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991.
首次详细记录了鹞落坪国家级自然保护区模式地植物及其命名过程,并介绍保护区内具有较高观赏价值的乡土木本植物186种,隶属于53科104属,其中观花树木类50种;观形树木类37种;观果树木类18种;观叶树木类15种;树桩盆景与盆花类15种;行道树类21种;垂直绿化类25种;观赏竹类5种。对观赏特性和园林用途进行了初步探讨,以期为城市绿化及相关研究与资源利用提供参考。 相似文献
992.
蔷薇科是历山自然保护区种子植物的第一大科。该区有蔷薇科植物4亚科,23属,85种(含变种7)。在历山蔷薇科植物的区系组成中,优势属明显,尤以中等属突出,中等属占其蔷薇科植物总属数的43.48%,所含种数占该区蔷薇科植物总种数(包括变种)的75.29%。该区的蔷薇科植物从属、种层次上都表现出典型的温带性质,且以北温带性质为主;在属级、种级水平上,温带分布分别占该区蔷薇科植物总属数和总种数的95.45%、51.76%。该区蔷薇科植物属、种的特有现象不平衡,没有中国特有属,有中国特有种40种。 相似文献
993.
994.
N. Oud K. M. Marques J. G. F. Bronzwaer S. Brinckman C. P. Allaart C. C. de Cock Y. Appelman 《Netherlands heart journal》2010,18(9):402-407
Objectives. The aim of this study was to analyse the rate of major adverse clinical events in patients with coronary artery disease and a fractional flow reserve (FFR) of ≥0.75 and deferred for coronary intervention in daily practice. Methods. From 1 January to 31 December 2006, FFR measurement was initiated in 122 patients (5%) out of 2444 patients referred for coronary angiography. In two patients FFR measurement failed and in one patient the FFR value could no longer be traced in the documents. Thus, 119 patients (84 men, 64 years, range 41-85) were included in the evaluation (145 lesions). Major adverse clinical events (death, myocardial infarction, percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG)) and the presence of angina were evaluated at follow-up. Furthermore a cost-effectiveness analysis was performed. Results. In 93 patients (76%) the FFR value was ≥0.75. Seventy of these 93 patients (76%) were treated with medication alone or underwent PCI for a different lesion (medical treatment group). Average duration of follow-up of all 119 patients was 22 months (range 4 days to 30 months). In the medical treatment group seven patients (10%) experienced a major adverse clinical event related to the FFR-evaluated lesion during follow-up. In this study population, the use of FFR measurement is cost-reducing provided that at least 65% of the patients in the medical treatment group has had a PCI with stent implantation when the use of FFR measurement is impossible. In this case, the decision to use PCI with stent implantation is purely based on the angiogram. Conclusions. In patients with a coronary stenosis based on visual assessment and an FFR of ≥0.75 deferral of PCI or CABG is safe in daily clinical practice and saves money. (Neth Heart J 2010;18:402-7.) 相似文献
995.
The objective of this study was to assess the potential contribution of car-borne flora to species dispersal in a suburban area in Flanders (Belgium). Therefore, motor vehicle-borne flora was evaluated monthly for a random sample of 20 cars between October 1988 and September 1989. At the end of the experiment 33 car-borne plant species, with a total of 690 seedlings were identified from mud, attached to these vehicles. There was considerable temporal variation in the mud mass attached to the vehicles and therefore also the size and composition of the vehicle-borne flora varied during the year. Because mud retention on cars is a crucial factor in seed dispersal, the number of emerging seedlings is negatively correlated with precipitation in the week preceding the sampling. The flora dispersed by vehicles consists mostly of species with small, light seeds and a persistent seed bank. Usually, they are pioneer species of nitrogen-rich habitats. The nature of the vehicle dispersed flora was compared with the local flora of road verges and differed significantly from this in, e.g., seed length, seed weight, ecological groups, Ellenberg indicator values for nitrogen supply, potential dispersal strategies and rarity. A larger resemblance with the flora of the zone immediately adjacent to the carriageway was found. We only found a low similarity to other motor vehicle-borne floras. 相似文献
996.
Rios FS Moraes G Oba ET Fernandes MN Donatti L Kalinin AL Rantin FT 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2006,176(7):721-728
In some neotropical environments, fishes often experience periods of poor food supply, especially due to extreme fluctuations in rainfall regime. The fish species that experience periods of drought such as the traíra Hoplias malabaricus (Bloch 1794), may stand up to long-term food deprivation. In this study, experiments were performed in order to determine the dynamic of utilization of endogenous reserves in this species during starvation. Adult traíra were both fasted for 30–240 days and re-fed for 30 days following 90 and 240 days of fasting. Glycogen and perivisceral fat were primary energy substrates consumed. During the first 30 days, fish consumed hepatic and muscular glycogen, without exhausting these reserves, and used lipids from perivisceral fat. Hepatic lipids were an important energy source during the first 60 days of starvation and perivisceral fat were consumed gradually, being exhausted after 180 days. Protein mobilization was noticeable after 60 days of fasting, and became the major energy source as the lipid reserves were decreased (between 90 and 180 days). Following the longest periods of food deprivation, fish had utilized hepatic glycogen again. Fish re-fed for 30 days after 90 and 240 days of fasting were able to recover hepatic glycogen stores, but not the other energy reserves. 相似文献
997.
998.
桃红岭自然保护区梅花鹿对春季栖息地的利用 总被引:6,自引:0,他引:6
2005年3~5月在江西桃红岭自然保护区对华南梅花鹿(Cervus nippon kopschi)春季栖息地的利用进行了初步研究。选择10类生态因子,并设置256个10 m×10 m样方。选择指数的结果表明,梅花鹿喜欢灌丛和灌草丛、郁闭度较低、灌木盖度较小、食物丰富度高、半阴半阳及向阳、中坡位、坡度平缓、水源距离较近、人为干扰距离>800 m和海拔高度在300~450 m的环境。并对目前桃红岭梅花鹿栖息地存在的一些问题进行了初步分析。 相似文献
999.
卧龙自然保护区落叶松林不同恢复阶段地表甲虫的多样性 总被引:1,自引:0,他引:1
在四川卧龙国家自然保护区,以落叶松种植林邻近的天然落叶阔叶林(100年生,5块样地)为对照,分别选择刚种植(5年生)、幼年期(15年生)和成熟期(45年生)的3种落叶松林各4块样地,每个样地4个重复,研究森林不同恢复阶段地表甲虫的多样性。通过巴氏罐诱法取样,采集甲虫标本共7444号。步甲科、隐翅虫科和拟步甲科分别占总数的40·2%、38·3%和6·4%,共同构成本研究地区的优势类群。甲虫的科丰富度、多样性和均匀度在3种落叶松林内显著高于天然林,且在3种落叶松林中,刚种植的最高,幼年期的最低;个体数量正相反,天然林显著高于落叶松林,而且3种落叶松林内,幼年期最高,刚种植的最低。主坐标分析排序和聚类分析表明,不同树龄的落叶松林和天然阔叶林间的地表甲虫群落组成存在显著差异,成熟期落叶松林与幼年期落叶松林和天然阔叶林有较高的相似性。甲虫个体数量的季节变化在3种落叶松林内相似性很高,与天然阔叶林差异显著,而科丰富度、多样性和均匀度的季节变化在3种落叶松林以及天然阔叶林间相似性都很低。多元回归分析表明,林冠层、草本层及枯落物的高(厚)度和覆盖率是决定科丰富度、个体数量、多样性和均匀度的决定因素。以上结果表明,在科级水平上,地表甲虫群落组成在不同树龄的落叶松林以及天然落叶阔叶林内存在显著差异,虽然成熟期的落叶松林已经具有了部分天然阔叶林的甲虫群落特点,但仍无法完全恢复到天然林的群落水平。因此,在鼓励森林恢复的同时,保留大面积的天然落叶阔叶林免受破坏和干扰仍然是保护地表甲虫群落的必要措施。 相似文献
1000.
四川千佛山自然保护区的鸟类资源 总被引:6,自引:0,他引:6
通过2002年10月和2003年5月对保护区鸟类的集中调查,结合历史文献,确认保护区有鸟类13目35科160种.其中国家I级保护鸟类2种,Ⅱ级保护鸟类19种,完全或主要分布于我国的鸟类种类20种.保护区鸟类以留鸟和夏候鸟为主,有留鸟91种,夏候鸟48种,而冬候鸟、旅鸟分别只有13种和8种.鸟类区系组成为:古北界种类有30种,东洋界种类90种,广布种19种,以东洋界种类占优势,同时兼具西南区和华中区的特点.保护区鸟类主要分布在阔叶林和灌丛生境,其次是针阔混交林生境.保护区内鸟类水平分布的情况和垂直分布的情况都差异明显. 相似文献