Environmental Technology Division, CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT), Palampur, Himachal Pradesh 176 061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201 002, India; Centre for High Altitude Biology (CeHAB), Research Centre of CSIR-IHBT, Ribling, P.O. Tandi, District Lahaul and Spiti, Himachal Pradesh 175132, India.
Environmental Technology Division, CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT), Palampur, Himachal Pradesh 176 061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201 002, India; Centre for High Altitude Biology (CeHAB), Research Centre of CSIR-IHBT, Ribling, P.O. Tandi, District Lahaul and Spiti, Himachal Pradesh 175132, India.
Sci Total Environ. 2024 Jan 10;907:167906. doi: 10.1016/j.scitotenv.2023.167906. Epub 2023 Oct 17.
Snow-melt is one of the important factors limiting growth and survival of alpine plants. Changes in snow-melt timing have profound effects on eco-physiological characteristics of alpine plant species through alterations in growing season length. Here, we conducted a field experiment and studied species response to experimentally induced early snow-melting (ES) (natural vs. early) at an alpine site (Rohtang) in the western Himalaya region. Eco-physiological response of eight snow-bed restricted alpine plant species from different elevations (lower: 3850 m and upper: 4150 m amsl) and belonging to contrasting resource acquisition strategies (conservative and acquisitive) were studied after 2-years (2019 & 2020) of initiating ES field experiment. We estimated the functional traits related to leaf economic spectrum and physiological performance and assessed their pattern of phenotypic plasticity. Analysis by linear mixed effect model showed that both the 'conservative' and 'acquisitive' species had responded to ES with significant effects on species specific leaf area, leaf dry matter content, leaf thickness, leaf water content and sugar content. Our results also revealed that ES treatment induced significant increase in leaf C/N ratio (10.57 % to 13.65 %) and protein content (15.85 % to 20.76 %) at both the elevations, irrespective of species groups. The phenotypic plasticity was found to be low and was essentially species-specific. However, for leaf protein content, the upper elevation species exhibited a higher phenotypic plasticity (0.43 ± 0.18) than the lower elevation species (0.31 ± 0.21). Interestingly, we found that irrespective of species unique functional strategy, species adapt to perform more conservative at lower elevation and more acquisitive at upper elevation, in response to ES. We conclude that plants occurring at contrasting elevations respond differentially to ES. However, species showed capacity for short-term acclimation to future environmental conditions, but may be vulnerable, if their niche is occupied by new species with greater phenotypic plasticity and a superior competitive ability.
融雪是限制高山植物生长和生存的重要因素之一。融雪时间的变化通过改变生长季节的长度，对高山植物物种的生态生理特征产生深远的影响。在这里，我们在喜马拉雅山西部的罗塘（Rohtang）高原地区进行了一项野外实验，研究了物种对实验诱导的早期融雪（ES）（自然与早期）的响应。我们研究了来自不同海拔（低海拔：3850 米，高海拔：4150 米）、具有不同资源获取策略（保守和进取）的 8 种雪床限制的高山植物物种在启动 ES 野外实验 2 年后（2019 年和 2020 年）对生态生理的响应。我们估计了与叶片经济谱和生理性能相关的功能特征，并评估了它们表型可塑性的模式。线性混合效应模型分析表明，“保守”和“进取”物种都对 ES 做出了响应，对物种特定叶面积、叶干物质含量、叶厚度、叶含水量和糖含量都有显著影响。我们的研究结果还表明，ES 处理在两个海拔高度上都诱导了叶片 C/N 比（10.57%到 13.65%）和蛋白质含量（15.85%到 20.76%）的显著增加，而与物种群体无关。表型可塑性较低，基本上是物种特异性的。然而，对于叶片蛋白质含量，高海拔物种表现出比低海拔物种更高的表型可塑性（0.43±0.18 比 0.31±0.21）。有趣的是，我们发现，无论物种独特的功能策略如何，物种都倾向于在较低海拔处表现出更保守的适应，而在较高海拔处表现出更进取的适应，以应对 ES。我们得出结论，在不同海拔高度的植物对 ES 的反应存在差异。然而，植物表现出对未来环境条件进行短期适应的能力，但如果它们的生态位被具有更大表型可塑性和更高竞争能力的新物种占据，它们可能会很脆弱。
