| Canopy structure is the main component part for the fruit tree, it has a closely-related with the solar energy intercepted, the rainfall intercepted and the forming of the microclimate ing the internal canopy. Study the dynamic changes and differents between differents ages and aspects not only has a great significance for understanding plant physiological processes and many other ecological processes, but also provide the basis for the scientific cultivation and construction for different ages and aspects. Using the new-style Canopy analysis instrument WinsCanopy-2005a to study the Configuration and Light Distribution Characteristics in Slope-Land Jujube Plantation of North Shaanxi from early May to late August, the results showed that:(1) All the targets had obvious dynamic changes in the growing season, to the end of jujube fruits mature in September, the leaf area index, chlorophyll content and leaf area have reached the maximum while the gap fraction,mean leaf angle and canopy photosynthesis photon flux density are minimized; the leaf angle scattered in 6~8°and most of the leaves had a smaller angle, nearly horizontal;the number of the leaves whose inclination below 20°played a decisive role on the accumulative leaf area. The total photosynthetic photon flux density above and below canopy has a significant diurnal and seasonal changes and the changes of the upper and lower canopy are consistent.(2) The canopys has a big differents between ages,to the flowering stage, 10-year trees has the highest leaf area index, leaf area and chlorophyll content while the gapfraction and photosynthetic photon flux density under the canopy are smallest, the canopy light interception and fruit growth are strongest; 3-year trees has the smallest leaf area index, leaf area and chlorophyll content while the gapfraction and photosynthetic photon flux density under the canopy are highest, the canopy light interception and fruit growth are weakest.(3) The branch crown volume, crown width and yield are quite differents between ages, generally speaking, 10-year trees has the largest branch left amount,tree high, crown width and output and the fruit quality is highest, the main branch volume and secondary branch growth was significantly greater than others, it has the most canopy fruit production capacity and light energy utilization efficiency, the amount of branch volume and secondary branches had a bigger impact on the canopy light interception capacity.(4) The canopys has a big differents between aspects, to the flowering stage, the dark aspect trees has the smallest leaf area index and chlorophyll content while the gapfraction and photosynthetic photon flux density under the canopy are highest, the sun aspect trees has the highest leaf area index and chlorophyll content while the gapfraction and photosynthetic photon flux density under the canopy are smallest, sun aspect adequate light strongly and its branch growth shoot, the canopy light interception capabilities and fruit productive.is finist.(5) The branch crown volume, crown width and yield are quite differents between aspects, generally speaking,sun aspect trees has the largest branch left amount,tree high, crown width and output and the fruit quality is highest.Jujube are hi light plants, adequate lighting is conducive to the accumulation of dry matter, fruit enlargement and the synthesis of sugar, its also good for fruit development and a high output.(6) Gapfraction, openness, leaf area index, photosynthetic photon flux density of the upper and lower cannopy has a good correlation and the correlation coefficients reached 0.80 or more; The gapfraction,openness and leaf area index had a great influence on the canopy light interception capability, and the other indicators suah as the mean leaf angle,site factors and photosynthetic active radiation had no significant correlation, they are not affected the canopy light interception ability; Direct radiation is the main radiation below the canopy.
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