Soil pH and organic matter content add explanatory power to Northern Lapwing Vanellus vanellus distribution models and suggest soil amendment as a conservation measure on upland farmland

Habitat associations of farmland birds are well studied, yet few have considered relationships between species distribution and soil properties. Charadriiform waders (shorebirds) depend upon penetrable soils, rich in invertebrate prey. Many species, such as the Northern Lapwing Vanellus vanellus, have undergone severe declines across Europe, despite being targeted by agri‐environment measures. This study assessed whether there were additive effects of soil variables (depth, pH and organic matter content) in explaining Lapwing distribution, after controlling for known habitat relationships, at 89 farmland sites across Scotland. The addition of these soil variables and their association with elevation improved model fit by 55%, in comparison with models containing only previously established habitat relationships. Lapwing density was greatest at sites at higher elevation, but only those with less peaty and less acidic soil. Lapwing distribution is being constrained between intensively managed lowland farmland with favourable soil conditions and upland sites where lower management intensity favours Lapwings but edaphic conditions limit their distribution. Trials of soil amendments such as liming are needed on higher elevation grassland sites to test whether they could contribute to conservation management for breeding Lapwings and other species of conservation concern that depend upon soil‐dwelling invertebrates in grassland soils, such as Eurasian Curlew Numenius arquata, Common Starling Sturnus vulgaris and Ring Ouzel Turdus torquatus. Results from such trials could support improvement and targeting of agri‐environment schemes and other conservation measures in upland grassland systems.     

Plant‐Inhabiting Ant Utilizes Chemical Cues for Host Discrimination

The Neotropical ant Pseudomyrmex triplarinus is involved in an obligate and complex symbiotic association with Triplaris americana trees. The ants inhabit trunk and branch domatia and respond aggressively to foreign invaders. Their degree of host specificity and basis for recognition of host trees has not been studied. We determined that, in contrast to T. americana seedlings, heterospecific seedlings set around the host trees suffered continuous pruning. Ants also removed 80–100 percent of heterospecific leaves attached to the trunk in contrast to only 10–30 percent of conspecific leaves. True species specificity was demonstrated by the selective removal of leaves from Triplaris poeppigiana pinned to host trees. This selectivity was also observed in a matrix‐independent bioassay using leaf cuticular extracts on glass microfiber strips. Strips treated with leaf wax extracts from host trees and pinned to the trunk of host trees received only 42 percent of the number of ant visits recorded on solvent‐treated controls by the end of the experiment. Strips treated with extracts of a related species, T. poeppigiana, received 64 percent of the number of ant visits compared with solvent‐treated controls. These experiments also suggest that P. triplarinus recognizes surface chemicals of their host tree, independent of the texture or architecture of the carrier material; although these factors may still play some role in recognition. This is the first study that we are aware of to investigate the mechanism of host discrimination related to pruning behavior. Abstract in Spanish is available at http://www.blackwell‐synergy.com/loi/btp .     

西藏珠穆朗玛峰国家级自然保护区哺乳动物区系及其垂直变化

珠穆朗玛峰国家级自然保护区保护着以世界最高峰为代表的极高山生态系统,在生态和生物的演化及保护中具有重要地位。受交通、自然环境等条件限制,外界对其哺乳动物区系的了解尚不完整。我们于2010 年9月至2012 年10 月在保护区的调查点内利用样带法、访问调查法、自动感应照相系统监测法和夹日法进行了5 次哺乳动物区系调察,共确认10 目23 科81 种。国家重点保护物种有34 种,占总数的42.0% ;地域特征明显,高地型17 种和喜马拉雅-横断山区型14 种,共占38. 3%。区内可以划分为6 个自然带,哺乳动物物种丰富度表现为随海拔先升高后降低,并以2 500 -3 300 m 的物种数最多,共48 种。区系组成南、北翼差异显著,南翼的76 种哺乳动物中,东洋界41 种,古北界25 种;而北翼的29 种中,东洋界仅2 种,古北界23 种。南翼3 300 m以下东洋界优势明显,而4 000 m 以上古北界则占绝对优势,据此我们认为保护区位于东洋界和古北界分界线上,且分界线在3 300 -4 000 m 之间为宜。     

沼泽交错带白桦——长白落叶松优势种群的年龄结构及其动态

采用径级结构替代年龄结构与建立种群年龄结构模型相结合的方法,研究沼泽交错带白桦—长白落叶松优势种群的年龄结构特征。结果表明:白桦、长白落叶松和辽东桤木种群的年龄结构呈纺锤型,龄级—个体数间的关系可用Lognormal函数表征;种群动态量化指数V'_(pi)为辽东桤木(9.57%)白桦(4.02%)长白落叶松(1.83%),均趋近于0,说明种群处于稳定型向衰退型过渡阶段;白桦、长白落叶松及辽东桤木种群幼龄个体严重不足,白桦和辽东桤木种群的存活曲线趋于Odum-B3型,而长白落叶松种群趋于Deevey-I型。白桦、长白落叶松及辽东桤木种群具有前期增长、中后期衰退的特征;白桦、长白落叶松和辽东桤木种群数量受基波影响显著,种群整个生活史阶段未显现小周期波动,种群发展较稳定;随着时间的推移,在未来2、4和6个龄级后,白桦、长白落叶松和辽东桤木种群老龄个体数均有增加,但由于更新幼苗个体稀少,未来必然呈衰退趋势。森林—沼泽交错带的白桦、长白落叶松及辽东桤木种群对外界环境变化有强烈的敏感性和脆弱性,人类活动扰动会影响其发育与演变,从而提高了森林—沼泽交错带地区沼泽化的风险。因此,应减少人类活动对森林—沼泽交错带的干扰,加强对这一地区植被群落的保护与管理。     

典型阔叶红松林干扰历史重建及干扰形成机制

该文依托于小兴安岭典型阔叶红松(Pinus koraiensis)林9 hm²森林动态监测样地, 对样地内林窗边缘主要树种红松和臭冷杉(Abies nephrolepis)进行生长释放判定分析, 重建了冠层树木的干扰历史。结果表明: 整体上林窗木与非林窗木的生长变化百分率变化规律基本一致, 而不同林窗间生长变化百分率存在明显的差异, 林窗干扰及其产生的影响存在较大的变异性。在1733-1738、1748-1752、1769-1771、1798-1801、1827-1833、1841-1844、1935-1939及1968-1973年间红松生长释放较强, 其中1752、1770、1800、1830、1842、1937及1970年出现了明显的干扰峰; 在1889-1904、1932-1938、1947-1973和1986-2005年间臭冷杉生长释放较强, 其中1894、1934、1951、1968和1990年出现了明显的干扰峰。红松干扰存在2.0 a、3.5 a、3.8 a、7.3-7.9 a和9.1-18.2 a的显著周期, 臭冷杉干扰存在3.5-3.6 a、7.5-48.8 a和65-85 a的显著周期。风干扰是典型阔叶红松林干扰释放的主要因子, 异常温度也影响该地区树木生长释放事件。太阳活动通过影响局地风速、温度、降水等气候因子以及其他大尺度气候模态影响林窗动态, 可能是小兴安岭典型阔叶红松林的干扰机制之一。     

新疆艾比湖湿地自然保护区胡杨根系水分再分配的估算

根据对新疆艾比湖湿地自然保护区荒漠河岸林的主要建群种胡杨(Populus euphratica)的根系分布特征, 林冠下土壤的饱和容积含水量、最大导水率和根系最大导水率的试验观测数据, 以及对其林冠下5层不同深度土壤容积含水量、土壤水势的动态监测数据, 构建了胡杨根系水分再分配量估算的Ryel模型, 并对胡杨不同季节的水分再分配过程进行了短期模拟。结果表明: (1)胡杨根系水分再分配过程的水分再分配量的最大值出现在艾比湖地方时间凌晨2:30。(2)随着生长季节的变化, 胡杨根系水分再分配的作用逐渐减弱, 并表现出向土壤下层迁移的现象。6月份, 水分再分配过程主要发生在0-40 cm土层, 最大分配量为0.022 0 cm, 夜间总分配量为0.111 0 cm; 8月份水分再分配过程主要发生在10-70 cm土层, 最大分配量为0.006 5 cm, 夜间总分配量为0.018 4 cm; 10月份水分再分配过程主要发生在70-100 cm土层, 最大分配量为0.003 9 cm, 夜间总分配量为0.008 6 cm。     

四川美姑大风顶自然保护区两栖爬行动物资源调查

20 0 2年 8月 1日～ 17日对四川美姑大风顶自然保护区的两栖爬行动物进行了调查。结合前人的工作 ,该保护区共有两栖爬行动物 2 2种 ,其中两栖动物 11种 ,隶属于 9属 7科 2目 ,爬行动物 11种 ,隶属于 9属 4科 2亚目 1目。区系特点为 :(1)物种组成较丰富 ;(2 )都属于东洋界物种 ,没有古北界的成分 ;(3)区系组成较简单 ,以喜马控雅 -横断山区型和南中国型为主 ;(4 )特有种所占比例高。 (5 )既古老又具年轻的特点。美姑县新纪录 6种 ,大凉疣螈为国家Ⅱ级重点保护野生动物 ,横斑锦蛇为四川省重点保护野生动物。美姑大风顶自然保护区两栖爬行动物物种多样性和生境多样性较高 ,对于生物多样性保护和研究横断山脉两栖爬行动物物种组成及区系特征具有一定意义。     

湖北沉湖自然保护区鸟类多样性研究

根据1981-2003年的调查,记录沉湖自然保护区鸟类133种,隶属15日39科78属,占湖北省鸟类种数456种的29．2%,其中,湿地水禽84种,占63．2%,隶属7日17科43属。国家重点保护鸟类26种(其中Ⅰ级8种,Ⅱ级18种),列入世界自然保护联盟红皮书名录12种,列入中国濒危动物红皮书名录16种,列入CITES附录19种。其中,东方白鹳、白琵鹭和白头鹤的种群数量超过全球地理种群数量的1%。