| 摘要: |
| 【 目的】研究不同岩溶裂隙下湿地松幼苗生长状况对降雨间隔时长的响应，为石漠化地区湿地松幼苗 生长提供一定理论依据。【 方法】以2年生湿地松幼苗为研究对象，采用双因素区组试验，因素1为不同降雨间隔时长，即降雨间隔时长3 d（I3d，减少时长）、6 d（I6d，自然时长）和9 d（I9d，延长时长），因素2为不同岩溶小生境，即无石全土（S0）、少石多土（S1/4）和半石半土（S1/2），在试验结束时测量幼苗生长指标、生物量及营养元素含量。【 结果】①湿地松 幼苗生长量在同一降雨间隔时长下随岩溶裂隙的加深均呈先增加后减少的趋势，在 S1/4岩溶生境下达到最大，其中地径最大为12.01 cm，苗高最高为54.28 cm，针叶长最长为16.13 cm；在同一岩溶生境下，随降雨间隔时长的延长表现 为逐渐下降趋势。②湿地松幼苗各器官生物量在I3d和I6d降雨间隔条件下随岩溶裂隙的加深表现出先上升后下降的规律，在I9d下则均表现为逐渐下降趋势；湿地松幼苗茎、叶、地上生物量在同一岩溶生境下随降雨间隔时长的延长均表 现为逐渐下降趋势（除S0处理下的地径、S1/4处理下的茎生物量外），根生物量、总生物量随降雨间隔时长的延长表现出先增加后减少的趋势。I3d和I6d下各器官生物量分配比均表现为叶>茎>根，而I9d下表现为根>茎>叶；根冠比在I9dS1/2下最大，为0.61。③湿地松幼苗各器官矿质营养元素含量在I3d和I6d下随岩溶裂隙的加深呈先上升后下降的规律，在I9d下则均表现为逐渐下降趋势，且各器官K+、Ca2+、Na+、Mg2+含量均表现为根>叶>茎，各器官矿质营养元素含量均表现为Ca2+>Mg2+>K+>Na+，而各器官K+、Ca2+、Na+、Mg2+在同一岩溶生境下随降雨间隔时长的延长呈逐渐下降趋势（除S0处理下的Ca2+外），各器官K+/Na+在同一岩溶生境下表现为逐渐上升趋势（除S1/4生境中的根K+/Na+和S0生境中的叶K+/Na+外），且叶K+/Na+在所有处理中最大（5.52）。④主成分分析得出累计方差贡献率为72.2%，能代表绝大多数信息。⑤湿地松幼苗生长及矿质营养元素含量之间均呈极显著正相关（P<0. 01）。⑥模糊 隶属分析表明，湿地松幼苗生长状况在不同处理下表现为I3dS1/4>I3dS0>I6dS1/4>I3dS1/2>I6dS0>I9dS0>I6dS1/2>I9dS1/4>I9dS1/2。【 结论】延长降雨间隔时长对湿地松幼苗生长有抑制作用，I3d和I6d下增加岩溶裂隙能在一定程度上促进湿地 松幼苗的生长发育；I3dS1/4处理下湿地松幼苗生长最好，其次是I3dS0和I6dS1/4处理。 |
| 关键词: 湿地松幼苗 岩溶生境 降雨间隔时长 生物量 矿质营养元素 |
| DOI：10. 13207/j. jnwafu. 2026. 08. 006 |
| 分类号: |
| 基金项目:云南省重点研发专项项目（202102AE090132） |
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| Response of Pinus elliottii seedlings’ growth to simulated rainfall in Karst habitats |
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SHI Shunrou, ZHENG Shaojie, CHEN Yu, WANG Lin, DONG Qiong
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College of Forestry，Southwest Forestry University，Kunming，Yunnan 650224，China
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| Abstract: |
| 【 Objective】This study aimed to investigate the response of Pinus elliottii seedling growth to rainfall interval duration under different Karst fissures，thereby providing a certain theoretical basis for the growth of P.elliottii seedlings in rocky desertification areas.【Method】A two-factor block experiment was conducted using 2-year-old P.elliottii seedlings. Factor 1 consisted of different rainfall intervals：a shortened interval of 3 days （I3d），a natural interval of 6 days （I6d），and an extended interval of 9 days （I9d）.Factor 2 comprised different Karst microhabitats：soil without stones（S0），soil with a few stones（S1/4），and half soil and half stones （S1/2）.At the end of the experiment，the growth indicators，biomass，and nutrient element contents of the seed-lings were measured.【Result】①The growth parameters of P.elliottii seedlings exhibited an initial increase fol-lowed by a decrease as the Karst fissures deepened under the same rainfall interval duration，reaching its maxi?mum in the S1/4 Karst habitat. The maximum ground diameter，seedling height，and needle length were 12.01 cm，54.28 cm，and 16.13 cm，respectively. Under the same Karst habitat，the growth parameters showed a gradual decline with the extension of the rainfall interval duration. ②Under I3d and I6d，the biomass of various organs of P.elliottii seedlings demonstrated an initial increase followed by a decrease with the deepening of Karst fissures，while a gradual decline was observed under I9d. Under the same Karst habitat，stem，leaf，and aboveg-round biomass exhibited a gradual decline with the extension of the rainfall interval duration （except for basal diameter under S0 treatment and stem biomass under S1/4 treatment）.In contrast，root biomass and total biomass showed an initial increase followed by a decrease. The biomass allocation ratio of various organs under I3d and I6d ranked leaf >stem>root，but shifted to root>stem>leaf under the I9d. The root-to-shoot ratio was highest （0.61） under the I9dS1/2 treatment. ③Under I3d and I6d，the mineral nutrient content in various organs of P.elliottii seedlings exhibited an initial increase followed by a decrease with the deepening of Karst fissures，while a gradual decline was observed under a I9d. The content of K+，Ca2+，Na+，and Mg2+ in various organs ranked root>leaf>stem，with the order of overall mineral nutrient content being Ca2+>Mg2+>K+>Na+.Under the same Karst habitat，the content of K+，Ca2+，Na+，and Mg2+ in various organs showed a gradual decline with the extension of the rainfall interval duration （except for Ca2+ under S0 treatment）. The K+/Na+ ratio in all organs exhibited a gradual increase under the same Karst habitat （except for the root K+/Na+ in the S1/4 habitat and leaf K+/Na+ in the S0 habitat），with the maximum leaf K+/Na+ ratio of 5.52 observed across all treatments. ④Principal compo-nent analysis revealed a cumulative variance contribution rate of 72.2%，accounting for the majority of the infor-mation. ⑤The growth of P.elliottii seedlings and the content of mineral nutrients exhibited a highly significant positive correlation （P<0.01）.⑥ Fuzzy membership analysis ranked the growth performance of P.elliottii seedlings under different treatments as follows：I3dS1/4>I3dS0>I6dS1/4>I3dS1/2>I6dS0>I9dS0>I6dS1/2>I9dS1/4>I9dS1/2.【Conclusion】Prolonging the rainfall interval duration exerted an inhibitory effect on the growth of P.elliottii seedlings. Under I3d and I6d treatments，a moderate increase in Karst fissure depth promoted the growth and development of P.elliottii seedlings. Consequently，seedlings exhibited optimal growth under the I3dS1/4 treat-ment，followed by the I3dS0 and I6dS1/4 treatments. |
| Key words: Pinus elliottii seedings Karst habitat duration of rainfall interval biomass mineral nutrient element |
