Abstract Green spaces in urban parks are an essential part of urban planning, not only meeting the environmental demands of urban dwellers but also absorbing greenhouse gases generated in urban regions. Mineralization of soil organic carbon (SOC) is one of the most important processes of C cycling, and links C sequestration and emission. However, few studies have been focused on SOC mineralization in urban parks, especially in scenarios involving rising temperature. Here, soils from different ages of deciduous forest (DT), evergreen forest (ET) and lawn (LN) were collected from the urban parks of Chengdu megacity. A soil incubation study (35 days) was conducted to examine SOC mineralization in three temperature regimes (15, 25, and 35 ℃), three vegetation types (DT, ET, and LN) and three vegetation ages (5, 10, and 15yr), making 27 treatments in total. Results demonstrate that increases in temperature stimulated the daily SOC mineralization rate, cumulative SOC mineralization, and mineralization intensity in the soils from urban green spaces, especially in soils under the 5-year-old plantings. Furthermore, results from principal component analysis (PCA) showed that the soil labile organic carbon (LOC) fraction, especially readily oxidizable carbon (ROC), soil enzyme activity and soil pH are the major factors influencing SOC mineralization. During the incubation, the average temperature sensitivity (Q10) of the SOC mineralization rate at 25−35 °C was higher than at 15−25 °C (P ET > DT, while the Q10 of the SOC mineralization rate was ranked DT > ET > LN with increasing temperatures. Moreover, the older vegetation showed lower SOC mineralization rates and higher Q10 values. These findings imply that SOC stored in the soils under grass and young plantations are less susceptible to climate warming, although the mineralization rates are higher. By contrast, SOC in soils under trees is more susceptible to climate warming, but the mineralization rates are lower. Overall, the temperature change is more important for the SOC mineralization in forest soils and older plantation soils in urban green spaces.

中文翻译：

---

温度诱导城市公园绿地土壤有机碳矿化，成都，西南：种植年限和植被类型的影响

摘要 城市公园绿地是城市规划的重要组成部分，不仅可以满足城市居民的环境需求，还可以吸收城市区域产生的温室气体。土壤有机碳（SOC）矿化是碳循环最重要的过程之一，将碳封存和排放联系起来。然而，很少有研究关注城市公园中的 SOC 矿化，尤其是在温度升高的情况下。在这里，从成都特大城市的城市公园收集了落叶林（DT）、常绿林（ET）和草坪（LN）不同年龄的土壤。进行了土壤孵化研究（35 天），以检查三种温度条件（15、25 和 35 ℃）、三种植被类型（DT、ET 和 LN）和三种植被年龄（5、10 和 15 年）下的 SOC 矿化), 共27个疗程。结果表明，温度升高刺激了城市绿地土壤中的每日 SOC 矿化率、累积 SOC 矿化率和矿化强度，尤其是在 5 年种植以下的土壤中。此外，主成分分析 (PCA) 的结果表明，土壤不稳定有机碳 (LOC) 部分，尤其是易氧化碳 (ROC)、土壤酶活性和土壤 pH 值是影响 SOC 矿化的主要因素。在孵化过程中，SOC矿化率在25-35℃的平均温度敏感性（Q10）高于15-25℃（P ET > DT，而SOC矿化率的Q10排序为DT > ET > LN 随着温度的升高。此外，较老的植被显示出较低的 SOC 矿化率和较高的 Q10 值。这些发现意味着，尽管矿化率更高，但储存在草地和年轻种植园下土壤中的 SOC 不太容易受到气候变暖的影响。相比之下，树下土壤中的 SOC 更容易受到气候变暖的影响，但矿化率较低。总体而言，温度变化对于城市绿地中森林土壤和老种植园土壤中的 SOC 矿化更为重要。