found between exploded wood fiber strand (WFS) and cement due to the excessive presence of water-soluble degraded polysaccharides in extractives of exploded WFS obtained from weathered wood waste treated by the water-vapor explosion process (WVEP). This study presents some comparative results from a continuing investigation on the compressive strengths of exploded WFS–cement mixtures. Based on results previously obtained with the hydration test, the relation between hydration behavior and compressive strength of the mixture was explored. In addition, the effect of the curing age on compressive strength development of the mixture with selected additive chemicals was examined. The results supported the results of early studies with hydration tests indicating that adding MgCl₂ to the mixtures of exploded WFS mixed with quick-curing cement or ordinary Portland cement and a composite of MgCl₂ + CaO added to the mixture of exploded WFS and furnace-slag cement effectively improved the hydration behaviors; it greatly enhanced the compressive strengths of mixtures as well. Compressive strengths were strongly correlated to maximum hydration temperatures (T_max) of wood–cement mixtures influenced by the cement type, wood wastes (treated or not with WVEP), additive chemicals, and their content levels. The results also indicated that adding selected chemicals had no significant effect on compressive strength among the mixtures of exploded WFS mixed, respectively, with three types of cement at a curing age of 180 days. X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy were used to identify the hydration products and to probe the element distribution of the mixture in the wood–cement interface zone from a fractured surface.Part of this report was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002  相似文献   

肉鸭3～7周龄预混料及全价饲料优化配方研究     

李焕友  姚武群  田萍  张云琦  朱锦兰  胡文娥  黄德纯  潘杏荷 《畜禽业》2001,(3):22-24

本研究在“肉鸭3～7周龄基础日粮优化配方研究”的基础上，将筛选出的肉鸭3～7周龄2套基础日粮优化配方与3套不同类型的预混料配方进行组合，进行饲养试验与屠宰测定，观察肉鸭的生长速度、饲料报酬、成活率、单位增重饲料成本、屠体品质等性状。结果显示：本试验设计的预混料配方Ⅲ是肉鸭3～7周龄预混料优化配方，优化基础配方Ⅰ与预混料配方Ⅲ、Ⅱ的组合均为肉鸭3～7周龄全价饲料优化配方。  相似文献