981 resultados para 301.22
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1. Systematic list of birds (pp. 23-31) 2. Observations on the Galapagos fur seal, Arctocephalus australis galapagoensis Heller, 1904 (pp. 31-33) 3. Cetaceans observed (pp. 33-34)
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A meeting was convened on February 22-24, 2005 in Charleston, South Carolina to bring together researchers collaborating on the Bottlenose Dolphin Health and Risk Assessment (HERA) Project to review and discuss preliminary health-related findings from captured dolphins during 2003 and 2004 in the Indian River Lagoon (IRL), FL and Charleston (CHS), SC. Over 30 researchers with diverse research expertise representing government, academic and marine institutions participated in the 2-1/2 day meeting. The Bottlenose Dolphin HERA Project is a comprehensive, integrated, multi-disciplinary research program designed to assess environmental and anthropogenic stressors, as well as the health and long-term viability of Atlantic bottlenose dolphins (Tursiops truncatus). Standardized and comprehensive protocols are being used to evaluate dolphin health in the coastal ecosystems in the IRL and CHS. The Bottlenose Dolphin Health and Risk Assessment (HERA) Project was initiated in 2003 by Dr. Patricia Fair at the National Oceanic and Atmospheric Administration/National Ocean Service/Center for Coastal Environmental Health and Biomolecular Research and Dr. Gregory Bossart at the Harbor Branch Oceanographic Institution under NMFS Scientific Research Permit No. 998-1678-00 issued to Dr. Bossart. Towards this end, this study focuses on developing tools and techniques to better identify health threats to these dolphins, and to develop links to possible environmental stressors. Thus, the primary objective of the Dolphin HERA Project is to measure the overall health and as well as the potential health hazards for dolphin populations in the two sites by performing screening-level risk assessments using standardized methods. The screening-level assessment involves capture, sampling and release activities during which physical examinations are performed on dolphins and a suite of nonlethal morphologic and clinicopathologic parameters, to be used to develop indices of dolphin health, are collected. Thus far, standardized health assessments have been performed on 155 dolphins during capture-release studies conducted in Years 2003 and 2004 at the two sites. A major collaboration has been established involving numerous individuals and institutions, which provide the project with a broad assessment capability toward accomplishing the goals and objectives of this project.
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本文对神农架地区广泛分布的米心水青冈林和锐齿槲栎林的种群和群落学特征、干扰历史、更新策略、生物量、生产量及元素循环特征进行了研究。得到如下结论: 1 米心水青冈林是神农架地区山地垂直分布的地带性植被类型,主要群落学特征为:(1)建群种明显,该区域主要有2种类型,即米心水青冈林和米心水青冈、锐齿槲栎林;(2)群落结构简单,但物种组成丰富,在6600m~2样地中出现高等植物(不含苔藓植物)77科150属271种,组成种类以蔷薇科、百合科、忍冬科、虎耳草科、樟科、杜鹃花科和壳斗科为主;(3)群落乔木层(占重要值的12%)和灌木层(占盖度的15%)中含有一定比例的常绿树种;(4)群落生活型以高位芽植物(70.89%)占绝对优势,其次为地面芽植物(15.50%)和地下芽植物(12.92%)。 2 米心水青冈是多主干的树种,萌枝现象普遍,但萌枝数量不同地点差异较大。通过萌枝产生的枝群体平均密度为257 ± 99.3n•hm~(-2)。枝群体的年龄结构表现为“幼龄个体数目较多型”和“中国年龄阶段数目较多型”,并且有较多的枝群体表现出一致的年龄结构。从整个群落米心水青冈的年龄结构来看,表现出发展型种群的特点。枝群体的分布格局为随机分布。9丛米心水青冈完整的年轮分析结果表明,它们萌枝的时间不是边疆的,而与森林的受干扰有关。根据83个圆盘和生长锥芯资料,米心水青冈在萌枝后成长为乔木层或林冠层的过程中,径向生长表现为5种模式。这是丛株内竞争的结果。萌枝在米心水青冈林的维持和发展过程中,具有重要的生态学作用。 3 锐齿槲栎林是神农架地区山地垂地分布的地带性植被类型,主要群落学特征为:(1)建群种明显,该区域主要有2种类型,即锐齿槲栎林和锐齿槲栎、米心水青冈林;(2)群落乔木层和灌木层中含有一定比例的常绿树种,和暖温带的落叶栎林有较大差异;(3)群落物种组成丰富,不仅具有典型的温带科属,还有典型亚热带分布的科属,组成种类主要以蔷薇科、百合科、忍冬科、虎耳草科、山茱萸科、杜鹃花科、壳斗科和樟科;(4)生活型以高位芽植物(66.32%)占绝对优势,其次为地面芽(23.51%)和地下芽(9.47%)植物。 4 通过样地调查、树干解析及直径分析法,对米心水青冈林和锐齿槲栎林受压和释压历史及更新策略进行了研究。米心水青冈直径生长表现为5种模式。而锐齿槲栎只表现为2种模式。85.9 ± 6.9%的米心水青冈有过受压过程,平均受压2.1 ± 0.8次,平均受压时间为47 ± 24.1a,最长受压时间73a,平均释压次数为1.6 ± 0.7次,平均释压时间为23 ± 21.5a,而60.83%的锐齿槲栎都均有1次受压。平均受压时间为19 ± 14a,受压后没有表现出释压过程。结合高生长和径向生长,认为米心水青冈是耐阴树种,它的更新策略是在林下形成苗性萌枝,在有林窗形成时释压生长进入乔木层;而锐齿槲栎是不耐阴树种,它的更新策略是通过产生大量种子,当有大的林窗时,幼苗在林窗内生长逐步进入乔木层。 5 神农架地区102-130a成熟米心水青冈林的生物量在251.31-358.63T•hm~(-2)之间,平均为288.70 ± 48.30T•~(-2),20-60a锐齿槲栎林群落生物量在134.85-301.20T•hm~(-2),平均为231.60 ± 78.10T•hm~(-2)。虽然米心水青冈林和锐齿槲栎林灌木层草本层及藤本植物组成很丰富,但二种类型森林生物量的95%以上集中在乔木层。乔木层生物量主要集中在少数优势种中。在米心水青冈林生物量从大到小的序列中,前5种植物分别占乔木层总生物量58.67%-96.37%不等,同样锐齿槲栎林前5种植物占群落生物量的68.13%-95.26%。常绿植物占乔木层生物量的比例变化较大,米心水青冈林中占2.85-18.70%,锐齿槲栎林中一般常绿植物占0.8-9.98%,只有1个锐齿槲栎林样地常绿植物(主要是粉白杜鹃)占乔木层生物量的44.04%。米心水青冈林生物量根冠比为0.27 ± 0.05,锐齿槲栎林为0.21 ± 0.06。神农架地区米心水青冈林的生物量,在成熟的欧洲水青冈林及日本的水青冈林生物量范围之内,而锐齿槲栎林生物量远远大于我国温带落叶栎林的生物量。 6 神农架地区102-130a米心水青冈林生产量范围在1857-2786g•m~(-2)•a~(-1),平均为2330 ± 397 g•m~(-2)•a~(-1)。20-60a锐齿槲栎林的生产量范围在1319-2521 g•m~(-2)•a~(-1),平均为1930 ± 498 g•m~(-2)•a~(-1)。米心水青冈林和锐齿槲栎林乔木层生产量占群落总生产量的95%以上,乔木层各器官生产量大小顺序为叶> 树干> 枝和根,其中叶生产量占乔木层的一半以上,达53.87 ± 2.72%(米心水青冈林)和57.31 ± 6.23%(锐齿槲栎林)。在乔木层生产量从大到小的序列中,前5种植物平均占乔木层总生产量的81.03 ± 13.94%(米心水青冈林,范围在62.75%-92.66%)和84.23 ± 9.68%(锐齿槲栎林,范围在68.54-95.11%)。米心水青冈林和锐齿槲栎林群落地下部分生产量占总生产量的比例分别为11.29 ± 1.02%和9.22 ± 2.72。和我国其它地区地带性植被类型相比。米心水青冈林和锐齿槲栎生产量是较高的,和亚热带绿阔叶林生产量接近,但在器官分配上两者差异较大。 7 米心水青冈林和锐齿槲栎林土壤均呈酸性。其中锐齿槲栎林地土壤酸性更强。土壤元素特征表现为Al>C>K>Mg>Ca>N>S、P的特点,富铝化作用明显。8种元素在群落优势植物不同部位含量差异较大,N、P、K、Ca、Mg基本上是以叶片含量最高,树干或根中最低。仅从叶片来看,元素特征表现为C>Ca、N>K>Mg>S>P、Al。优势植物的C/N和C/P显著高于暖温带落叶阔叶林优势植物。8种元素在米心水青冈林和锐齿槲栎林中积累量分别为147.09 ± 25.60和116.00 ± 37.63 Mg hm~(-2)a~(-1),其中97%以上积累在群落乔木层。两种森林类型各元素的积累量都表现为C>Ca, N> K> Mg> P> S> Al的特点。米心水青风林和锐齿槲栎林8种元素的年存留量分别为6263 ± 90.8和5946 ±246 kg hm~(-2)a~(-1),其中N、P、K、Ca、Mg 5种主要营养元素的存留量分别为179.7 ± 18.2和169.4 ± 23.5kg hm~(-2) a~(-1)。两种森林类型各元素的存留量都表现为C> N> Ca> K> Mg> S> P> Al。