白　超，趙中華，胡艷波

(中國(guó)林業(yè)科學(xué)研究院 林業(yè)研究所，國(guó)家林業(yè)局林木培育重點(diǎn)實(shí)驗(yàn)室，北京 100091)

?

基于交角的林木競(jìng)爭(zhēng)指數(shù)應(yīng)用研究

白超，趙中華，胡艷波

(中國(guó)林業(yè)科學(xué)研究院 林業(yè)研究所，國(guó)家林業(yè)局林木培育重點(diǎn)實(shí)驗(yàn)室，北京 100091)

[摘要]【目的】 基于交角的林木競(jìng)爭(zhēng)指數(shù)(CI)簡(jiǎn)潔，能同時(shí)表達(dá)出競(jìng)爭(zhēng)木上方的遮蓋和側(cè)翼的擠壓。探討不同林分用胸徑(D)或通過(guò)胸徑-樹高(D-H)曲線預(yù)估樹高后替代實(shí)測(cè)樹高計(jì)算該競(jìng)爭(zhēng)指數(shù)的可行性，以期給出基于交角的林木競(jìng)爭(zhēng)指數(shù)的最優(yōu)經(jīng)驗(yàn)計(jì)算途徑。【方法】 以3個(gè)地區(qū)共6塊樣地的天然林和人工林為研究對(duì)象，利用全站儀測(cè)定并記錄林木坐標(biāo)、樹種、胸徑、樹高、冠幅和健康狀況，并計(jì)算和分析各樣地林木通過(guò)胸徑得到的競(jìng)爭(zhēng)指數(shù)(CID)，通過(guò)胸徑-樹高曲線預(yù)估樹高后得到的競(jìng)爭(zhēng)指數(shù)(CID-H)與通過(guò)實(shí)測(cè)樹高得到的競(jìng)爭(zhēng)指數(shù)(CIH)間的關(guān)系?！窘Y(jié)果】 不同森林類型林分通過(guò)胸徑和胸徑-樹高曲線預(yù)估樹高后計(jì)算得到林木競(jìng)爭(zhēng)指數(shù)的2個(gè)經(jīng)驗(yàn)計(jì)算途徑都是可行的，且都能表達(dá)出通過(guò)實(shí)測(cè)樹高計(jì)算得到林木競(jìng)爭(zhēng)指數(shù)(CIH)結(jié)果的95%以上。2個(gè)經(jīng)驗(yàn)計(jì)算途徑的效果與胸徑-樹高曲線模型精度呈顯著正相關(guān)，當(dāng)胸徑-樹高曲線模型精度低(R2<0.53)時(shí)，CID-H效果略差?！窘Y(jié)論】 由于CID-H計(jì)算過(guò)程較復(fù)雜，且當(dāng)林分胸徑-樹高曲線模型精度較低時(shí)，競(jìng)爭(zhēng)指數(shù)CID-H的應(yīng)用效果比競(jìng)爭(zhēng)指數(shù)CID略差，因此以胸徑替代實(shí)測(cè)樹高可作為該競(jìng)爭(zhēng)指數(shù)的最佳經(jīng)驗(yàn)計(jì)算途徑。

[關(guān)鍵詞]基于交角的林木競(jìng)爭(zhēng)指數(shù)；胸徑-樹高曲線模型；經(jīng)驗(yàn)計(jì)算途徑

林木的微環(huán)境取決于林分的結(jié)構(gòu)，林分結(jié)構(gòu)是決定林木生態(tài)位的關(guān)鍵要素，林木的活力由林木本身的遺傳因素及其所處的微環(huán)境決定。在生態(tài)學(xué)中林木的活力通過(guò)競(jìng)爭(zhēng)來(lái)表達(dá)。競(jìng)爭(zhēng)指兩個(gè)或多個(gè)植物體對(duì)同一環(huán)境資源和能量爭(zhēng)奪中的相互作用[1]，這意味著由于相鄰競(jìng)爭(zhēng)木的存在而使環(huán)境資源減少，從而使鄰近有機(jī)體之間互相影響和阻礙，競(jìng)爭(zhēng)的結(jié)果產(chǎn)生了植物個(gè)體生長(zhǎng)發(fā)育上的差異[2]。競(jìng)爭(zhēng)現(xiàn)象在植物群落中普遍存在，并且對(duì)植物群落的結(jié)構(gòu)及其演替進(jìn)程具有重要影響，一直是生態(tài)學(xué)家研究的熱點(diǎn)之一。

競(jìng)爭(zhēng)指數(shù)是描述林木間競(jìng)爭(zhēng)關(guān)系的一種數(shù)學(xué)表達(dá)式，反映林木所承受的競(jìng)爭(zhēng)壓力，這取決于林木自身狀態(tài)(如胸徑、樹高和冠幅等)及其所處的局部環(huán)境(鄰近樹木的狀態(tài))[3]。當(dāng)前，競(jìng)爭(zhēng)指數(shù)一般可分為與距離有關(guān)的競(jìng)爭(zhēng)指數(shù)和與距離無(wú)關(guān)的競(jìng)爭(zhēng)指數(shù)[4-9]。與距離有關(guān)的競(jìng)爭(zhēng)指數(shù)能精確估測(cè)林木生長(zhǎng)，并有助于提高林木生長(zhǎng)和發(fā)育生長(zhǎng)模型的預(yù)估效果，因此近年來(lái)得到廣泛發(fā)展。由于林木地下部分的競(jìng)爭(zhēng)分散且難預(yù)測(cè)，與距離有關(guān)的競(jìng)爭(zhēng)研究主要集中在地上部分[10]，如從樹冠范圍尺度上研究競(jìng)爭(zhēng)的樹冠面積重疊競(jìng)爭(zhēng)指數(shù)[11-14]、光照競(jìng)爭(zhēng)指數(shù)[15]等，考慮林木樹高研究競(jìng)爭(zhēng)的高度角競(jìng)爭(zhēng)指數(shù)[16]和樹高大小比值競(jìng)爭(zhēng)指數(shù)[17]等，基于林木胸徑大小對(duì)空間擠占提出的Hegyi簡(jiǎn)單競(jìng)爭(zhēng)指數(shù)[18]、復(fù)雜競(jìng)爭(zhēng)指數(shù)[19-20]等?；輨傆萚2]綜合考慮了林木的樹高和胸徑大小，基于交角原理、以大小比數(shù)為權(quán)重提出了基于交角的林木競(jìng)爭(zhēng)指數(shù)，其生物學(xué)意義在于對(duì)象木所受到的競(jìng)爭(zhēng)壓力在距離保持不變時(shí)隨競(jìng)爭(zhēng)木樹高的增加呈非線形增加，或在競(jìng)爭(zhēng)木樹高一定時(shí)隨距離的變遠(yuǎn)而呈非線性減小，簡(jiǎn)潔地表達(dá)出競(jìng)爭(zhēng)木上方的遮蓋和側(cè)翼的擠壓。由于林木胸徑在林分中測(cè)定簡(jiǎn)單、方便、準(zhǔn)確且花費(fèi)低，所以通常的競(jìng)爭(zhēng)指數(shù)(如Hegyi指數(shù)、BAL指數(shù)[21])都直接包含或隱含胸徑變量。在林分中測(cè)定林木樹高難度較大、速度較慢且誤差較大，給基于交角的林木競(jìng)爭(zhēng)指數(shù)實(shí)際應(yīng)用帶來(lái)較大困難。為解決上述問(wèn)題，本研究選取3個(gè)地區(qū)共6塊樣地的天然林和人工林，探討不同林分用胸徑或通過(guò)胸徑-樹高曲線預(yù)估樹高后替代實(shí)測(cè)樹高計(jì)算該競(jìng)爭(zhēng)指數(shù)的可行性，以期給出基于交角的林木競(jìng)爭(zhēng)指數(shù)的經(jīng)驗(yàn)計(jì)算途徑。

1材料與方法

1.1研究區(qū)概況

本研究以天然林和人工林樣地為試驗(yàn)對(duì)象，其中天然林試驗(yàn)樣地分別位于吉林蛟河和甘肅小隴山。人工林樣地位于北京市九龍山自然保護(hù)區(qū)。

在吉林省蛟河林業(yè)試驗(yàn)區(qū)管理局東大坡自然保護(hù)區(qū)內(nèi)(127°35′～127°51′ E，43°51′～44°05′ N)設(shè)置2 塊永久性樣地(表1中1號(hào)和2號(hào)樣地)，境內(nèi)平均海拔在400～500 m，地勢(shì)為東北部山高坡陡，而西南部地勢(shì)平緩。該區(qū)屬溫帶大陸性季風(fēng)山地氣候，全年平均氣溫1.7 ℃，降雨集中在6-8月份，年均降水量700～800 mm，無(wú)霜期120～150 d，平均積雪厚度20～60 cm，土壤結(jié)凍深度1.5～2 m，土壤為暗棕壤。

在甘肅省南部小隴山百花林場(chǎng)(104°22′～105°43′ E，33°30′～34°40′ N)設(shè)置2 塊永久性樣地(表1中3號(hào)和4號(hào)樣地)，境內(nèi)海拔在700～2 500 m。該區(qū)屬暖溫濕潤(rùn)-中溫半濕潤(rùn)大陸性季風(fēng)氣候，年平均氣溫7～12 ℃，年均降水量600～900 mm，年日照時(shí)數(shù)1 520～2 313 h，無(wú)霜期130～220 d，區(qū)內(nèi)秦嶺以北的土壤為灰褐土，以南為黃褐土。

在北京市門頭溝區(qū)九龍山自然保護(hù)區(qū)(115°59′～116°06′ E，39°54′～39°57′ N)內(nèi)設(shè)置2塊永久性樣地(表1中5號(hào)和6號(hào)樣地)，境內(nèi)海拔在400～1 000 m。該區(qū)屬大陸性東岸季風(fēng)氣候，年平均氣溫11～12 ℃，年均降水量600～700 mm，年日照時(shí)數(shù)2 500～2 700 h，無(wú)霜期190～200 d，區(qū)內(nèi)400 m以下為山地粗骨褐土，400 m以上為山地淋溶褐土。

1.2樣地設(shè)置與調(diào)查

不同地區(qū)永久性樣地設(shè)置面積見表1，對(duì)樣地內(nèi)所有胸徑≥5 cm的林木進(jìn)行掛牌標(biāo)號(hào)，利用全站儀(TOPCON-GTS-602AF)測(cè)定并記錄林木坐標(biāo)、樹種、胸徑、樹高、冠幅和健康狀況等。

表 1　本研究設(shè)置的6塊樣地概況Table 1　General conditions of six sample plots in this study

1.3數(shù)據(jù)分析方法

1.3.1胸徑-樹高曲線模型本研究使用比較常用的胸徑-樹高曲線模型(表2)，應(yīng)用SPSS 18.0軟件擬合6塊樣地核心區(qū)域數(shù)據(jù)，根據(jù)P 值判斷回歸模型的可行性，最后利用模型決定系數(shù)R2確定最優(yōu)模型。

表 2　胸徑-樹高曲線模型Table 2　Height-diameter model

注：H為樹高；D為胸徑；a,b,c為參數(shù)。

Note:Hrepresents tree height；Drepresents diameter at breast height (DBH)；a,b,andcare parameters.

1.3.2基于交角的林木競(jìng)爭(zhēng)指數(shù)為便于表述，本研究將惠剛盈等[2]提出的用實(shí)測(cè)樹高計(jì)算基于交角的林木競(jìng)爭(zhēng)指數(shù)(u_α_CIi)簡(jiǎn)寫為CIH，將利用胸徑-樹高曲線模型預(yù)估的樹高代替實(shí)測(cè)樹高計(jì)算基于交角的林木競(jìng)爭(zhēng)指數(shù)簡(jiǎn)寫為CID-H，將胸徑直接代替樹高計(jì)算基于交角的林木競(jìng)爭(zhēng)指數(shù)簡(jiǎn)寫為CID，計(jì)算公式如下：

式中：Hi為對(duì)象木的實(shí)測(cè)或預(yù)估樹高，Hj為相鄰木的實(shí)測(cè)或預(yù)估樹高，Di為對(duì)象木的胸徑，Dj為相鄰木的胸徑，Lij為對(duì)象木和相鄰木之間的距離，n為結(jié)構(gòu)單元內(nèi)相鄰木的株數(shù)。

應(yīng)用Visual Basic高級(jí)程序設(shè)計(jì)語(yǔ)言，以對(duì)象木和最近4株相鄰木作為一個(gè)結(jié)構(gòu)單元，編制計(jì)算基于交角的林木競(jìng)爭(zhēng)指數(shù)程序。為避免邊緣效應(yīng)對(duì)林分結(jié)構(gòu)的影響，計(jì)算時(shí)緩沖區(qū)設(shè)置為5 m。

2結(jié)果與分析

2.1各樣地胸徑-樹高曲線模型的確定

所有樣地?cái)M合的胸徑-樹高曲線模型均通過(guò)了顯著性檢驗(yàn)(P<0.001)(表3)，模型的決定系數(shù)R2為0.497～0.849，擬合的胸徑-樹高曲線均呈現(xiàn)隨著胸徑的增大樹高先增后趨于穩(wěn)定的趨勢(shì)。除樣地3的最優(yōu)胸徑-樹高曲線模型為冪函數(shù)外，其余樣地的最佳模型均為拋物線函數(shù)。排列各樣地決定系數(shù)R2，依次為樣地4(0.849)>樣地3(0.799)>樣地1(0.721)>樣地6(0.545)>樣地2(0.529)>樣地5(0.497)。

表 3　各樣地最佳胸徑-樹高曲線模型的模擬結(jié)果Table 3　Best simulation results of height-diameter model in each plot

2.2通過(guò)3種途徑計(jì)算得到的競(jìng)爭(zhēng)指數(shù)間的關(guān)系

從6塊樣地的競(jìng)爭(zhēng)指數(shù)CIH與CID(圖1)或CID-H(圖2)的回歸分析可以看出，CIH與二者之間具有高度相關(guān)性，其決定系數(shù)R2均大于0.95，說(shuō)明CID和CID-H可以表達(dá)出CIH結(jié)果的95%以上。二者關(guān)系可用線性函數(shù)CIH=bCID或CIH=bCID-H進(jìn)行表達(dá)，因?yàn)榫€性函數(shù)系數(shù)b∈(0,1)，且CIH∈[0,1)[2]，所以CIH

圖 1　6塊樣地競(jìng)爭(zhēng)指數(shù)CIH與CID之間的關(guān)系Fig.1　Relationship between competition indexes of CIH and CID in the six plots

圖 2　6塊樣地競(jìng)爭(zhēng)指數(shù)CIH與CID-H之間的關(guān)系Fig.2　Relationship between competition indexes of CIH and CID-H in the six plots

CIH與競(jìng)爭(zhēng)指數(shù)CID或CID-H之間的R2與樣地內(nèi)所有樹種擬合的胸徑-樹高曲線模型R2均呈顯著正相關(guān)(表4)，即當(dāng)胸徑與樹高相關(guān)程度越高，則競(jìng)爭(zhēng)指數(shù)CIH與CID或CID-H之間的相關(guān)程度就越大。對(duì)比各樣地CIH與CID或CID-H之間的決定系數(shù)R2，發(fā)現(xiàn)樣地1、3、4、6的CIH與CID-H之間的R2都大于CIH與CID之間的R2，但樣地2、5則相反。從表3可以看出，在樣地2、5中，擬合的胸徑-樹高曲線模型精度低(R2小于0.53)，使得預(yù)估樹高與實(shí)測(cè)樹高之間誤差增大，因而使計(jì)算所得的競(jìng)爭(zhēng)指數(shù)CID-H與CIH之間的相關(guān)程度降低。由此可見，以胸徑直接替代樹高能更穩(wěn)定有效地計(jì)算該林木競(jìng)爭(zhēng)指數(shù)。

表 4　胸高關(guān)系與競(jìng)爭(zhēng)指數(shù)間關(guān)系的相關(guān)分析Table 4　Correlation analysis between height-diameter model and each CI

注：*代表決定系數(shù)顯著(P<0.05)。

Note:* represents the correlation between determination coefficients is significant (P<0.05).

2.3各樣地競(jìng)爭(zhēng)指數(shù)與對(duì)象木胸徑間的關(guān)系

不同生長(zhǎng)階段的林木個(gè)體大小不同，也可反映出不同的競(jìng)爭(zhēng)能力。大量研究[2,22-23]表明，大的林木具有強(qiáng)的競(jìng)爭(zhēng)能力，即樹體越大，所承受的競(jìng)爭(zhēng)壓力越小，二者服從冪函數(shù)關(guān)系[24-26]，6 塊樣地?cái)M合的競(jìng)爭(zhēng)指數(shù)與林木胸徑大小的關(guān)系進(jìn)一步證實(shí)了這一規(guī)律(圖3和圖4)。由圖3和圖4可以看出，競(jìng)爭(zhēng)指數(shù)CIH與林木胸徑大小的相關(guān)程度相對(duì)高于CID的，但二者對(duì)6塊樣地?cái)M合結(jié)果的趨勢(shì)是一致的，均為樣地6>樣地3>樣地5>樣地2>樣地1>樣地4。由此可見，競(jìng)爭(zhēng)指數(shù)CID能替代CIH有效地表達(dá)出不同大小的林木所承受的競(jìng)爭(zhēng)壓力。

圖 3　6塊樣地競(jìng)爭(zhēng)指數(shù)CIH與生長(zhǎng)因子的相關(guān)性Fig.3　Correlation between competition index CIH and growth factor in the six plots

圖 4　6塊樣地競(jìng)爭(zhēng)指數(shù)CID與生長(zhǎng)因子的相關(guān)性Fig.4　Correlation between competition index CID and growth factor in the six plots

3結(jié)論與討論

(1)用胸徑直接替代基于交角的林木競(jìng)爭(zhēng)指數(shù)中的樹高是可行的。CID和CIH都能有效地表達(dá)出不同大小的林木所承受的競(jìng)爭(zhēng)壓力，競(jìng)爭(zhēng)指數(shù)最高的是小樹，因而小樹承載的競(jìng)爭(zhēng)壓力最大，其次是中樹，而大樹的競(jìng)爭(zhēng)指數(shù)最低[2,22-23]。雖然競(jìng)爭(zhēng)指數(shù)CIH與胸徑的擬合精度稍高于CID的，但二者對(duì)6塊樣地的擬合結(jié)果趨勢(shì)是一致的。

(2)基于交角的林木競(jìng)爭(zhēng)指數(shù)在實(shí)際應(yīng)用中可用樹高曲線間接途徑進(jìn)行計(jì)算，但應(yīng)用效果取決于樹高曲線模型的精度，當(dāng)胸徑-樹高曲線模型精度較低時(shí)，競(jìng)爭(zhēng)指數(shù)CID-H并沒(méi)有比競(jìng)爭(zhēng)指數(shù)CID更好地反映林木的競(jìng)爭(zhēng)，因此，以胸徑替代實(shí)測(cè)樹高可作為該競(jìng)爭(zhēng)指數(shù)的最佳經(jīng)驗(yàn)計(jì)算途徑。

圖 56塊樣地競(jìng)爭(zhēng)指數(shù)與對(duì)象木胸徑等級(jí)的關(guān)系

Fig.5Relationship between competition index and objective tree DBH classes in the six plots

(3)競(jìng)爭(zhēng)指數(shù)CIH

[參考文獻(xiàn)]

[1]辛營(yíng)營(yíng),韋新良.青山湖針闊混交林優(yōu)勢(shì)樹種競(jìng)爭(zhēng)的數(shù)量研究 [J].浙江農(nóng)林大學(xué)學(xué)報(bào),2011,28(4):601-606.

Xin Y Y,Wei X L.Dominance in a mixed conifer and broadleaved forest of Qingshan Lake [J].Journal of Zhejiang Forestry College,2011,28(4):601-606.

[2]惠剛盈,胡艷波,趙中華,等.基于交角的林木競(jìng)爭(zhēng)指數(shù) [J].林業(yè)科學(xué),2013,49(6):68-73.

Hui G Y,Hu Y B,Zhao Z H,et al.A forest competition index based on intersection angle [J].Scientia Silvae Sinicae,2013,49(6):68-73.

[3]唐守正,李希菲,孟昭和.林分生長(zhǎng)模型研究的進(jìn)展 [J].林業(yè)科學(xué)研究,1993,6(6):672-679.

Tang S Z,Li X F,Meng Z H.The development of studies on stand growth models [J].Forest Research,1993,6(6):672-679.

[4]邵國(guó)凡.紅松人工林單木生長(zhǎng)模型的研究 [J].東北林業(yè)大學(xué)學(xué)報(bào),1985,13(3):38-46.

Shao G F.Research on individual growth model ofPinuskoraiensisartificial forest [J].Journal of Northwest Forestry University,1985,13(3):38-46.

[5]張躍西.鄰體干擾模型的改進(jìn)及其在營(yíng)林中的應(yīng)用 [J].植物生態(tài)學(xué)與地植物學(xué)學(xué)報(bào),1993,17(4):352-357.

Zhang Y X.Application and improvement of the neighborhood interference model [J].Acta Phytoecologicaet Geobotanica Sinica,1993,17(4):352-357.

[6]孟憲宇.測(cè)樹學(xué) [M].3版.北京:中國(guó)林業(yè)出版社,1996:88-288.

Meng X Y.Forest mensuration [M].3th ed.Beijing:China Fo-restry Publishing,1996:88-288.

[7]Weiner J.Neighborhood interference amongstPinusrigidaindividuals [J].The Journal of Ecology,1984,72(1):183-195.

[8]Tomé M,Burkhart H E.Distance-dependent competition measures for predicting growth of individual trees [J].Forest Science,1989,35(3):816-831.

[9]Biging G S,Dobbertin M.Evaluation of competition indices in individual tree growth models [J].Forest Science,1995,41(2):360-377.

[10]Daniels R F.Notes:simple competition indices and their correlation with annual loblolly pine tree growth [J].Forest Science,1976,22(4):454-456.

[11]Gerrard D J.Competition quotient:a new measure for the competition affecting individual forest trees [C].East Lansing:Agricultural Experiment Station,Michigan State University,1969:1-32.

[12]Bella I E.A new competition model for individual trees [J].Forest Science,1971,17(3):364-372.

[13]Arney J D.Tables for quantifying competitive stress on individual trees [R].Columbia:Pacific Forest Research Centre,1973.

[14]Ekar.Forest:a computer model for simulating the growth and reproduction of mixed-species forest stands [M].Madison:School of Natural Resources,College of Agricultural and Life Sciences,University of Wisconsin,1974.

[15]Contreras M A,Affleck D,Chung W.Evaluating tree competition indices as predictors of basal area increment in western Montana forests [J].Forest Ecology and Management,2011,262(11):1939-1949.

[16]Rautiainen O.Growth dynamics and management of Shorearobusta forests in Southern Nepal [D].Tulliportinkatu:University of Joensuu,1999.

[17]Pukkala T,Kolstr?m T.Competition indices and the prediction of radial growth in Scots pine [J].Silva Fennica,1987,21(1):55-67.

[18]Hegyi F.A simulation model for managing jack-pine stands,growth models for tree and stand simulation [J].Forest Research,1974(30):74-90.

[19]Alemdag I S.Evaluation of some competition indexes for the prediction of diameter increment in planted white spruce [R].Ottawa:Canadian Forestry Service,Department of the Environment,1978.

[20]Martin G L,Ek A R.A comparison of competition measures and growth models for predicting plantation red pine diameter and height growth [J].Forest Science,1984,30(3):731-743.

[21]Wykoff W R.A basal area increment model for individual conifer in the northern Rocky Mountains [J].Forest Science,1990,36(4):1077-1104.

[22]伍澤文.杉木厚樸混交林木鄰體競(jìng)爭(zhēng)的研究 [J].河南農(nóng)業(yè)大學(xué)學(xué)報(bào),2006,40(1):31-34.

Wu Z W.A study on adjacent wood competition in mixed plantation ofCunninghamialanceolataandMagnoliaofficinalis[J].Journal of Henan Agricultural University,2006,40(1):31-34.

[23]殷東生,葛文志,張鳳海,等.色木槭天然次生林種群競(jìng)爭(zhēng)關(guān)系研究 [J].植物研究,2012,32(1):105-109.

Yin D S,Ge W Z,Zhang F H,et al.Competition relationship of populations of natural secondaryAcermonoforest [J].Bulletin of Botanical Research,2012,32(1):105-109.

[24]胡剛,梁士楚,張忠華,等.桂林巖溶石山青岡櫟種內(nèi)與種間競(jìng)爭(zhēng)的數(shù)量關(guān)系 [J].西北林學(xué)院學(xué)報(bào),2007,22(5):32-36.

Hu G,Liang S C,Zhang Z H,et al.Quantitative relationship of intraspecific and interspecific competition inCyclobalanopsisglaucain Krast Hills in Guilin [J].Journal of Northwest Forest University,2007,22(5):32-36.

[25]鄒春靜,徐文鐸.沙地云杉種內(nèi)、種間競(jìng)爭(zhēng)的研究 [J].植物生態(tài)學(xué)報(bào),1998,22(3):269-274.

Zou C J,Xu W D.Study on intraspecific and interspecific competition ofPiceamongolica[J].Chinese Journal of Plant Ecology,1998,22(3):269-274.

[26]張思玉,鄭世群.筆架山常綠闊葉林優(yōu)勢(shì)種群種內(nèi)種間競(jìng)爭(zhēng)的數(shù)量研究 [J].林業(yè)科學(xué),2009,37(S1):185-188.

Zhang S Y,Zheng S Q.Quantitative study on intraspecific and interspecific competition for dominant population of evergreen broad-leaved forest in Bijia Mountain [J].Scientia Silvae Sinicae,2009,37(S1):185-188.

[27]金則新,朱小燕,林恒琴.浙江天臺(tái)山甜櫧種內(nèi)與種間競(jìng)爭(zhēng)研究 [J].生態(tài)學(xué)雜志,2004,32(2):22-25.

Jin Z X,Zhu X Y,Lin H Q.Intraspecific and interspecific competition inCastanopsiseyreiin Tiantai Mountain of Zhejiang Province [J].Chinese Journal of Ecology,2004,32(2):22-25.

[28]趙西平,余建基,張超男,等.黑龍江省帽兒山林場(chǎng)天然白樺林優(yōu)勢(shì)生長(zhǎng)過(guò)程研究 [J].西北林學(xué)院學(xué)報(bào),2014,29(2):191-195.

Zhao X P,Yu J J,Zhang C N,et al.Growth process ofBetulaplatyllain natural forest in northwest China [J].Journal of Northwest Forestry University,2014,29(2):191-195.

[29]吳敏,李春葉,秦武明,等.72年生細(xì)葉云南松天然林生長(zhǎng)規(guī)律研究 [J].廣東農(nóng)業(yè)科學(xué),2014,41(2):61-65.

Wu M,Li C Y,Qin W M,et al.The growth rhythm of 72-year-oldPinusyunnanensisvar.natural forest [J].Guangdong Agricultural Sciences,2014,41(2):61-65.

[30]余楊春,袁彩霞.六盤山華北落葉松人工林生長(zhǎng)規(guī)律研究 [J].農(nóng)業(yè)科學(xué)研究,2014,35(3):16-22.

Yu Y C,Yuan C X.A study on the characteristics of stand growth ofLarixprincipis-rupprechtiiplantation in Liupan Mountains [J].Journal of Agricultural Sciences,2014,35(3):16-22.

DOI：網(wǎng)絡(luò)出版時(shí)間:2016-06-0816:2110.13207/j.cnki.jnwafu.2016.07.020

[收稿日期]2014-12-05

[基金項(xiàng)目]國(guó)家自然科學(xué)基金項(xiàng)目(31370638)

[作者簡(jiǎn)介]白超(1988-)，女(彝族)，云南建水人，在讀博士，主要從事森林空間結(jié)構(gòu)研究。E-mail:baichao928@163.com [通信作者]胡艷波(1975-)，女，遼寧寬甸人，助理研究員，主要從事森林經(jīng)營(yíng)研究。E-mail:hyanbo@caf.ac.cn

[中圖分類號(hào)]S758

[文獻(xiàn)標(biāo)志碼]A

[文章編號(hào)]1671-9387(2016)07-0138-08

Application of forest competition index based on intersection angle

BAI Chao,ZHAO Zhonghua,HU Yanbo

(KeyLaboratoryofTreeBreedingandCultivationofStateForestryAdministration,ResearchInstituteofForestry,ChineseAcademyofForestry,Beijing100091,China)

Abstract:【Objective】 Forest competition index (CI) based on intersection angle is concise and able to express the over shading and the lateral extruding from the competitive trees.The feasibility of two empirical calculation methods using DBH (D) directly or using estimated tree height from diameter-height (D-H) curve model was discussed to provide optimal empirical calculation of forest competition index based on intersection angle.【Method】 Six sample plots in natural and artificial forests of 3 regions were selected and trees coordinates,species,DBH,tree height,crown width and health were measured and recorded using electronic total station.Then the relationship between competition index calculated by DBH (CID),tree height estimated with diameter-height curve model (CID-H) and measured tree height (CIH) was analyzed.【Result】 It was feasible to use the two empirical calculation methods to calculate competition indexes of different forests with more than 95% identity compared with measured tree height (CIH).The effects of two empirical calculation methods were significantly positively related to the accuracy of tree DBH and tree height model.When the correlation between tree DBH and tree height was low (R2<0.53),the accuracy of CID-Hwas slightly worse than that of CID.【Conclusion】 Because of complicated calculation process of CID-H,the results of CID-Hwere slightly better than that of CID when correlation between tree DBH and height was low.Therefore,using DBH directly is the optimal calculation method for forest competition index based on intersection angle.

Key words:forest competition index based on intersection angle;height-diameter curve model;empirical calculation way

網(wǎng)絡(luò)出版地址:http://www.cnki.net/kcms/detail/61.1390.S.20160608.1621.040.html