999 resultados para Regeneration strategy
Resumo:
This report describes a surveillance strategy to detect deepwater invasive species in the Northwestern Hawaiian Islands. A need for this strategy was identified in the Papahānaumokuākea Marine National Monument Management Plan and the Monument’s Draft Natural Resources Science Plan. This strategy focuses on detecting two species of concern, the octocoral Carijoa riisei and the red alga Hypnea musciformis. Most research on invasive species in the Hawaiian archipelago has focused on shallow water habitats within the limits of conventional SCUBA (0-30 m). Deeper habitats such as mesophotic reefs are much more difficult to access and consequently little is known about the distribution of deepwater invasive species or their impacts. Recent deepwater (>30 m) sightings of H. musciformis and C. riisei, in and near NWHI, respectively, have prompted a call for further research and surveillance of invasive species in deepwater habitats. This report compiles the most up to date information about these two species of concern in deepwater habitats. A literature search and conversations with subject matter experts was used to identify their current distribution, preferred habitat types, optimal detection methods and ways to efficiently sample the vast extent of NWHI. The proposed sampling strategy prioritizes survey effort where C. riisei and H. musciformis are most likely to be found. At coarse spatial scales (tens to hundreds of kilometers), opportunistic observations and distance from the Main Hawaiian Islands, a principal propagule source, are used to identify high-risk islands and banks. At fine spatial scales (meters to tens of kilometers) a habitat suitability model was developed to identify high-risk habitats. The habitat suitability model focused on habitat preferences of C. riisei, since the species is well studied and adequate data exists to map habitats. There was insufficient information to identify suitable habitat for H. muscifomis. Habitat preferences for the algae are poorly understood and there is a lack of data at relevant spatial scales to map those preferences which are known. The principal habitats identified by the habitat suitability model were ledges and the edges of rugose coral reefs, where the shade loving octocoral would likely be found. Habitat suitability maps were developed for seven atolls and banks to aid in survey site selection. The protocol relied on technical divers to conduct visual surveys of benthic habitats. It was developed to increase the efficiency of surveys, maximize the probability of detection, identify important information relevant to future surveys and standardize results. The strategy, model and protocol were tested during a field mission in 2009 at several atolls and islands in NWHI. The field mission did not detect any invasive species among deepwater habitats and much was learned to improve future surveys. Data gaps and improvements are discussed.
Resumo:
The intent of this field mission was to continue ongoing efforts: (1) to spatially characterize and monitor the distribution, abundance and size of both reef fishes and conch within and around the waters of the Virgin Islands National Park (VIIS) and newly established Virgin Islands Coral Reef National Monument (VICR), (2) to correlate this information to in-situ data collected on associated habitat parameters, (3) to use this information to establish the knowledge base necessary for enacting management decisions in a spatial setting and to establish the efficacy of those management decisions. This work is supported by the National Park Service and NOAA’s Coral Reef Conservation Program’s Caribbean Coral Reef Ecosystem Monitoring Project.
Resumo:
The intent of this field mission was to continue ongoing efforts: (1) to spatially characterize and monitor the distribution, abundance and size of both reef fishes and conch within and around the waters of the Virgin Islands National Park (VIIS) and newly established Virgin Islands Coral Reef National Monument (VICR), (2) to correlate this information to in-situ data collected on associated habitat parameters, (3) to use this information to establish the knowledge base necessary for enacting management decisions in a spatial setting and to establish the efficacy of those management decisions. This work is supported by the National Park Service and NOAA’s Coral Reef Conservation Program’s Caribbean Coral Reef Ecosystem Monitoring Project. The report highlights the successes of this mission.
Resumo:
On July 12-15, 2008, researchers and resource managers met in Jupiter, Florida to discuss and review the state of knowledge regarding mesophotic coral ecosystems, develop a working definition for these ecosystems, identify critical resource management information needs, and develop a Mesophotic Coral Ecosystems Research Strategy to assist the U.S. National Oceanic and Atmospheric Administration (NOAA) and other agencies and institutions in their research prioritization and strategic planning for mesophotic coral ecosystems. Workshop participants included representatives from international, Federal, and state governments; academia; and nongovernmental organizations. The Mesophotic Coral Ecosystems Workshop was hosted by the Perry Institute for Marine Science (PIMS) and organized by NOAA and the U.S. Geological Survey (USGS). The workshop goals, objectives, schedule, and products were governed by a Steering Committee consisting of members from NOAA (National Centers for Coastal Ocean Science’s Center for Sponsored Coastal Ocean Research, the Office of Ocean Exploration and Research’s NOAA Undersea Research Program, and the National Marine Fisheries Service), USGS, PIMS, the Caribbean Coral Reef Institute, and the Bishop Museum.
Resumo:
Queen conch (Strombus gigas) stocks in the Florida Keys once supported commercial and recreational fisheries, but overharvesting has decimated this once abundant snail. Despite a ban on harvesting this species since 1985, the local conch population has not recovered. In addition, previous work has reported that conch located in nearshore Keys waters are incapable of spawning because of poor gonadal condition, although reproduction does occur offshore. Queen conch in other areas undergo ontogenetic migrations from shallow, nearshore sites to offshore habitats, but conch in the Florida Keys are prevented from doing so by Hawk Channel. The present study was initiated to determine the potential of translocating nonspawning nearshore conch to offshore sites in order to augment the spawning stock. We translocated adult conch from two nearshore sites to two offshore sites. Histological examinations at the initiation of this study confirmed that nearshore conch were incapable of reproduction, whereas offshore conch had normal gonads and thus were able to reproduce. The gonads of nearshore females were in worse condition than those of nearshore males. However, the gonadal condition of the translocated nearshore conch improved, and these animals began spawning after three months offshore. This finding suggests that some component of the nearshore environment (e.g., pollutants, temperature extremes, poor food or habitat quality) disrupts reproduction in conch, but that removal of nearshore animals to suitable offshore habitat can restore reproductive viability. These results indicate that translocations are preferable to releasing hatchery-reared juveniles because they are more cost-effective, result in a more rapid increase in reproductive output, and maintain the genetic integrity of the wild stock. Therefore, translocating nearshore conch to offshore spawning aggregations may be the key to expediting the recovery of queen conch stocks in the Florida Keys.
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摘要 神农架有着丰富的生物多样性和相对完整的森林生态系统,锐齿槲栎(Quercus aliena var. acuteserrata)是该地区落叶阔叶林重要的建群种之一,是其山地植被垂直带上的一个重要类型,对维持生态系统的稳定和水土保持具有重要意义。本论文主要研究了影响锐齿槲栎种群更新的一些重要因素以及探讨了神农架地区生物多样性的保护对策。 锐齿槲栎种子雨时空分布格局的研究结果表明:不同样地间种子雨的密度差别很大。树木的不同空间方位及种子的不同性状(被昆虫侵害、未发育成熟和有活力)在种子雨密度上的差异都极其显著。但在所研究的距离范围内(2-6m),与母株的距离对种子雨的密度影响不明显。相关性分析显示,样地中的种子雨空间分布与幼苗分布没有直接关系。实验中还发现,被昆虫侵害的种子较早下落,种子雨与落叶时间的不同步性有利于锐齿槲栎幼苗的建成。锐齿槲栎种群的结实存在明显的大小年现象,其结实周期约为2年。 动物对种子的散布与传播是影响锐齿槲栎种群更新的重要因素。在研究小型啮齿目动物对锐齿槲栎种子传播影响的实验中,用样方内布置铁夹的方法共捕获8种小型啮齿目动物,隶属3科、4属。实验结果还证明,不同林型和不同时间段(种子下落高峰期和种子基本落完时期)内小型啮齿目动物的捕食活动规律不同,林下灌木层类型对动物取食橡子和搬运距离也有一定的影响。 光对锐齿槲栎幼苗更新影响的研究结果表明,锐齿槲栎在林窗及林下都有大量的幼苗,而其幼树却很少。坡向对锐齿槲栎种群的更新有重要影响,光照好的东南坡上的更新情况明显比光照较少的西北坡好。光照梯度处理实验证明,光照强度影响锐齿槲栎幼苗的资源分配方式和比例,一定的遮荫环境更有利于锐齿槲栎幼苗的生长。 米心水青冈林(Fagus engleriana)和锐齿槲栎林在神农架地区广泛分布,两者分布的海拔范围比较相近,并形成一定面积的混交林。通过典型样地调查以及对苗木光合作用与资源分配的研究,结果表明:这两个树种具有不同的光利用策略,米心水青冈比较耐荫,林下更新较好,而锐齿槲栎林下更新不良,在光照较好的林窗下及次生裸地上更易更新。 神农架保护区是我国建立较早的以保护森林生态系统为主的自然保护区,是是联合国人与生物圈的保护地区之一,具有重要的生态价值和科研价值。保护区的建立对该地区的生物多样性保护发挥了重要的作用,但仍然面临着种种威胁。通过对神农架自然保护区当地社区的基本情况进行实地调查,分析结果表明,当地社区经济发展与生物多样性保护的矛盾比较突出,人类活动的干扰使景观破碎化呈增加趋势,整个生态系统比较脆弱。针对以上种种问题,建议加快制定有关保护区管理的法律;建立国家生态效益的补偿机制;推动实施社区共管;加强科研与区域生物多样性保护网络的协作;发展特色经济;加强能力建设,促进当地社区社会经济的全面发展。
Resumo:
1.对四川省岷江上游地区(茂县)的锐齿槲栎(Quercus aliena var. acuteserrata)天然次生林进行研究,发现:(1) 坚果完好比例约在14% ~26%之间,完好坚果的发芽率和发芽势都比较高,但在天然状况下能够留存到翌年5月的坚果几乎没有。因此,实生幼苗的天然补充就受到了严重的限制。(2) 林缘的幼苗密度低于所有其它生境的 (P<0.05),林中的幼苗密度最高,和林窗的比较有显著差异(P<0.05), 而和灌丛的比较则差异不显著(P>0.05)。在灌丛幼苗密度和林中以及林窗的比较都没有差异。动物对坚果的取食速度则是林中的最慢 (10.0%),林窗和林缘的基本相同(分别为61.1%和66.5%),取食速度都明显快于林中(P<0.01)。(3) 林中的幼苗在小于100 cm的各高度内都有大量分布,说明在林中树冠下幼苗是可以长期存在的,暗示在幼苗阶段的锐齿槲栎可能是耐荫的。(4) 在林中缺失幼树,在林缘则有包括幼树在内的完整的更新大小系列,表明林缘是更新的关键地点。(5) 在栎林的每一个大小级别上,萌生个体和实生个体都按各种比例伴生,说明导致萌生的干扰一直在发生,并可能在森林的更新中扮演重要角色;也说明该地区的锐齿槲栎林由萌生和实生起源的个体混合组成。 2.栎林是北半球温带森林的重要组成部分,因此栎林更新是全球森林更新研究的热点之一,而啮齿动物对栎林更新的影响则是关注的焦点。在2002~2003年,通过坚果标记研究了未被取食和遗弃坚果(即咬开后只有少部分被捕食后丢弃在林中的坚果)的健康比例,并定量测定了坚果的捕食、搬运、遗弃、丢弃、贮藏和留存等各种命运的比例和特点;对坚果也进行了各种人为的处理,以观测其命运和动物取食速度,发现:(1) 遗弃坚果中不健康坚果的比例比动物未取食的天然坚果中的比例有极显著的增加 (P>0.05),暗示啮齿动物一般是通过咬开坚果来识别坚果健康与否并决定是否捕食。(2) 根据坚果命运和对照相比改变与否以及如何改变,各种人工处理坚果的命运可以分为 4 类:① 坚果命运没有任何显著改变;② 坚果被就地捕食的速度降低,搬运的速度不变,最终搬运坚果的比例增加而就地捕食坚果的比例降低,留存坚果的比例偶尔能增加至0.2%;③ 坚果就地捕食的速度几乎降至0,搬运的速度则在下降一段时间后又上升,并且搬运作用持续了相对长的时间,最终搬运坚果的比例大大增加,就地捕食坚果的比例很低,留存率为0;④ 坚果被搬运和就地捕食的速度和比例都降低,留存坚果的比例相应的大大增加,甚至可以达到50%。(3) 命运得到显著改变的②、③、④类坚果所承受的人工处理按照作用方式又可以分为主要作用于坚果化学状态(即气味浓度)的处理、主要作用于坚果物理状态(颜色、形态、有无附属物等)的处理以及使坚果处于不同颜色背景的处理;其中主要作用于坚果化学状态的处理对坚果命运具有最重大的改变,如胶带包裹处理和烧焦处理;其它各种主要作用于坚果的物理状态和所处背景的处理对其命运则也具有相对轻微的改变。这一试验结果可能证明:啮齿动物在对坚果进行识别和取食选择等活动时主要依赖于嗅觉来感知坚果的可食性,但是能感觉物理状态和所处背景的视觉也起一定程度的作用。(4) 啮齿动物对栎树坚果进行就地捕食、遗弃、搬运、异地捕食、丢弃、贮藏等作用,使各种命运的坚果都具有一定的数量比例和特点,也提供了动物影响栎林更新的多种可能途径。 3.人工干扰是任何退化生态系统中都始终存在的重大问题。除了明显的砍伐或者采摘外,人工践踏也是一种重要的干扰,特别是在茂县的山林普遍被牛马不断的放牧的情况下,这个干扰的后果就更加显著。为此研究了人脚踩踏的路上的白车轴草和未踩踏草坪上白车轴草在最大叶长、株高、芽高、构件数量、构件平均鲜重、死叶数量、根长等构型指标,根、茎、叶三者的生物量(干重)及比例等生物量指标,平均花序数量、花平均数量等繁殖指标方面的不同,发现踩踏使白车轴草植株:(1) 株高降低,芽高降低,最大叶长变小,平均每厘米的构件数量增加,构件平均鲜重降低,根长度减小,死叶数量增加。(2) 平均花序数量下降,每花序的花平均数量下降。(3) 但是在生物量的分配上,根和茎的生物量没有显著的下降,但是叶的生物量显著减低。因为白车轴草的茎可以不断克隆繁殖,所以踩踏对其存活可能没有太大的影响,只是造成了植株的矮化和密集化,根也变短;但是对种子繁殖有重大影响,反映在平均花序数量和每花序平均花数的显著下降上。在生物量的分配中,作为主要的同化器官,叶的生物量显著下降,而根茎比没有变化。这可能说明这样的克隆植物其物质流动是呈现网络化的特征,具有比较强的抗干扰能力。 4.连香树、油松、日本落叶松、华山松油松混合林是茂县地区的几种主要的已经营造的林型或者树种。为了了解其20年来的营林效果,运用样方调查的方法测量了这几种树种或者林型的胸径、持水量、凋落物现存量、密度等,评价了它们在生长、营业循环和水土保持等方面的差异。结果表明:日本落叶松具有生长缓慢,凋落物现存量大,涵养水分能力良好的树种,值得推广;油松生长迅速,凋落物现存量巨大,涵养水分能力一般的树种,也可以大力栽植;油松和华山松的混交林具有比较大的蓄积量和较好的涵养水分的能力,可以推广;而连香树则做为生长速度中等,成材率低,凋落物现存量小,涵养水分能力差的树种,不应该进一步推广。
Resumo:
In tropical countries like India, climatic conditions vary in different parts, as a result the breeding of fast growing species such as Catla and silver carps poses considerable problems due to erratic or late monsoon or prolonged dry spell. Hence it is not possible to meet the fish seed requirement of the country. Therefore: to meet the future requirement and to over-come the environmental conditions a Modern carp Hatchery CIFE D-81 was designed. The system provides optimum temperature, silt free clean, cool, highly oxygenated water, low current and continuous removal of metabolites. It has been successfully demonstrated at Rawatbhata (Rajasthan), Badkhal (Haryana), Badbhada (M.P), Guntur and East Godavari District (A.P). Recently a Modern Carp Hatchery was installed in a semi-arid zone, Damdama (Haryana), during 1984, where it has produced record 1.88 crores of fish seed and worked successfully.