使用粪堆数量估计日本奄美群岛上琉球兔的种群数量

为了测量奄美岛上濒危物种琉球兔 (Pentalagusfurnessi)的丰盛度 ,我们计数了森林中道路、溪流和森林地被物中的粪堆数量。计算用的模型包括新粪堆的数量及其年龄、总粪堆数量、每天产生的平均粪堆数 ,以及在森林地被物和溪边的粪堆数量的回归方程。估计在 1 993- 1 994年期间该岛上有 2 5 0 0 - 6 1 0 0只琉球兔 ,在 2 0 0 2 - 2 0 0 3年间有 2 0 0 0 - 4 80 0只。通过比较粪便丰盛度和在森林道路旁观察到的琉球兔数量 ,我们考察了该模型的有效性 ,最后将以前调查的数据应用于该模型以确定种群下降的程度     

Calcium Deposition in Idioblasts of Mulberry Leaves

Large, rounded idioblasts were observed in adaxial leaves ofmulberry plants; they were clearly distinguishable from epidermal,trichome and parenchyma cells. The size and density of idioblastsvaried according to leaf age. Cytological features of idioblastswere as follows: the outermost region (‘cap’) ofidioblasts was situated on the adaxial surface as a dome-likeprotrusion; a cylindrical protuberance extended from the capregion to the inner part of the idioblast; in idioblasts frommature leaves a crystal mass was suspended from the lower tipof the cylindrical protuberance. Elemental analysis of idioblastsdemonstrated that silicon (Si) was localized in both the capregion and the cylindrical protuberance but calcium (Ca) waspresent in the large crystal, indicating site-specific cellularlocalization of Ca and Si within an idioblast. Histochemicalassays showed that a distinct Ca crystal filled the vacuolesof idioblasts in mature leaves, while immature leaves had manyidioblasts without Ca deposition. The increase in the Ca contentof leaves was directly proportional to the increase in leafage and appeared to be closely related to the Ca sink capacityof the developing idioblast vacuoles. The maximum sink capacitywas quantified to be approximately 40 ng per idioblast whenmulberry plants were grown hydroponically with excess Ca.Copyright1999 Annals of Botany Company Morus alba, idioblast, Ca deposition, Ca sink capacity, silicon, X-ray microanalysis, histochemistry, scanning electron microscopy.