Agroforestry practices that include trees on grazing lands could enhance atmospheric CO₂ sequestration and storage. However, carbon sequestration rates and storage capacity of intensively grazed agroforestry systems vary due to the diversity in species composition, stand structure, system age, and management practices. The objective of this study was to evaluate carbon stocks and accrual rates in Leucaena leucocephala + Cynadon plectostachyus, and Brachiaria decumbens grass silvopastoral systems and compare them with conventional open grazing lands. The study was carried out in Chiapas in southern Mexico, one of the hotspots of deforestation driven by the expansion of livestock farming. We measured above- and belowground carbon stocks in 18 silvopasture (SP) plots, with the plantation age ranging from 2 to 10 years. Nine plots of adjacent conventional full-sun grasslands (open pasturelands) grazed rotationally were sampled for comparison. The average tree biomass stock in SP was 5.5 ± 1.9 Mg C ha⁻¹ and differed with SP age. Mean annual biomass accrual rates ranged from 0.25 to 2.57 Mg C ha⁻¹ year⁻¹, indicating that SP systems are CO₂ sinks, excluding other sources of GHG such as methane emissions from enteric fermentation. The average soil organic carbon (SOC) sequestration rate of SP was 0.143 ± 0.043 Mg C ha⁻¹ year⁻¹ to 50 cm depth. The SOC sequestration rates correlated positively with SP age at the beginning and decreased after about 8 years. The results suggested that the age and lifespan of trees play a significant role in aboveground C sequestration through the Leucaena leucocephala SP, while SOC storage varied with soil properties. Further research on the relative response of active and stable SOC fractions along with soil CO₂ fluxes could explain the results on the SOC storage potential of these agroforestry systems.

包括在牧场上种植树木在内的农林业实践可以增强大气中的 CO ₂封存和储存。然而，由于物种组成、林分结构、系统年龄和管理实践的多样性，集约化放牧农林复合系统的固碳率和碳储存能力也有所不同。本研究的目的是评估银合欢 +  Cynadon plectostachyus和臂形草林牧系统的碳储量和累积率，并将其与传统的开放牧场进行比较。这项研究是在墨西哥南部的恰帕斯州进行的，这里是畜牧业扩张导致森林砍伐的热点地区之一。我们测量了 18 个森林牧场 (SP) 地块的地上和地下碳储量，种植园年龄从 2 年到 10 年不等。对相邻的轮流放牧的常规全日照草原（开阔牧场）进行了九个样地的抽样比较。SP 中的平均树木生物量储量为 5.5 ± 1.9 Mg C ha ^-1，并且随 SP 年龄的不同而不同。平均年生物量增长率范围为0.25至2.57 Mg C ha ^{-1year -1}，表明SP系统是CO ₂汇，不包括其他温室 气体来源，例如肠道发酵产生的甲烷排放。SP的平均土壤有机碳（SOC）固存率为0.143±0.043 Mg C ha ^-1 年^-1至50 cm深度。SOC 封存率在开始时与 SP 年龄呈正相关，并在约 8 年后下降。结果表明，树木的年龄和寿命在银合欢SP 的地上固碳过程中发挥着重要作用，而 SOC 储存量随土壤性质的不同而变化。对活性和稳定 SOC 部分与土壤 CO ₂通量的相对响应的进一步研究可以解释这些农林业系统的 SOC 存储潜力的结果。