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林窗的产生使森林环境发生了变化,进而影响森林生态系统的更新演替。本文选取东北地区具有典型性的次生林生态系统中人工小林窗(林窗直径与边缘木高之比小于0.5)为对象,对林窗内部及其附近林分的光量子通量密度(PPFD),距地面10cm的空气温度,土壤温度和土壤含水量(0-15cm,15-30cm)进行了观测。实验在林窗形成后的第二年进行,时间为2006年5-9月。结果表明:PPFD最高值出现在林窗北部边缘,尤其在生长季初期的五月份最为明显;晴天时PPFD到达最大值的时间较阴天提前;林窗北部的气温较高,南部的气温较低。土壤温度在林窗内变化剧烈,范围为1-8℃,最大值出现在林窗北部,且与气温最大值显著相关(R=0.735,P<0.05)。表层土壤水分高于下层土壤水分,但差异不显著(p>0.05);这主要是受林窗面积和地表植被的影响所致。上述结果表明,辽东山区次生林小林窗光量子最大值出现的位置与以往在北半球林窗观测结果基本一致,但出现最大值的时间在不同的纬度间存在着差异。空气温度和土壤温度的最大值也都出现在林窗北部,体现了光照对温度变化的影响。由于面积因素的影响,七月份温度变化与其它月份不同。土壤水分在雨季和旱季变化不大,这可能与林窗大小和所处地理位置有关。在本次观测的形状不规则小林窗中,小气候因子的变化对物种更新产生怎样的影响,需要开展进一步的研究。图5参44。
The appearance of gaps in the forest has changed the forest environment, thus affecting the succession of forest ecosystems. In this paper, the selection of the artificial small forest window (the ratio of the diameter of the forest window to the height of the edge wood is less than 0.5) in typical secondary forest ecosystems in northeastern China was taken as the object. The light quantum flux density (PPFD) Ground air temperature of 10cm, soil temperature and soil moisture (0-15cm, 15-30cm) were observed. The experiment was conducted in the second year after the formation of the gap and the time was from May to September in 2006. The results showed that the highest value of PPFD appeared on the northern edge of the forest gap, especially in the early May growth season. The highest PPFD reached the maximum in sunny days earlier than the cloudy day, the temperature in the northern forest was higher and the temperature in the south was lower . The soil temperature changed drastically in the gap, with the range of 1-8 ℃. The maximum appeared in the northern part of the gap and was significantly correlated with the maximum temperature (R = 0.735, P <0.05). The surface soil moisture is higher than the lower soil moisture, but the difference is not significant (p> 0.05); this is mainly due to the influence of the gill area and surface vegetation. The above results show that the location of the maximum QWL of the secondary forest in Liaodong mountainous area is basically the same as that observed in the past in the northern hemisphere, but the time of maximum appears different in different latitudes. The maximum air temperature and soil temperature also appeared in the northern part of the gap, reflecting the impact of light on temperature changes. Due to the effect of area, the temperature change in July is different from other months. Soil moisture did not change much in the rainy and dry seasons, which may be related to the size of the gap and geographical location. In this observation, the irregular shape of the Kobayashi window, the change of microclimate factors on the species renewal how the impact needs further study. Figure 5 Senate 44.