落葉松人工林冠下光環(huán)境對(duì)更新幼樹生長(zhǎng)的影響1)

歷胤男 劉盛 李國(guó)偉 劉慶忠

(北華大學(xué)，吉林，132013)

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落葉松人工林冠下光環(huán)境對(duì)更新幼樹生長(zhǎng)的影響1)

歷胤男 劉盛 李國(guó)偉 劉慶忠

(北華大學(xué)，吉林，132013)

采用冠層分析系統(tǒng)對(duì)落葉松人工林冠下人工更新落葉松幼樹的光環(huán)境進(jìn)行了調(diào)查。依據(jù)調(diào)查數(shù)據(jù)分析了直射光指數(shù)、散射光指數(shù)、綜合光指數(shù)與幼樹死亡率、樹高生長(zhǎng)量和地徑生長(zhǎng)量的關(guān)系，結(jié)果表明：所選3個(gè)光照指數(shù)大小對(duì)落葉松幼樹死亡率、樹高和地徑生長(zhǎng)量均有顯著影響，冠下落葉松幼樹死亡率隨光照指數(shù)的增大而減小，樹高和地徑生長(zhǎng)量隨光照指數(shù)的增大而增大。光照指數(shù)在小于0.25時(shí)，死亡率最高，樹高和地徑生長(zhǎng)量處于最低水平；當(dāng)直射光指數(shù)和綜合光指數(shù)在0.25～0.45時(shí)，是落葉松幼樹在林下維持生存的基本光照平衡區(qū)間；在大于0.45時(shí)，幼樹的保存率和生長(zhǎng)表現(xiàn)出了旺盛的狀態(tài)，說明落葉松在林冠下更新造林的直射光指數(shù)和綜合光指數(shù)不應(yīng)小于0.45。3個(gè)光照指數(shù)之間沒有顯著的好壞差別，呈現(xiàn)了相同的規(guī)律性。只是對(duì)于幼樹死亡率的影響，散射光指數(shù)不如直射光指數(shù)敏感，同時(shí)也說明直射光對(duì)于幼樹的生存具有更重要的意義。

落葉松人工林；冠下更新；光照指數(shù)；死亡率；生長(zhǎng)量

Using canopy analysis system (HemiView) under canopy of artificial regeneration artificial larch, we investigated the sapling light environment. According to the survey data we analyzed the direct light index (DSF), light scattering index (ISF), integrated optical index (GSF) and sapling mortality, tree height growth quantity and diameter growth. The three selected light index sizes of larch sapling mortality, tree height and diameter growth were significantly affected. Under the canopy of larch, the sapling mortality was decreased with the increase of light index, the growth of tree height and ground diameter was increased with the increase of the index of light. Under the light index of less than 0.25, there was the highest mortality, tree and lowest height and diameter growth. When the direct light index and comprehensive index were in 0.25-0.45, the light was in forest survive basic lighting balance interval for larch sapling. When light index was greater than 0.45, the survival rate and growth of young trees showed a strong state, indicating that larch under the canopy of reforestation direct light index and comprehensive index should not be less than 0.45. For stand and fall, there was no significant difference between three light indexes with the same regularity. For the mortality rate of young trees, the sensitive effect of ISF was less than DSF, indicating that direct light was important in the survival of the young trees.

中國(guó)人工林面積已居世界首位[1]，占全國(guó)森林面積的20%；在我國(guó)東北林區(qū)，落葉松(Larixolgensis)是人工更新的主要樹種[2]，到目前為止，在所有人工造林樹種中的保有面積是最大的。長(zhǎng)期的人工林經(jīng)營(yíng)使人們發(fā)現(xiàn)，大面積的人工純林存在很多弊端[3]，如群落結(jié)構(gòu)簡(jiǎn)單、缺乏生物多樣性、林地退化、病蟲害嚴(yán)重等[4]。……