Key message

Fine-root biomass relates to environmental variables differently along a rainfall gradient in Ghana.

Abstract

Understanding changes in root dynamics in response to environmental factors is crucial for projections of climate change, yet information on controls of root dynamics is limited in the tropics. This study quantified fine-root dynamics along a rainfall gradient in Ghana, ranging from dry to wet evergreen forests. Fine-root biomass and necromass were estimated by the sequential coring method for a year and analyzed in relation to measured environmental factors (rainfall, soil moisture content, air temperature and soil temperature). Overall, fine-root biomass increased along the gradient with the highest estimate found in the wet forest site. Mean annual fine root production ranged from 276.60 to 348.95 gm⁻² year⁻¹ across the different forest types. Fine-root turnover rates ranged from 2.3 to 3.1 year⁻¹, and roots tended to turn over faster in the dry than in the moist and wet forest sites. There was a non-linear but significant relationship between fine-root biomass and soil moisture content in the wet forest. None of the environmental factors related to fine-root biomass in the moist forest. However, there was a significant non-linear relationship between rainfall and fine-root biomass in the dry forest site. These results suggest that environmental factors influence fine-root biomass differently across the three forest types. Therefore, future studies should focus on a comprehensive measurement of environmental controls to deepen our understanding of fine root dynamics.

中文翻译：

---

加纳沿降雨梯度的细根动力学模式和控制

关键信息

细根生物量在加纳的降雨梯度上对环境变量的影响不同。

抽象

理解根系动态响应环境因素的变化对于预测气候变化至关重要，但是在热带地区，有关根系动态控制的信息有限。这项研究对加纳从干旱到常绿森林的降雨梯度上的细根动态进行了量化。细根生物量和坏死通过连续取心法估算了一年，并与测得的环境因素（降雨，土壤水分，空气温度和土壤温度）进行了分析。总体而言，细根生物量沿梯度增加，在湿林地带发现的最高估计值。年平均细根产量范围为276.60至348.95 gm - ² 年^-1跨越不同的森林类型。细根周转率在2.3到3.1年^-1之间，干旱和湿润林地的根部翻倒速度更快。在湿林中，细根生物量与土壤水分之间存在非线性但显着的关系。没有任何环境因素与潮湿森林中的细根生物质有关。然而，在干旱的森林地带，降雨与细根生物量之间存在显着的非线性关系。这些结果表明，环境因素在三种森林类型中对细根生物量的影响不同。因此，未来的研究应着重于对环境控制的综合测量，以加深我们对优良根系动态的理解。