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1.
为了阐明立体种养对蔗田生态和甘蔗品质的影响,以传统的甘蔗栽培模式(CK)为对照,对“甘蔗间种大豆,畦间沟养鱼”的立体种养模式(T)进行了研究。结果表明:(1)T模式的株间总体相对光强要较CK大,但是T行间各层的总体相对光强要小于CK:(2)T模式的甘蔗地上部分的温度和相对湿度要高于CK模式,而且温差在后期也大:(3)T模式后蔗田土壤营养的平衡性和稳定性要比CK模式好;(4)T模式比CK模式更有利于干物质和甘蔗品质的形成:(5)蔗田生态因子与甘蔗茎的单株干物质及田间锤度的相关分析显示T模式受自然气象因子的影响要较CK稍小。因此.T模式值得在人多地少且有精耕细作传统的蔗区推广。 相似文献
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鸡腿蘑菌丝体的同工酶研究 总被引:7,自引:1,他引:7
用8种不同培养基配方,培养鸡腿蘑菌丝体,其同工酶分析结果表明,鸡腿蘑菌丝体酯酶(EST)同工酶谱差异明显,过氧化物酶(POD)同工酶谱差异明显。 相似文献
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L. G. G. Warne 《The Journal of Horticultural Science and Biotechnology》2013,88(4):285-295
Three varieties of plum were inoculated with the three viruses, plum line pattern (apple mosaic), prune dwarf and plum bark split, either singly or in combinations of line pattern with each of the others. Bark lesions developed more rapidly on Cambridge Gage trees infected with bark split virus alone than on those infected also with line pattern virus. Symptoms characteristic of line pattern virus on trees of Cambridge Gage, Early Laxton and Italian Prune were not affected by infection with the bark split virus, but were suppressed by the prune dwarf isolate. This suppression was apparently due to the presence of a mild strain of line pattern virus contaminating the prune dwarf inoculum.The occurrence of antagonistic strains of line pattern virus, differing in virulence, precludes any precise definition of diagnostic symptoms. 相似文献
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Use and misuse of landscape indices 总被引:13,自引:3,他引:13
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Giovanni Zurlini Kurt H. Riitters Nicola Zaccarelli Irene Petrosillo 《Landscape Ecology》2007,22(5):705-721
We describe a framework to characterize and interpret the spatial patterns of disturbances at multiple scales in socio-ecological
systems. Domains of scale are defined in pattern metric space and mapped in geographic space, which can help to understand
how anthropogenic disturbances might impact biodiversity through habitat modification. The approach identifies typical disturbance
'profiles' based on the similarity of trajectories in a pattern metric space over a range of spatial scales. When different
profiles are coherent in pattern metric space, they describe a regional spatial pattern. The divergence of a profile indicates
a scale-dependent transition to a local spatial pattern, which can be examined for correspondence to different regions of
geographic space. We illustrate the conceptual model with simulated maps and real disturbance maps from satellite imagery
in south Italy. The results suggest that management of disturbances in the study region depend less on local drivers of disturbance
and more on broader-scale drivers within the socio-ecological framework. 相似文献
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Amy C. Burnicki 《Landscape Ecology》2012,27(5):713-729
Researchers have emphasized the value of linking observed patterns of land-cover change to the processes driving changes in
land-use to explain the dynamics of a land change system. The association of pattern and process requires an accurate quantification
of the spatial characteristics of land-cover change. The objective of this research is to assess the impact of error on the
accuracy of landscape pattern analyses performed on maps of change. Simulation was used to develop of a series of error-free
and error-perturbed change maps, which varied with respect to the pattern of change occurring between the time-1 and time-2
land-cover maps and the patterns of error associated with the time-1 and time-2 land-cover maps. A variety of change and error
patterns were examined. The error-free and error-perturbed change maps were compared by calculating landscape pattern metrics,
which revealed the degree to which error altered the pattern of change. The introduction of error notably changed the structure
of the persistent and transitioning classes, with metrics indicating a more fragmented and variable landscape under error.
Agreement between the error-free and error-perturbed maps improved when a greater amount of change occurred within the time-series,
change was concentrated at the boundaries of land-cover classes and when time-2 errors were increasingly correlated to their
time-1 counterparts. These results have several implications for change pattern analyses given the fundamental nature of land-cover
change. 相似文献
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A Bayesian test of hierarchy theory: scaling up variability in plant cover from field to remotely sensed data 总被引:4,自引:0,他引:4
Hierarchy theory predicts that a hierarchy of process rates should be reflected in a hierarchy of spatial and temporal scales observable on the landscape. We will show that multiple scales of pattern for total plant cover measured in the field at 1-m resolution are correlated with scales of vegetative pattern obtained from remotely sensed data with resolutions of 25 m2 and 30 2. Second, using four models based on postulates of hierarchy theory, we will combine the scales of pattern of each individual species within a community to estimate the remotely sensed community scales of pattern. Finally, we will compare the four models using a Bayesian analysis to determine which model best portrays how vegetative patterns of individual species combine to produce remotely observed community patterns. The results of the model comparisons provide an example of how postulates of hierarchy theory can be tested and how individual species patterns can be scaled-up to estimate remotely observed scales of pattern. 相似文献
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应用聚集度指标法、Iwao回归分析法、Taylor幂指数法对怀柔区试验地板栗林内栗瘿蜂虫瘿空间分布格局进行了分析.结果表明:栗瘿蜂虫瘿在板栗林内呈现出聚集分布的特点,而且种群在一切密度下都是聚集的,聚集强度随种群密度的升高而增加.栗瘿蜂虫瘿数量在树冠东、西、南、北4个方向上的分布差异显著,以南方向最多,北方向最少.树冠上、中、下层虫瘿分布存在显著差异,以下层分布最多,上层最少.采用Iwao的方法分析了不同方位、不同层次分布特点和空间分布形式.结果表明:各个方向、不同层次上虫瘿分布普遍呈现聚集分布的特点.根据Iwao提出的新序贯抽样理论,列出了试验地区的序贯抽样表,为林间抽样调查和防治提供了依据. 相似文献
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通过田间调查和计算,明确了铜绿丽金龟幼虫在越橘园内呈聚集分布,且符合奈曼分布型和负二项分布型.通过对比三点法、五点法和棋盘式抽样法发现,棋盘式抽样法最适合对铜绿丽金龟幼虫进行调查.在棋盘式抽样法中,以每个样点的抽样面积为1 m2为最佳,这样既省时省力,又高效. 相似文献
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Landscape pattern indices are common tools of landscape ecologists, affording comparisons of different study areas, or the
same study area at different times. Since the advent of popular index-calculating software, more landscapes can be analyzed
in short amounts of time, yet the behaviour of landscape pattern indices can vary for different contexts or data characteristics,
complicating interpretation. I applied a selected set of landscape pattern indices to fine-resolution (3 m) data representing
a highly fragmented landscape – Corn Belt Iowa agriculture – to investigate the performance of landscape pattern indices.
Indices measured pattern attributes that affect the viability of small mammal populations, namely habitat proportion and connectivity
and landscape grain size and heterogeneity. Results showed that the performance of indices for fine-resolution data can be
highly variable, depending upon data and contextual issues like the presence of linear elements and the amount of habitat.
For these Corn Belt landscapes good habitat proportions and patch sizes were small (commonly less than 10% and less than 1 ha,
respectively), and connectivity was variable depending on the measure. Aggregation and mean nearest neighbour indices performed
better than other connectivity indices. Fine-resolution data representing highly fragmented landscapes can raise difficulties
for indices of landscape configuration. Landscape pattern indices require improvement to perform better for increasingly available
fine-resolution data representing common landscape types. 相似文献
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Indices of landscape pattern 总被引:170,自引:1,他引:170
R. V. O'Neill J. R. Krummel R. H. Gardner G. Sugihara B. Jackson D. L. DeAngelis B. T. Milne M. G. Turner B. Zygmunt S. W. Christensen V. H. Dale R. L. Graham 《Landscape Ecology》1988,1(3):153-162
Landscape ecology deals with the patterning of ecosystems in space. Methods are needed to quantify aspects of spatial pattern that can be correlated with ecological processes. The present paper develops three indices of pattern derived from information theory and fractal geometry. Using digitized maps, the indices are calculated for 94 quadrangles covering most of the eastern United States. The indices are shown to be reasonably independent of each other and to capture major features of landscape pattern. One of the indices, the fractal dimension, is shown to be correlated with the degree of human manipulation of the landscape. 相似文献
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Multiple landscape scales: An intersite comparison 总被引:10,自引:0,他引:10
R. V. O'Neill S. J. Turner V. I. Cullinan D. P. Coffin T. Cook W. Conley J. Brunt J. M. Thomas M. R. Conley J. Gosz 《Landscape Ecology》1991,5(3):137-144
Vegetation transect data from three locations were analyzed to determine if multiple scales of pattern could be detected. The sites included a semiarid grassland in New Mexico, a series of calcareous openings in a deciduous forest in Tennessee, and a shrub-steppe system in Washington. The data were explored with four statistical techniques. A scale of pattern was accepted if detected by more than one analytical method or located by a single method in multiple taxa. The analyses indicated 3–5 scales of pattern on all three sites, as predicted by Hierarchy Theory. 相似文献
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由山体、河流、湖泊所形成的自然山水格局,作为城市绿地的组成部分,是城市绿地网络体系中不可或缺的一分子.简介四川省自贡市自然山水格局及其基本特征.提出在自贡市中心城区绿地系统规划中应归纳形成“一心都市聚茵、两带十字绿轴、三环绿屏交错、四楔绿廊穿插、多园星罗棋布”平面与垂直相结合的立体化绿地系统布局结构.分析自然山水格局对自贡城市绿地系统(城市景观特色,城市生态安全,构建城市绿色开敞空间)的影响.建议在今后的工作中针对不同地形地貌特征进行更加深入的探索研究和实践,以便可以为丘陵山地构建可持续发展的宜居城市提供更多的参考. 相似文献