UR Gestion Durable des Sols, Pôle de Recherche Environnement et Développement Durable, UFR Sciences de la Nature, Université Nangui Abrogoua, 02 BP 801, Abidjan 02, Cote d'Ivoire.
UR Gestion Durable des Sols, Pôle de Recherche Environnement et Développement Durable, UFR Sciences et Gestion de l'Environnement, Université Nangui Abrogoua, 02 BP 801, Cote d'Ivoire.
J Environ Manage. 2021 Apr 1;283:112002. doi: 10.1016/j.jenvman.2021.112002. Epub 2021 Jan 27.
Conversion of natural forest to anthropogenic land use systems (LUS) often leads to considerable loss of carbon, however, proper management of these LUS may reverse the trend. A study was conducted in a semi-deciduous forest zone of Côte d'Ivoire to assess soil microbial functioning and soil organic carbon (SOC) stocks in varying tree stands, and to determine whether complex tree stands can mimic the natural forest in terms of these soil attributes. Tree plantations studied were monocultures of teak (Tectona grandis) and full-sun cocoa (Theobroma cacao L.), and a mixture of four tree species (MTS) with Tectona grandis, Gmelina arborea, Terminalia ivoriensis and Terminalia superba. An adjacent natural forest was considered as the reference. Each of these LUS had five replicate stands where soil (0-10 cm depth) samples were taken for physico-chemical parameters and microbial biomass-C (MBC), microbial activities, MBC/SOC ratio and metabolic quotient (qCO). SOC and total N stocks were also calculated. The C mineralization rate (mg C-CO kg) and mineral N concentration (mg kg) drastically declined in the monocultures of cocoa (154.9 ± 29.3 and 49.8 ± 9.8, respectively) and teak (179.6 ± 27.1 and 54.1 ± 7.3) compared to the natural forest (258.4 ± 21.9 and 108.7 ± 12). However, values in MTS (194.7 ± 24.6 and 105.4 ± 7.4) were not significantly different from those in the natural forest. Similarly, SOC stocks in MTS (28.8 ± 1.9 Mg ha) were not significantly different from those recorded in the natural forest (32.9 ± 1.7 Mg ha) whereas teak (25.4 ± 1.7 Mg ha) and cocoa (23.1 ± 3.4 Mg ha) exhibited significantly lower values. Despite the acidic soil and recalcitrant litter conditions, increased MBC/SOC ratio and decreased qCO were recorded in the monocrops, suggesting a probable increase in the fungi/bacteria ratio. The complex MTS stand was found to mimic the natural forest in terms of soil microbial activity and organic status, due to the provision of a diversity of litter quality, which may serve as a basis for developing a climate smart timber system in West and Central Africa.
将天然林转换为人为土地利用系统 (LUS) 通常会导致大量碳的损失，但是，对这些 LUS 的适当管理可能会扭转这一趋势。在科特迪瓦的一个半落叶林区进行了一项研究，以评估不同林分中的土壤微生物功能和土壤有机碳 (SOC) 储量，并确定复杂的林分是否可以在这些土壤属性方面模拟天然林。研究的人工林种植是柚木 (Tectona grandis) 和全日照可可 (Theobroma cacao L.) 的单一栽培，以及四种树种的混合物 (MTS)，其中包括柚木、紫薇、非洲鹅掌楸和非洲白木。相邻的天然林被视为参照。这些 LUS 中的每一个都有五个重复的林分，在这些林分中采集土壤（0-10cm 深度）样本，以获取物理化学参数和微生物生物量碳 (MBC)、微生物活性、MBC/SOC 比和代谢商 (qCO)。还计算了 SOC 和总氮储量。可可（154.9±29.3 和 49.8±9.8）和柚木（179.6±27.1 和 54.1±7.3）的单一栽培中，C 矿化率（mg C-CO kg）和矿化氮浓度（mg kg）与天然林（258.4±21.9 和 108.7±12）相比急剧下降。然而，MTS（194.7±24.6 和 105.4±7.4）中的值与天然林中的值没有显著差异。同样，MTS（28.8±1.9 Mg ha）中的 SOC 储量与天然林（28.8±1.9 Mg ha）中的 SOC 储量没有显著差异，而柚木（25.4±1.7 Mg ha）和可可（23.1±3.4 Mg ha）的 SOC 储量明显较低。尽管土壤呈酸性且凋落物较难分解，但在单一栽培中记录到较高的 MBC/SOC 比和较低的 qCO，这表明真菌/细菌比值可能增加。复杂的 MTS 林分在土壤微生物活性和有机状态方面被发现可以模拟天然林，这是因为提供了多种不同质量的凋落物，这可能为在西非和中非建立智能气候木材系统提供基础。
