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1.
秦岭北坡栓皮栎种群动态的研究   总被引:12,自引:1,他引:11  
对秦岭北坡栓皮栎种群动态进行了系统研究,分析了种群的年龄结构和分布格局。编制了静态生命表。绘制了存活曲线.结果表明,秦岭北坡栓皮栎种群年龄结构属于进展型,幼龄个体多。中老龄个体少;种群在I、Ⅱ龄级时死亡率最高.随着年龄增加,死亡率逐渐降低;到Ⅶ、Ⅷ龄级。由于生理衰老。死亡率回升;栓皮栎种群存活曲线属于DeeveyⅢ型;种群分布格局总体上的呈聚集型。随年龄增加,种群聚集强度降低。在高海拔地区,种群趋向随机分布.海拔800~1100m是栓皮栎种群较为适宜的生境.对于低海拔地区栓皮栎林要加强保护,减少人为干扰;中海拔地区应加强抚育管理和适时间伐,高海拔地区应加强目的树种的抚育.  相似文献   

2.
陕西不同林区栓皮栎种群空间分布格局及动态的比较研究   总被引:33,自引:1,他引:32  
在陕西黄龙山区、秦岭北坡和巴山北坡设置 1 0× 1 0 m2 样方 98个 ,应用相邻格子法进行每木调查获得野外资料 ,采用离散分布理论拟合检验、t检验和聚集强度测定的方法 ,对栓皮栎种群空间分布格局及动态进行了对比研究。结果表明 :1栓皮栎种群在黄龙山区为奈曼 A型分布 ,秦岭北坡和巴山北坡为负二项分布 ;聚集强度 ,秦岭北坡 >黄龙山区 >巴山北坡。 2在秦岭和巴山北坡中低海拔地区 ,种群为负二项分布 ,随海拔升高 ,秦岭北坡趋向随机分布 ,巴山北坡趋向均匀分布 ;两地种群聚集强度随海拔升高呈“低 -高 -低”的变化格局。3秦岭北坡 1~ 1 0年生种群的聚集度最大 ,随着年龄增加 ,聚集强度逐渐下降 ;而黄龙山区和巴山北坡种群的聚集强度随年龄增加而增强。栓皮栎种群生物学和生态学特性与环境因素共同作用是种群分布格局形成的主要因素 ,人为干扰对分布格局具有重要影响。根据环境条件和种群动态规律实行不同的经营方式是实现栓皮栎林持续利用的根本性措施  相似文献   

3.
北京山区栓皮栎林优势种群点格局分析   总被引:15,自引:8,他引:7  
樊登星  余新晓 《生态学报》2016,36(2):318-325
采用点格局分析方法对北京山区栓皮栎林主要种群和不同发育阶段种群的空间分布格局及相互关系进行分析。结果表明:(1)群落物种组成简单,栓皮栎和油松是群落的优势种群,优势种群以中径木为主,缺乏可供更新的幼苗,种群呈现出衰退趋势;(2)在研究尺度内,栓皮栎、油松单种的空间分布格局以聚集型分布为主,随着尺度的增大呈现出随机分布和均匀分布的趋势;栓皮栎和油松呈现显著负相关;(3)优势种群不同发育阶段的空间分布格局与研究尺度紧密相关,栓皮栎小树和中树以聚集型分布为主、大树呈随机分布,而油松不同发育阶段均以随机分布为主;(4)栓皮栎、油松种群不同发育阶段之间的空间关联主要发生在小尺度范围内,小树和中树以正关联为主,而中树和大树、小树和大树以负关联为主;随着研究尺度的增大趋于无关联。  相似文献   

4.
陕西不同地区栓皮栎种群年龄结构动态模型的研究   总被引:7,自引:1,他引:6  
栓皮栎种群动态模型能阐明其自然种群动态的规律,揭示种群的内在机制和对种群行为进行预测。矩阵模型是一种i状态分布方法,依靠矩阵形式来处理种群的特征分布,可以模拟和预测种群中各个年龄组的数量动态和年龄结构的变化,它能够从目前已知的年龄结构及种群的生存率和生育率,来推测种群的未来年龄结构。在研究栓皮栎种群动态时,也借用该模型对栓皮栎种群各年龄组的结构和数量动态作出预测。Leslie矩阵模型就是该模型中的一种,利用该模型的理论和方法,对栓皮栎种群的自然变化过程进行了模拟和预测。结果发现,从分布中心到分布边缘,随着生境的差异,栓皮栎种群产生幼苗的年龄级、内禀增长率、生育力和幼苗的数量都发生变化,预测结果与实际反映的情况基本一致,表明Leslie矩阵模型是一种较为理想的反映种群动态的模型。模型表达形式简单,参数生态学意义确切,应用精度高,从而达到准确预测栓皮栎种群动态的目的。  相似文献   

5.
宝天曼落叶阔叶林样地栓皮栎种群空间格局   总被引:1,自引:0,他引:1  
种群空间格局分析有利于更好地理解格局形成的潜在生态过程.本研究在温带-亚热带过渡区的宝天曼自然保护区内选择两个1 ha固定监测样地,以栓皮栎(Quercus variabilis)为研究对象,采用单变量和双变量g(r)函数分析了两个典型样地中栓皮栎种群空间分布格局、4个不同生长阶段的空间分布格局和空间关联性,以及栓皮栎活立木与残干间的空间关联性.结果表明:(1)栓皮栎种群分布格局以聚集为主,样地Ⅰ的聚集性更强,而样地Ⅱ则表现出较大的随机性;(2)在两个样地中,早期阶段的个体均表现为聚集分布格局,而后期阶段的个体则表现为随机分布格局;(3)样地Ⅰ中栓皮栎种群不同生长阶段均表现为空间正相关,样地Ⅱ中栓皮栎种群的早期阶段与其后的两个阶段间均表现为空间负相关;(4)样地Ⅰ中栓皮栎活立木与残干之间为空间正相互作用,样地Ⅱ中栓皮栎活立木与残干之间无空间关联性.宝天曼自然保护区栓皮栎种群空间分布格局可能受环境异质性的作用,并对自身的天然更新产生影响.  相似文献   

6.
【目的】厘清天然广布树种栓皮栎叶片解剖结构的种群变异及其与环境因子的关系。【方法】以中国28个天然分布栓皮栎种群叶片为研究对象,用常规石蜡切片结合光学显微技术对栓皮栎叶片解剖性状进行研究,用巢式方差分析、Pearson相关性分析等方法对栓皮栎叶片解剖结构的种群变异与环境因子关系进行分析。【结果】(1)栓皮栎叶片解剖性状在28个种群间存在显著差异,平均变异系数为7.84%~15.16%,且同一叶片解剖性状在不同种群间的变异范围不同;(2)9个解剖性状在种群内及种群间均存在极显著差异,平均表型分化系数为37.44%,解剖性状变异主要来自种群内;(3)叶片厚度、上表皮厚度、栅栏组织厚度、海绵组织厚度与纬度呈显著正相关关系,年均气温及年降水量对上表皮厚度和栅栏组织厚度有显著影响。【结论】栓皮栎具有丰富的遗传多样性,为适应低温与干旱,栓皮栎叶片整体呈增厚趋势。研究结果为了解栓皮栎环境适应策略提供理论依据。  相似文献   

7.
不同地区不同尺度下栓皮栎种群的空间分布格局   总被引:8,自引:0,他引:8  
种群的分布格局与空间尺度有密切的关系.本研究将传统方法与点格局分析法结合起来,探讨了不同地区不同尺度下栓皮栎种群的空间分布.结果显示:随着样方面积的增大,种群的聚集度都有逐渐增大的趋势,当样方面积为10 0、2 0 0 m2 时,部分地区的丛生指标It、Cassie指数CA 小于零,当样方面积大于或等于4 0 0 m2 时,丛生指标It>0、Cassie指数CA>0、平均拥挤度m* >>1、L loyd聚块性指标和Morisita指数Iδ>1.用Morisita指数的随机分布偏离度的显著性F分布检验,当样方面积达到4 0 0 m2时,栓皮栎种群表现为聚集分布.同时,对不同地区不同样方面积上的栓皮栎种群进行Taylor和Iwao模型回归,Taylor回归系数b的变化从样方10 0、2 0 0 m2的b<1到4 0 0 m2的b>1,Iwao模型参数α、β值都表现为α>0 ,β>1,说明其分布格局主要表现为聚集分布.当样方面积为6 0 0、80 0 m2时,栓皮栎种群的空间格局呈现出随机分布.  相似文献   

8.
海南岛黎母山四眼斑水龟种群密度与空间分布格局   总被引:2,自引:1,他引:1  
2004年3~7月,采用系统抽样法在海南岛黎母山对四眼斑水龟(Sacalia quadriocellata)种群密度与空间分布进行了调查,采用Cassie指数、David&Moore指数、Morisita指数和Lloyd指数测定了四眼斑水龟种群空间分布格局。结果表明,(1)四眼斑水龟种群分布于海拔170~470m范围内,在垂直梯度上呈现不连续的分布状态;(2)在海拔170~470m范围内种群相对密度为0.011~0.050只/笼捕日;(3)种群空间分布呈现聚集分布格局;(4)资源的空间分布特点和人为干扰可能对四眼斑水龟种群密度及空间分布格局有重要影响。  相似文献   

9.
秦岭北坡不同生境栓皮栎实生苗生长及其影响因素   总被引:1,自引:0,他引:1  
马莉薇  张文辉  薛瑶芹  马闯  周建云 《生态学报》2010,30(23):6512-6520
栓皮栎(Quercus variabilis)是中国暖温带和亚热带林区的主要建群种,也是重要的栲胶、软木资源树种。为了阐明栓皮栎在不同生境条件下的种子成苗、实生苗生长及其与环境因素的关系,采用典型样地调查的方法,对秦岭北坡栓皮栎林3种生境中(林窗、林缘、林下)的栓皮栎种子库中种子数量、实生苗的存活数量、生长情况及生物量分配进行了研究,对影响实生苗生长发育的环境因素进行了相关分析。结果表明:林下、林窗和林缘的种子库中种子数量差异显著(P0.05),3种生境中能够萌发形成1a苗的种子数量少,种子能否萌发明显受枯枝落叶层厚度、光照强度和空气湿度的影响;栓皮栎种群有充足的苗库,其中较大年龄实生苗数量是种群能否持续更新的关键,林下、林窗和林缘中8a苗分别占该年龄实生苗总量的22.53%、45.60%和31.87%,林窗中较大年龄实生苗的数量比林下和林缘多,林窗为栓皮栎实生苗的定居提供了有利条件;栓皮栎实生苗的生长与光照强度和空气温度显著正相关,与土壤含水量显著负相关,林窗中实生苗的生长状况和生物量积累均优于林缘、林下。林窗对栓皮栎种群更新有利。在今后的栓皮栎林的经营过程中,可以适当间伐,增加林窗数量,为种群可持续发育提供有利条件。  相似文献   

10.
利用径级法和方差/均值法对我国不同地理区域上栓皮栎种群年龄结构及其空间分布格局进行分析.结果表明: 在水平梯度上,中部、北部、南部和西部栓皮栎种群均呈倒J型分布,而东部种群呈衰退型分布.成年树在中部和南部均呈集群分布,而北部区域呈现随机分布;幼树在在北、中和西部区域均为集群分布,而在南部和东部均呈随机分布.在纬向梯度上,幼树聚集强度的纬向趋势为中>北>南,而成年树聚集强度为中>南>北,经向梯度上幼树和成年树的聚集强度均为中>西>东.在垂直梯度上,中、低海拔种群呈倒J型分布,高海拔呈现衰退型.幼树在不同海拔均呈集群分布;成年树在低海拔为随机分布,而在高海拔和中海拔均为集群分布.幼树和成年树的聚集强度均为中海拔>高海拔和低海拔.在不同地理区域上,幼树的聚集强度均高于成年树.因此,栓皮栋种群结构及其分布格局主要是由环境梯度变化及其自身生物学特性决定,证实了“中心-边缘”种群假说.  相似文献   

11.
New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn2NPSCH2CH2Sa(P-Sa) (Bn = benzyl, 4), Bn2NPSCHCHSa(CH2)3CaH2(P-Sa)(Ca-Sa) (6) and Bn2NP(4-XC6H4OMe)2 (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)2] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl2Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the νCO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The 1JPRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the 1JPSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh3. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh3.  相似文献   

12.
Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.  相似文献   

13.
The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.  相似文献   

14.
15.
《环境昆虫学报》2014,(5):790-804
综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生(宾主共栖和异种共栖)、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌(原生动物、细菌、真菌和放线菌)和外生菌(蚁巢伞菌等)间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用(如纤维素酶)及今后研究物种间的协同进化提供了基础资料。  相似文献   

16.
To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.  相似文献   

17.
18.
In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.  相似文献   

19.
The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE2, PGD2, PGF, TXB2 and 6-keto-PGF. In all types studied PGE2 and TXB2 were the major products formed. The identification of PGE2 and TXB2 was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.  相似文献   

20.
A new series of antibacterial and antifungal triazine-derived mono- and di-substituted (symmetrical and unsymmetrical) Schiff-bases and their cobalt(II), copper(II), nickel(II) and zinc(II) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments and IR and electronic spectral measurements. IR spectra indicated the ligands to act as tridentate towards divalent metal ions via a trazine-N, the azomethine-N and, indole-NH and deprotonated-O of salicylaldehyde. The magnetic moments and electronic spectral data suggest octahedral geometry for the Co(II), Ni(II) and Zn(II)complexes and square-pyramid for Cu(II) complexes. NMR spectral data of the ligands and their diamagnetic zinc(II) complexes well-define their proposed structures/geometries. Elemental analyses data of the ligands and metal complexes agree with their proposed structures/geometries. The synthesized ligands, along with their metal complexes were screened for their antibacterial activity against Escherichia coli, Bacillus subtillis, Shigella flexneri, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata. The results of these studies show the metal complexes to be more antibacterial/antifungal against two or more species as compared to the uncomplexed Schiff-base ligands.  相似文献   

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