【作者】 张令峰；

【导师】 傅松玲；

【作者基本信息】 安徽农业大学 ， 森林培育， 2013， 博士

【摘要】 马尾松(Pinus massoniana Lamb)是我国亚热带分布最广、资源最多的针叶树种,也是我国南方林区主要的工业用材树种。林业实践证明,长期进行马尾松纯林经营,导致林分生产力下降、生态功能差、松毛虫害猖獗、地力衰退、防火能力弱等一系列问题。马尾松针阔混交林能有效利用光能和全面利用土壤肥力,改善林分状况,提高林分生产力。本研究自2007年起,在安徽省枞阳县大山村采用固定样地调查法,以不同混交比例马尾松林为研究对象,按照马尾松胸高断面积所占比例将调查林分划分为0-20%,20-40%,40-60%,60-80%和80-100%类型,研究混交比例对林分生物量、植物碳量、土壤有机碳、物种多样性、林下植被生产力、根系以及土壤理化性质的影响。主要结果如下：1.乔木层(1)主要乔木树种树木解析结果表明,马尾松各器官和地上部分及全株生物量与生长指标的关系模型为w干=53.69704+0.01025×(D2H)、1nW皮=-16.24899+9.89795·lnD-0.58846·D、lnW枝=6.18119-1.60294.1nD-0.75932.ln(H/D)、w地上=-14.63286+40.72698·lnD、W全株=6.1435+39.05153·ln D:而化香(P1atycarya strobilacea Sieb.et Zucc)各器官和地上部分及全株生物量模型为1nW干:0.55883+0.70839·lnD-1.98923·ln(H/D).W皮=1.6635·D0.07566、lnW枝=6.87613-0.703524·lnD+3.40175·ln(H/D)、1nW叶=4.58771+0.20155·1nD+5.19331·ln(H/D).1nW地上=9.99853-3.73503·lnD+0.28907.D、lnW全株=10.48087-3.85889· lnD+0.29122·D。为乔木树种生物量及森林碳的计量提供捷径。(2)随着马尾松混交比例的增加,乔木层总生物量不断变化,其由大到小排序所在林分混交比例分别为：40-60%>20-40%>60-80%>80-100%>0-20%。当马尾松所占比例为40-60%时,林分总生物量最大,为123.36t·hm-2当混交比例为0-20%时,林分总生物量最低,仅有81.79t·hm-2。乔木层生物量一定程度上决定了林分总生物量的分布趋势。2.草灌层(3)随混交比例的变化,灌木层生物量差异显著(P<0.01)。林分灌木层生物量由大到小的混交比例分别为：40-60%>20-40%>0-20%>80-100%>60-80%。其中混交比例为40-60%的林分和60-80%的林分,最高1.36t.hm-2,最低0.98t.hm-2。(4)混交比例对林分中的灌木层与草本层植物种类组成结构具有差异性。灌木层物种丰富度随着马尾松所占比例的增加呈现先增加后减少的趋势(丰富度最大值出现在混交比例为40-60%的林分中),而草本层物种丰富度几乎不随马尾松所占比例的变化而变化；草本层盖度相对稳定,而灌木层盖度呈现逐渐降低趋势；草本层高度缓慢降低,而灌木层高度波动性变化。混交比例对林下植被多样性指数影响较为显著,灌木层植物的Shannon-Wiener指数和Margalef指数大小顺序排列皆为：80-100%<0-20%<20-40%<60-80%<40-60%。(5)林下总生物量与灌木层生物量、灌木层多样性指数和丰富度指数具有显著正相关关系,部分达到极显著正相关关系；草本层生物量与灌木层生物量呈显著负相关关系；草本层生物量与草本植物多样性及丰富度均显著正相关。不同比例的混交林中,草层生物量只占林下生物量比例的5-18%,而灌本层占较大部分,林下植被生物量随着混交比例的增加呈现先增大后降低的趋势。在5种混交比例林分中,灌木层生物量占林下总生物量比例从小到大的排序为：60-80%<80-100%<0-20%<20-40%<40-60%。3.地下部分(6)研究地区马尾松混交林根系(d<10mm)生物量均值为1.693t·hm-2。随混交比例的变化,细根生物量不断变化,林分内细根生物量大小梯度为：40-60%>0-20%>20-40%>80-100%>60-80%。细根生物量占根系总生物量大小依次为：40-60%>20-40%>0-20%>80-100%>60-80%。说明马尾松混交比例为40-60%的林分,土壤结构良好,有机质含量较高,进而增加了细根的生物量,提高了群落物种丰富度。(7)林下总生物量、灌木层生物量以及草木层生物量与上壤孔隙度呈正相关关系,与土壤容重呈负相关关系,其中林下总生物量与两者分别有显著的正相关和显著的负相关。土壤含水量对灌木层生物量有一定的影响,但并未达到显著水平,土壤容重对草本层、灌木层生物量有较弱的负效应。林下草本层、灌木层的Shannon-Wiener指数和Margalef指数与土壤的含水量、有机质、pH、全钾、全氮、全磷以及速效钾、速效磷则呈现出不同程度的正相关性,但都未达到显著水平。灌木层的Shannon-Wiener指数、Margalef指数与上壤的容重呈现负相关关系,而且相关系数较高,分别达到0.432和0.456。(8)在0-10cm上层中,细根生物量与全磷、速效磷、有机质及上壤孔隙度关系呈极显著正相关(P<0.01),与含水量呈显著正相关(P<0.05)。比根长对土壤全钾和全氮呈显著负相关(P<0.05),细根根密度和土壤孔隙度呈显著正相关(P<0.05)；在10-20cm上层中,细根生物量与全磷、有机质、含水量及土壤孔隙度均呈极显著正相关(P<0.01),与速效钾呈显著正相关(P<0.05)。比根长与速效钾和全钾呈显著负相关(P<0.05)；在20-30cm土层中,细根生物量与速效钾、有机质、含水量及上壤孔隙度均呈极显著正相关(P<0.01),与全钾呈显著正相关(P<0.05)。根密度与全钾呈显著正相关(P<0.05),比根长与全磷呈负相关。4.混交林生态系统(9)马尾松单株各营养器官生物量分配差异较大,各器官生物量的分配规律为树干>树根>树枝>树皮>树叶。马尾松标准木单株、地上部分和树干的生物量最大值分别为114.69kg、98.48kg、77.83kg,都出现在马尾松混交比例为40-60%的林分中；最小值都出现在0-20%混交比例的林分中,分别为102.8kg、86.01kg、63.57kg。马尾松单株及其各营养器官的生物量与胸径和树高呈现正相关关系,在同一树龄下随胸径和树高的增大而增大。马尾松根的生物量占单株生物量15%左右,是各器官生物量所占全株生物量的比例变化幅度最小的。化香单株生物量与胸径和树高呈正相关关系,随胸径和树高的增大而增大。化香单株和地上部分生物量最大值分别为97.03Kg、82.56kg,出现在混交比例为20-40%的混交林中；单株和地上部分生物量最小值分别为79.97Kg、65.21kg,出现在混交比例为60-80%的林分中。化香树干生物量所占的比例是最大的,其次是枝,且枝与干的变化趋势呈现负相关,枝与叶的变化趋势则呈现出正相关性。(10)马尾松不同混交比例林分的碳贮量差异较为明显。林分碳贮量大小梯度为：40-60%>20-40%>60-80%>80-100%>0-20%。混交比例为40-60%的林分的碳贮量最高的,可达61.92t·hm-2。枯落物及粗死木碳贮量最大值出现在马尾松所占比例为40-60%的林分,高达2.15t·hm-2,远远高于其它混交比例林分。各混交比例林分的枯落物及粗死木碳量远远大于灌木层碳贮量,可见枯落物及粗死木是碳汇的重要部分。实验结果表明,研究区域内随混交比例的增加,土壤碳密度按从大到小排列依次为：40-60%>60-80%>20-40%>80-100%>0-20%。更多还原

【Abstract】 Masson pine (Pinus massoniana Lamb.) is a main coniferous tree species in subtropical area. It is the major industrial timber species in China. Forestry practice has been proved that pure pine forest couse series of problems such as decline in forest productivity, weak ecological function, rampant of pine moth, soil fertility decline, and weak fire prevention ability. Mixedwood can effectively utilize light energy and soil, to improve forest productivity. ZongYang County, Anhui province belongs to subtropical monsoon climate zone and the four season’s climate changes obviously. The mixedwood of conifer with deciduous broad leaved tree is the main vegetation types in the area. This paper researched different proportion of Masson pine mixed forest since2007. The forest biomass, plant carbon, soil organic carbon, biodiversity, undergrowth, root and soil had been studied. The results showed as follows:1. Tree layer(1) The main arbor tree trunk analytical results show that Masson pine aerial parts of each organ and whole plant biomass and growth indicators and the relationship between model for Wtrunk=53.69704+0.01025×(D2H)、lnW skin=-16.24899+9.89795·lnD-0.58846·D、 lnWbranch=6.18119-1.60294·lnD-0.75932·ln(H/D)、Waboveground=-14.63286+40.72698·lnD、 Wplant=6.1435+39.05153·lnD; And each organ and aboveground part and whole plant biomass model for lnWtrunk=0.55883+0.70839·lnD-1.98923·ln(H/D)、Wsin=1.6635·D0.07566、 lnWbranch==6.87613-0.703524·lnD+3.40175·ln(H/D)、lnWleaf=4.58771+0.20155·lnD+5.19331·ln(H/D)、 lnWaboveground=9.99853-3.73503·lnD+0.28907·D、lnWplant=10.48087-3.85889·lnD+0.29122·D. Tree species for biomass and forest carbon measurement provide shortcuts.(2) With the increase of Masson pine mixed proportion, the stand total above ground biomass changes unceasingly. The stand total above ground biomass gradient and mixed proportion relations as follows:40-60%>20-40%>60-80%>80-100%>0-20%.When the proportion of Massion pine is40-60%, the total above ground biomass is biggest with about123.36t-hm-2. While pine mixing proportion is80-100%, the total above ground biomass is lowest with only81.79t·hm-2. Tree layer biomass to a certain extent determines the distribution trend of the total stand above ground biomass.2. Herbs and shrubs layer(3) With the change of Masson pine mixed proportion, the shrub layer biomass is significant different (P<0.01). The biggest is0.97t.hm-2in the forest with Masson pine60-80%, followes by40-60%,20-40%,80-100%and0-20%successively. The mixed ratio of60-80%has lowest shrub biomass of0.98t. hm-2. The mixed ratio of20-40%has highest shrub biomass of1.36t.hm-2.(4) Different mixed proportion leads to different shrub and herb structures. The study showes a trend of decrease after the first increase that the shrub layer species richness increased with the increase of proportion of Masson pine; herb layer species richness almost not change along with the change of proportion of Masson pine; the shrub layer coverage showed a trend of gradually reduce; herb layer’s height down slowly, shrub layer’s hight volatility changes. Mixed proportion significantly effect on undergrowth biodiversity index. The Shannon-Wiener index and Margalef index of shrub layer plants is:80-100%<0-20%<20-40%<60-80%<40-60%successively.(5) Total biomass with shrub layer biomass and shrub layer diversity index with richness index has significant positive correlation, partial reached extremely significant positive correlation. Shrub layer biomass has significant negative correlation with herb layer biomass. Herb layer biomass is significantly positive correlation with plant diversity and richness. In different proportions of mixed forests, shrub layer biomass of understory biomass proportion is higher, the herb layer only accounts for less, with the increase of mix ratio, undergrowth biomass showed a trend of decrease after increase. In different proportion of forest, shrub layer biomass take up of the total biomass of the understory order as:60-80%<80-100%<0-20%<20-40%<40-60%, with80-100%and60-80%of the very significant (P<0.01) lower than other three kinds of proportion.3. Underground(6) The average fine root (d<10mm) biomas of Masson pine mixed is1.693t·hm-2.With the changing of mixed ratio, fine root biomass changes unceasingly. The order of fine root biomass is60-80%<80-100%<0-20%<20-40%<40-60%. The ratio of fine root biomass with total root biomass is in the order:40-60%>20-40%>0-20%>80-100%>60-80%. The highest fine root ratio is in the stand with Masson pine40-60%. Fine root has the function of improve forest soil structure, increasing soil organic matter content, improves the community species richness, also increased the fine root biomass.(7) Soil bulk density is negatively correlated with total biomass, shrub layer biomass of undergrowth and herb layer biomass, soil porosity were positively correlated with them, which places in total biomass has significant negative correlation with soil bulk density and the significant positive correlation with soil porosity. Bulk density has a weak negative effect with the shrub layer’s and herb layer’s biomass; moisture content has certain positive effect with the shrub layer biomass, but did not reach significant level. The index, which content Margalef and Shannon, of understory shrub layer and herb layer showed different degrees of positive correlation with soil water content, pH, organic matter, total nitrogen, total phosphorus, total potassium and available phosphorus and available potassium, but none of them reach significant level. Margalef index and Shannon Wiener index of shrub layer showed a hegher negative correlation with soil bulk density, at0.456and0.432respectively.(8) The fine root biomass is extremely significant positive correlation (P<0.01) with porosity, organic materior. Total phosphorus and available phosphorus are significantly positive correlation (P<0.05) with water content in the0-10cm soil layer. Specific root length is significantly negative correlation (P<0.05) with soil total potassium and total nitrogen. The density of fine root is significantly positively related to density and soil porosity (P<0.05). In10-20cm soil layer, the fine root biomass is very significant positive correlation (P<0.01) with porosity, moisture content, organic matter and total phosphorus, and is significantly positive correlation (P<0.05) with available k. Specific root length was significantly negative correlated (P<0.05) with available potassium and total potassium. In20-30cm soil layer, the fine root biomass is very significant positive correlation (P<0.01) with porosity, water content, available potassium and organic matter are significantly positively related (P<0.05) to total potassium. Root length negatively correlated with total phosphorus. And the root density is significantly positive correlation (P<0.05) with total potassium.4. Forest colosystem(9) The biomass in dirrefent organ difference. The distribution of biomass in the tree is the trunk>root> branch>skin>leaf. Standard of Masson pine wood maximum per plant, and trunk biomass above ground were114.69kg,98.48kg,77.83kg, have appeared in the Masson pine mixed proportion of40-60%of the forest; Minimum value in0-20%mixed in the proportion of forest, respectively is102.8kg,86.01kg,63.57kg. The relationship between biomass of vegetative organs and diameter at breast height and tree height present positive correlation is same as under the tree with diameter at breast height and tree height increases. Masson pine root biomass per plant biomass accounted for about15%, is each organ biomass accounted for the proportion of the total plant biomass change in the smallest. As for Platycarya strobilacea, the relationship between biomass and diameter at breast height and tree height is positively correlated. And the maximum biomass above ground is82.56kg per plant, and appeared in the mixed ratio of20-40%of the forest. The minimum value is65.21kg, and appeared in the mixed ratio of60-80%of the forest. The proportion of trunk biomass is the largest too, followed by the branch and stem.(10) The mixwood with different proportion of Masson pine has different capacity of carbon. Gradient of forest carbon is40-60%>60-80%>0-20%>20-40%>80-100%. The maximum of the litter and coarse wood carbon reserves is2.15t.hm-2, and appeared in the mixed ratio of40-60%of the forest, it is far higher than many other proportion of mixed forest. The mixed proportion of forest litter and coarse wood carbon carbon capacity is far greater than the shrub layer, thus it can be seen, and litter and coarse wood is an important part of carbon sinks. Experimental shows that with the increase of the mixed proportion the0-30cm soil carbon reserves in the study area as follows:40-60%>60-80%>20-40%>80-100%>0-20%.更多还原