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闽北闽粤栲天然林林隙物种数量特征及更新规律分析

2017-10-12郑德祥蔡杨新许鲁东范胜煌吴联杯施晓春钟兆全黄梅珍

植物资源与环境学报 2017年3期

郑德祥, 蔡杨新, 许鲁东, 范胜煌, 吴联杯, 施晓春, 钟兆全, 黄梅珍

(1. 福建农林大学林学院, 福建 福州 350002; 2. 福建省顺昌县国有林场, 福建 顺昌 353200)

闽北闽粤栲天然林林隙物种数量特征及更新规律分析

郑德祥1,①, 蔡杨新1, 许鲁东1, 范胜煌1, 吴联杯1, 施晓春1, 钟兆全2, 黄梅珍1

(1. 福建农林大学林学院, 福建 福州 350002; 2. 福建省顺昌县国有林场, 福建 顺昌 353200)

以福建省顺昌县的闽粤栲〔Castanopsisfissa(Champ. ex Benth.) Rehd. et Wils.〕天然林为研究对象,根据林隙面积(A)划定4个等级(A<50 m2、50 m2≤A<100 m2、100 m2≤A<150 m2和150 m2≤A<200 m2)的样地,并以非林隙样地为对照,对林隙和非林隙的乔木层、灌木层和灌草层中的物种分布、组成及生长状况进行调查和统计;在此基础上,对林隙和非林隙中主要物种的数量特征和更新响应规律进行比较分析。结果表明:闽粤栲天然林林隙和非林隙的乔木层分别有54和35种植物,共有种28种;灌木层分别有61和37种植物,共有种29种;灌草层分别有72和49种植物,共有种37种。从乔木层和灌木层各种类的重要值及灌草层各种类的密度看,林隙和非林隙中的优势种类均为闽粤栲和木荷(SchimasuperbaGardn. et Champ.)等,且林隙和非林隙间各优势种类的重要值差异不明显,其中,闽粤栲的重要值和密度均位居第一。从林隙和非林隙间各优势种类的重要值差值看,林隙的主要优势种类(如闽粤栲和木荷等)对林隙更新响应不明显,而其他种类对林隙则有强烈或中等的正、负更新响应,且在不同林层间有差异。从平均更新密度看,林隙面积对各优势树种的更新有一定影响,其中,林隙面积在150~200 m2时闽粤栲和丝栗栲(CastanopsisfargesiiFranch.)的平均更新密度最大,林隙面积在100~150 m2时米槠〔Castanopsiscarlesii(Hemsl.) Hay.〕、木荷、青冈〔Cyclobalanopsisglauca(Thunb.) Oerst.〕和黄毛润楠(MachiluschrysotrichaH. W. Li)的平均更新密度最大,但在不同面积林隙间各树种的平均更新密度无显著差异(P=0.867)。研究结果说明:在闽粤栲天然林中,对林隙更新响应不明显的种类较易成为林分的优势种或建群种,但林隙面积对树种的更新密度没有明显影响;从林隙到林冠的发育过程中,闽粤栲始终处于该林分的优势地位。

闽粤栲天然林; 林隙; 优势树种; 重要值; 密度; 更新规律

Abstract: Taking natural forest ofCastanopsisfissa(Champ. ex Benth.) Rehd. et Wils. in Shunchang County of Fujian Province as research object, and taking non-gap plot as control, according to gap area (A), four grades (A<50 m2, 50 m2≤A<100 m2, 100 m2≤A<150 m2and 150 m2≤A<200 m2) of plots were delimited. Distribution, composition and growth status of species in arbor layer, shrub layer and shrub-herb layer of gap and non-gap were investigated and counted. On this basis, the quantitative characteristics and regeneration response regularity of main species in gap and non-gap were compared and analyzed. The results show that arbor layers of gap and non-gap in natural forest ofC.fissahave 54 and 35 species, respectively, common species is 28; shrub layers have 61 and 37 species, respectively, common species is 29; shrub-herb layers have 72 and 49 species, respectively, common species is 37. From important values of species in arbor layer and shrub layer, and density of species in shrub-herb layer, dominant species areC.fissaandSchimasuperbaGardn. et Champ., etc. in gap and non-gap. And differences in important value of dominant species in gap and non-gap are not obvious, in which, the important value and density ofC.fissaare ranked first. From difference value of important value of dominant species in gap and non-gap, main dominant species (such asC.fissaandS.superba, etc.) in gap have unobvious regeneration response to gap, but other species have strong or moderate positive and negative regeneration responses to gap, and there are differences in different forest layers. From average regeneration density, gap area has a certain influence on regeneration of dominant tree species, in which, average regeneration densities ofC.fissaandCastanopsisfargesiiFranch. are the biggest with gap area of 150-200 m2, while those ofCastanopsiscarlesii(Hemsl.) Hay.,S.superba,Cyclobalanopsisglauca(Thunb.) Oerst. andMachiluschrysotrichaH. W. Li are the biggest with gap area of 100-150 m2. However, there is no significant difference (P=0.867) in average regeneration density among tree species in gaps with different areas. It is suggested that in natural forest ofC.fissa, species with unobvious regeneration response to gap are easily becoming main dominant species or constructive species, but gap area has no obvious effect on regeneration density of tree species. During the development process from gap to canopy,C.fissais always in the dominant position in the forest.

Keywords: natural forest ofCastanopsisfissa(Champ. ex Benth.) Rehd. et Wils.; gap; dominant tree species; important value; density; regeneration regularity

森林更新受多种因子的影响,与人为干扰、郁闭度、枯落物盖度及林龄等因子均有一定的关系[1-2]。林隙(gap)是森林更新过程中的一个重要阶段,可促进森林生态系统的更新,并能维持生态系统群落的稳定性[3]。林隙的形成改变了林隙内的生态环境,使其不同于周围林冠下的生态环境;树种的差异导致对林隙的占据和利用情况各有不同,因而使林隙内外树种的更新格局发生变化[4];林隙作为幼苗存活和更新的有效场所,具有保存森林物种多样性和推动森林更新的重要作用[5],其中,混交林林隙较纯林林隙更有利于林分更新和树木生长[6]。目前,林隙动态研究已成为森林生态学研究的热点之一,国内外学者已进行了一系列研究[7-13]。

闽粤栲〔Castanopsisfissa(Champ. ex Benth.) Rehd. et Wils.〕又名黧蒴锥,是福建省天然阔叶林的主要树种之一,由于其成材时常存在腐朽空心现象,导致该树种的利用价值不高而被作为杂木清除或其林分被人为改造,使闽粤栲的自然资源日益缩减。……

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