林分密度对油松人工林生长特征及林下植被多样性的影响

Effects of stand density on the growth characteristics of Pinus tabuliformis plantation and understory vegetation diversity

摘要

【目的】研究不同密度油松人工林的生长特征及其对林下植被多样性的影响，为晋西黄土区油松林的可持续经营提供科学依据。【方法】以 11 种林分密度的油松人工林（林龄为 30 年）为研究对象，通过野外调查和室内试验，测定油松林生长特征、生物量和植被多样性，利用单因素方差分析、Pearson 相关分析和结构方程模型分析林分密度对油松生长特性及林下植被多样性的影响。【结果】（1）油松的平均树高均随密度增大呈波动变化，平均胸径呈递减趋势。（2）高密度林分（≥3 250 株/hm²）促进树干、松果的生物量分配，低密度林分（≤1 750 株/hm²）更利于枝条和叶片的生物量分配；单株生物量随密度增大呈下降趋势，林分总生物量随密度增大呈先增后减的单峰变化，在 1 750 株/hm² 时达到最大值 148.81 t/hm²。（3）林下灌木层 Shannon-Wiener 多样性指数在 1 750 株/hm² 时最大，Margalef 丰富度指数在 1 250 株/hm² 时最大；草本层 Shannon-Wiener 多样性指数和 Margalef 丰富度指数在 1 250 株/hm² 时最大。（4）结构方程模型分析显示，密度通过油松生长特征间接正向调控草本多样性，负向调控灌木多样性。【结论】晋西黄土区油松林通过间伐将密度调控至 1 250 ~ 1 750 株/hm² 区间，可实现林分生产力与林下生物多样性的协同提升。

Abstract

[Objective] This study aimed to investigate the growth characteristics of Pinus tabuliformis plantations at different densities and their impacts on understory vegetation diversity, providing a scientific basis for sustainable management of P. tabuliformis forests in the loess region of western Shanxi Province of northern China. [Method] Eleven plantation densities of P. tabuliformis (forest age is 30 years) were selected as study objects. Field surveys and laboratory experiments were conducted to measure growth traits, biomass, and vegetation diversity. Univariate analysis of variance (ANOVA) and structural equation modeling (SEM) were employed to analyze the effects of stand density on growth traits of P. tabuliformis and understory vegetation diversity. [Results] The findings revealed: (1) The average tree height of P. tabuliformis fluctuates with increasing stand density, while the average diameter at breast height (DBH) exhibits a decreasing trend. (2) High-density stands promoted biomass allocation to stems, cones, whereas low-density stands favored branches and leaves. As stand density increases, the individual biomass of P. tabuliformis shows a decreasing trend, whereas the total stand biomass reaches its maximum value of 148.81 t/hm² at a density of 1 750 trees/ha. (3) The Shannon-Wiener diversity index of the understory shrub layer reaches its maximum at a density of 1 750 trees/ha, while the Margalef richness index peaks at 1 250 trees/ha. For the herbaceous layer, both the Shannon-Wiener diversity index and the Margalef richness index attain their maximum values at a density of 1 250 trees/ha. (4) SEM analysis indicated that density indirectly enhanced herbaceous diversity by positively influencing P. tabuliformis growth traits and individual tree biomass but inhibited shrub diversity. [Conclusion] By thinning the P. tabuliformis forests in the loess region of western Shanxi to achieve a density within the range of 1 250–1 750 trees/ha, it is possible to achieve a synergistic enhancement of both stand productivity and understory biodiversity.

关键词

油松人工林 / 林分密度 / 生长特征 / 生物量 / 林下植被多样性 / 结构方程模型

Key words

Pinus tabuliformis plantation / stand density / growth traits / biomass / understory vegetation diversity / structural equation modeling

参考文献

[1] 张秀萍. 推进林草生态保护建设, 筑牢生态安全屏障[J].中国林业产业, 2023(8): 46-47.

[2] Zhang X P. Promote the construction of forest and grass ecological protection and build an ecological security barrier[J].China Forestry Industry, 2023(8): 46-47.

[3] 陈长启, 和璐璐, 段劼. 北京油松人工林生长对密度和立地的响应[J].西南林业大学学报 (自然科学), 2024, 44(6): 8-20.

[4] Chen C Q, He L L, Duan J. Growth pattern to density and site condition of Pinus tabuliformis plantation in Beijing[J].Journal of Southwest Forestry University (Natural Sciences), 2024, 44(6): 8-20.

[5] 杨盛扬. 马尾松人工林密度效应规律研究 [D].长沙: 中南林业科技大学, 2022.

[6] Yang S Y. Study on density effect law of Pinus massoniana plantation[D]. Changsha:Central South University of Forestry & Technology, 2022.

[7] 罗也, 王君, 杨雨春, 等. 东北胡桃楸次生林生长随林龄和林分密度的变化规律[J].北京林业大学学报, 2024, 46(6): 10-19.

[8] Luo Y, Wang J, Yang Y C, et al. Growth patterns of Juglans mandshurica secondary forest with stand age and stand density in Northeast China[J].Journal of Beijing Forestry University, 2024, 46(6): 10-19.

[9] 仲怡铭, 陈徵尼, 王慧慧, 等. 油松人工林林分特征对密度调控的响应[J].森林与环境学报, 2023, 43(6): 606-613.

[10] Zhong Y M, Chen Z N, Wang H H, et al. Responses of stand characteristics of Pinus tabuliformis plantation to density regulation[J].Journal of Forest and Environment, 2023, 43(6): 606-613.

[11] 郭艳杰, 毕华兴, 赵丹阳, 等. 不同密度油松林地土壤水碳分布特征及其耦合关系[J].应用生态学报, 2025, 36(1): 50-58.

[12] Guo Y J, Bi H X, Zhao D Y, et al. Soil water and carbon distribution characteristics and their coupling relationship in Pinus tabuliformis plantations with different densities[J].Chinese Journal of Applied Ecology, 2025, 36(1): 50-58.

[13] Chen S, Wei W, Huang Y. Biophysical controls on canopy transpiration of Pinus tabulaeformis under different soil moisture conditions in the Loess Plateau of China[J].Journal of Hydrology, 2024, 631: 130799.

[14] 韩新生, 许浩, 郭永忠, 等. 六盘山西侧华北落叶松林密度对生长和林分蓄积的影响[J].甘肃农业大学学报, 2023, 58(2): 169-179.

[15] Han X S, Xu H, Guo Y Z, et al. Influence of stand density on growth and stand volume of Larix principis-rupprechtii plantations on the west side of Liupan Mountain[J].Journal of Gansu Agricultural University, 2023, 58(2): 169-179.

[16] 卢德浩, 陈世清, 谢惠燕, 等. 不同密度杉木人工林林分生长和林分结构差异研究[J].西北林学院学报, 2023, 38(6): 162-170.

[17] Lu D H, Chen S Q, Xie H Y, et al. Differences in stand growth and structure of Cunninghamia lanceolata plantations with different densities[J].Journal of Northwest Forestry University, 2023, 38(6): 162-170.

[18] Zhang Y, Liu T, Guo J, et al. Changes in the understory diversity of secondary Pinus tabulaeformis forests are the result of stand density and soil properties[J].Global Ecology and Conservation, 2021, 28: e01628.

[19] Chen Y, Cao Y. Response of tree regeneration and understory plant species diversity to stand density in mature Pinus tabulaeformis plantations in the hilly area of the Loess Plateau, China[J].Ecological Engineering, 2014, 73: 238-245.

[20] 兰道云, 毕华兴, 赵丹阳, 等. 晋西黄土区不同密度油松人工林保育土壤功能评价[J].水土保持学报, 2022, 36(2): 189-196.

[21] Lan D Y, Bi H X, Zhao D Y, et al. Evaluation on soil conservation function of Pinus tabulaeformis plantation with different densities in the loess area of western Shanxi Province[J].Journal of Soil and Water Conservation, 2022, 36(2): 189-196.

[22] Qing S, Yang H, Xu Z, et al. Mid- to long-term influence of gaps on natural regeneration in Pinus tabuliformis plantations on the Loess Plateau[J].Forest Ecology and Management, 2025, 584: 122612.

[23] Wang J, Gao J, Zhang H, et al. Changes in rhizosphere soil fungal communities of Pinus tabuliformis plantations at different development stages on the Loess Plateau[J].International Journal of Molecular Sciences, 2022, 23(12): 6753.

[24] 宋永昌. 植被生态学[M]. 2 版.北京: 高等教育出版社, 2017.

[25] Song Y C. Vegetation ecology[M]. 2nd ed. Beijing: Higher Education Press,2017.

[26] Jagodziński A M, Dyderski M K, Gęsikiewicz K, et al. Effects of stand features on aboveground biomass and biomass conversion and expansion factors based on a Pinus sylvestris L. chronosequence in Western Poland[J].European Journal of Forest Research, 2019, 138(4): 673-683.

[27] 李若楚, 徐剑莹, 李铁华, 等. 不同密度对长周期经营杉木林生长、土壤理化性质和微生物的影响[J].中南林业科技大学学报, 2025, 45(2): 165-174.

[28] Li R C, Xu J Y, Li T H, et al. Effects of different densities on growth, soil physicochemical properties and microorganisms of long-period management Cunninghamia lanceolata forest[J].Journal of Central South University of Forestry & Technology, 2025, 45(2): 165-174.

[29] 尤健健, 张文辉, 邓磊. 油松中龄林间伐的密度效应[J].西北林学院学报, 2015, 30(1): 172-177.

[30] You J J, Zhang W H, Deng L. Intermediate cutting density effects on middle-aged Pinus tabulaeformis plantation[J].Journal of Northwest Forestry University, 2015, 30(1): 172-177.

[31] 韩照日格图, 白玉荣, 王立军, 等. 沙地樟子松林分密度对林木生长的影响研究[J].林业调查规划, 2021, 46(4): 1-6.

[32] Han Z, Bai Y R, Wang L J, et al. Effects of stand density of Pinus sylvestris var. mongolica on forest growth in sandy land[J].Forest Inventory and Planning, 2021, 46(4): 1-6.

[33] 王云霓, 高孝威, 苏雅拉巴雅尔, 等. 林分密度和林龄对华北落叶松人工林生长特征的影响[J].内蒙古林业科技, 2018, 44(3): 12-16.

[34] Wang Y N, Gao X W, Su Y, et al. Effects of different densities and ages on growth of Larix principis- rurechitii plantation in Daqing Mountains of Inner Mongolia[J].Journal of Inner Mongolia Forestry Science and Technology, 2018, 44(3): 12-16.

[35] 李宇婷, 马爱云, 苗铮, 等. 邻域竞争对长白落叶松生物量及其分配的影响[J].北京林业大学学报, 2025, 47(4): 92-102.

[36] Li Y T, Ma A Y, Miao Z, et al. Effects of neighborhood competition on biomass and its allocation of Larix olgensis [J].Journal of Beijing Forestry University, 2025, 47(4): 92-102.

[37] 高青青, 于小萌, 许竹锐, 等. 坡向对冀北山地蒙古栎幼树生长及生物量分配的影响[J].北京林业大学学报, 2023, 45(12): 49-58.

[38] Gao Q Q, Yu X M, Xu Z R, et al. Effects of aspect on growth and biomass allocation of Quercus mongolica saplings in the mountain area of northern Hebei Province, northern China[J].Journal of Beijing Forestry University, 2023, 45(12): 49-58.

[39] Farooq T H, Wu W, Tigabu M, et al. Growth, biomass production and root development of Chinese fir in relation to initial planting density[J].Forests, 2019, 10(3): 236.

[40] Tun T N, Guo J, Fang S, et al. Planting spacing affects canopy structure, biomass production and stem roundness in poplar plantations[J].Scandinavian Journal of Forest Research, 2018, 33(5): 464-474.

[41] 唐鹏, 张建军, 赵炯昌, 等. 晋西黄土区油松人工林空间结构与水文效应的关系[J].生态学杂志, 2025, 44(5): 1417-1426.

[42] Tang P, Zhang J J, Zhao J C, et al. Relationship between spatial structure and hydrological effect of Pinus tabuliformis plantation in the loess region of western Shanxi Province[J].Chinese Journal of Ecology, 2025, 44(5): 1417-1426.

[43] 宋爱云, 董林水, 周金星, 等. 晋西黄土丘陵边缘区油松人工林密度调控与生物量特征[J].西北林学院学报, 2016, 31(4): 7-11,66.

[44] Song A Y, Dong L S, Zhou J X, et al. Suitable density management and biomass characters of Pinus tabulaeformis plantations in the ecotone between bedrock region and loess hill area of west Shanxi Province[J].Journal of Northwest Forestry University, 2016, 31(4): 7-11,66.

[45] 胡亚伟, 施政乐, 刘畅, 等. 晋西黄土区刺槐林密度对林下植物多样性及土壤理化性质的影响[J].生态学杂志, 2023, 42(9): 2072-2080.

[46] Hu Y W, Shi Z L, Liu C, et al. Effects of stand densities on understory vegetation diversity and soil physicochemical properties of Robinia pseudoacacia forest in loess region of western Shanxi Province[J].Chinese Journal of Ecology, 2023, 42(9): 2072-2080.

[47] 李晓燕, 孙建军, 段爱国, 等. 杉木幼龄林生长的良种与初植密度互作效应研究[J].林业科学研究, 2024, 37(6): 62-72.

[48] Li X Y, Sun J J, Duan A G, et al. Interaction effects between improved varieties and planting densities in young Chinese fir plantations[J].Forest Research, 2024, 37(6): 62-72.

[49] 缑倩倩, 刘婧, 王国华, 等. 晋西北丘陵风沙区柠条林下草本植物群落组成和种群生态位变化特征[J].生态学报, 2022, 42(22): 9069-9090.

[50] Gou Q Q, Liu J, Wang G H, et al. Changes of herbaceous plant composition and niche characteristics in different-aged artificial Caragana korshinskii forest in sandy-hilly region of northwest Shanxi Province, China[J].Acta Ecologica Sinica, 2022, 42(22): 9069-9090.

[51] 吴海平, 孙清琳, 张彦君, 等. 不同密度油松人工林群落特征与物种多样性耦合关系[J].西北林学院学报, 2022, 37(5): 1-8.

[52] Wu H P, Sun Q L, Zhang Y J, et al. Coupling relationship between community characteristics and species diversity of Pinus tabuliformis plantations with different densities[J].Journal of Northwest Forestry University, 2022, 37(5): 1-8.

基金资助

国家重点研发计划(2022YFE0104700)