Altitudinal differences in bark stripping by sika deer in the subalpine coniferous forest of Mt. Fuji

Deer expansion is a growing concern for forest ecosystem management. In Japan, upward expansion to subalpine and alpine areas has reached alarming proportions in recent years. We examined bark stripping by sika deer along an altitudinal gradient in the subalpine coniferous forest at three altitude ranges (1800-2000 m, 2000-2200 m, and 2200-2400 m) on the southern slope of Mt. Fuji. We tested differences in densities and diameter at breast height (DBH) of trees and those with bark-stripped stems of all tree species among the three altitude ranges. Then, we compared the relative densities of deer, based on pellet counts, to determine the impact of deer in relation to deer use and forest stand patterns across the altitudinal range studied. The results of the study show that differences in bark stripping by sika deer depended largely on the elevation and the species. Larger stems were sparsely distributed in the lowest elevation zone between 1800 and 2000 m. The relative density of deer was highest in the areas exhibiting high bark-stripping intensity on small regenerating trees of the dominant coniferous species, Abies veitchii, and on broadleaf species. In the highest elevation zone between 2200 and 2400 m, smaller stems were densely distributed, and the relative deer density was lowest where the bark-stripping intensity on small stems was lower for all three species studied. The damage to subalpine tree stems corresponded to the availability of palatable tree species with a small diameter, as reflected by the successional stage along the elevational gradient of subalpine forest on Mt. Fuji. These results suggest that the continuous impact of bark stripping on the dominant tree species might cause severe changes in forest succession.     

Substitution of fish meal by soybean meal in diets for juvenile marbled spinefoot,Siganus rivulatus

The present work was performed to assess whether soybean meal (SBM) could replace fish meal (FM) as a source of dietary protein in diets of the marine herbivore Siganus rivulatus. Five iso-nitrogenous (40% protein) and iso-energetic (14 MJ/Kg) diets were prepared with SBM replacing fish meal at 0%, 25%, 50%, 75%, and 100% dietary protein. A 60-day feeding trial was conducted with 240 juvenile S. rivulatus (initial body mass 1.74 ± 0.03 g). Survival, growth, feed, and protein efficiency and hematological parameters were assessed. Growth correlated negatively with increase in dietary SBM. All production parameters measured were negatively affected at all levels of SBM inclusion. There were no effects on total or differential blood counts, hemoglobin, or plasma protein, but hematocrit values were negatively correlated with SBM addition. Results suggest that total replacement of FM by SBM without adding other supplements is not recommended, even for an herbivorous marine fish such as S. rivulatus.     

草食动物与植物之间协同进化研究

草食动物与植物之间存在协同进化关系。在环境的选择压力下,一方面植物为了逃避各类草食动物的采食而形成防御性的形态结构以及生理生态适应机制;另一方面,动物为了尽可能多地获得食物和满足营养需求,通过优化采食以提高其适合度。草食动物与植物之间的协同进化实际上也是自然界适者生存的＂军备竞赛＂,因而对物种进化产生重要影响。本文综述了草食动物与植物之间协同进化关系的研究进展,分析了协同进化的原因,并探讨其生态学意义。     

贵州省发展草食畜禽战略的研究

贵州省具有发展草食畜禽的优越条件,从省情出发,研究了贵州省养猪的最大承载量,研究了贵州自然条件、草食畜禽品种资源和饲料资源,研究了发展草食畜禽的潜力与措施,提出了贵州主要畜禽发展指标等。     

Effects of grazing by horses and/or cattle on the diversity of coastal grasslands in western France

In the coastal grasslands of western France, extensive mixed grazing by cattle and horses has been practised for many centuries. The vegetation of these old embanked grasslands varies along a topographical gradient with a hygrophilous plant community in low-lying depressions seasonally flooded, a mesophilous community on high level flats that are never flooded, and a meso-hygrophilous community on slopes where the soil remains saline. Recently, fewer horses have been grazed on these pastures and so a 6-year study was designed to investigate the effects of monospecific and mixed grazing by horses and cattle on plant community structure, composition and diversity. Mixed grazing produced the most species-rich and structurally diverse swards. Mixed grazing enhanced the development of rosette, sub-halophyte and halophyte species where the soil is saline, due to additive effects between the two herbivore species. Mixed grazing also limited the strongly competitive Elymus repens and Agrostis stolonifera on horse latrine areas, cattle grazing, thus showing a compensatory effect. The combination of additive and compensatory effects with mixed grazing could be used to manage plant diversity, heterogeneity in vegetation structure and communities of conservation value at the scale of the grassland ecosystem.     

慈竹ARF基因的鉴定及虫害胁迫下的表达

植物生长素响应因子(ARF)参与调节了植物的向性运动、子叶发育、胚胎形成、叶片器官衰老、维管束形成等,在植物生长发育过程发挥重要调控作用。为研究慈竹ARF基因家族及虫害胁迫下的表达,通过查询慈竹竹笋转录组数据库,分离出24个ARF基因家族成员。利用生物信息学方法分析,发现慈竹ARF家族序列保守,与毛竹亲缘性较近。通过对慈竹竹笋转录组中ARF基因表达模式分析发现,大部分ARF基因在竹笋中表达,少数ARF基因表达量在受到虫害胁迫后表达量发生显著变化。qRT-PCR结果表明,ARF基因在竹笋的几个部位在虫害胁迫后表达量均显著变化,推测其可能参与了竹笋对虫害胁迫响应,且在笋毛中表达量均升高,推测笋毛在抵御虫害胁迫中发挥了重要作用。     

草食动物散放区植被生长影响因素研究

草食动物散放区植被的生长情况一直是动物园行业比较关心的重要课题之一,植被生长的好坏将直接影响到游客的观赏效果。哈尔滨北方森林动物园自2004年搬迁到现址以来,一直对草食动物散放区的植被生长进行了比较系统的观察和研究,经过近7 a的实践和摸索,现在的3个散放区中非洲草食动物散放区和马散放区2个区植被生长非常好,而鹿散放区目前植被还没有恢复。通过研究认为散放区内的植被类型、单位面积上饲养动物的种类和数量以及降雨量是决定散放区植被生长情况的重要因素。     

寄主植物-害虫-天敌三营养层系统相互作用的上行控制

寄主植物-害虫-天敌三营养层相互作用的重要性、害虫数量被其天敌所调节（下行控制）、寄主植物的物理和化学特性直接和间接影响害虫和其天敌的多度及分布（上行控制）已是生态学界活跃的研究主题。在不同的陆地生态系统中,作为害虫种群数量控制因子,寄主植物资源的上行控制可能比天敌的下行控制更普遍。寄主植物的基础营养物质、诱导产生的次生代谢物质和形态特征影响害虫的生理和行为,依次决定害虫的生殖、寿命和存活,直接控制害虫种群数量动态;影响天敌的行为和适合度,间接控制害虫种群数量动态。     

The importance of nutrient hot-spots in the conservation and management of large wild mammalian herbivores in semi-arid savannas

Extensive studies in the Serengeti showed a strong link between patchy herbivory and forage quality, and the factors that determine forage patch selection at different scales have been evaluated in various models. The purpose of this study was to examine to what extent favoured forage patches in the Lowveld of South Africa are determined by forage quality and how important these are as forage resources. Understanding the factors that determine herbivore distribution will provide insights into how the utilization of forage by herbivores affects and is influenced by the ecosystem and thereby improve our abilities to conserve and manage these systems. The Kruger National Park is a large wildlife conservation area, with stratified rainfall and soil nutrient patterns. Tuft utilization and number of faecal deposits were used to determine favoured forage patches within these stratifications. On the low-nutrient granites, the use of grass tufts on the crests of hillslopes was about a quarter that on sodic sites, and a third of that of termite mounds. On the high-nutrient basalts, utilization of crests was about a third of that of termite mounds and about a quarter of the utilization of sodic sites in the wet and growth season, but towards the end of the dry season all patches were utilized to a similar extent. On sodic sites, shorter grass grazers accounted for almost ten times more faecal deposits than other species, although there was evidence of all the other large herbivore groups also utilizing these sites. The foliar nitrogen and phosphorus concentrations from termite mounds and sodic patches were up to twice that found on the crests in the wet season, especially on the granites, indicating that forage quality may indeed play an important role in determining favoured forage patches. Furthermore, only the patches on the sodic sites and termite mounds produced foliage of sufficient quality to support reproduction and maintenance of body condition. These patches thus form key resource areas that determine animal condition and hence dry season survival. These findings have important management consequences: firstly in predicting the number of animals that may be supported by an area; secondly, because these nutrient hot-spots are so intensely utilized by herbivores, they will be the first to show degradation, and monitoring programs should thus include these areas. Appropriate monitoring designs will detect degradation in these areas in time to take appropriate management actions that would avoid irreversible system changes.