Soil nematode communities and their functions are simultaneously influenced by abiotic factors such as temperature and soil moisture. However, the complex interaction effects of these factors have not been clearly demonstrated, limiting our understanding of soil biodiversity and functions under different climate scenarios. Here, we conducted a short-term microcosm experiment, implementing three temperature treatments (20 °C, 25 °C, and 30 °C) combined with two soil moisture treatments (50% and 80% water-holding capacity). We comprehensively assessed the changes in abundance, diversity, composition, and functions (carbon footprints) of soil nematode communities under these different treatments. Our findings revealed that temperature and moisture did not have significant effects on the richness or Shannon diversity of nematodes, while they did have significant impacts on other properties. We found that the interaction effect between temperature and moisture had a greater influence on total abundance compared to their independent effects. Moisture emerged as the primary driver of nematode community composition, followed by the interaction term, while temperature exhibited the least influence. Contrary to expectations, increasing temperature did not cause a shift in the community towards small-bodied genera when considering intraspecific variability in body mass. However, elevating moisture level led to an increase in community-weighted mean body mass, irrespective of intraspecific variability. Consequently, the body-mass-related footprints varied among treatments when considering intraspecific variability, with the dominant influence arising from the interaction effect. Overall, our study highlights the dominant interaction effect of temperature and soil moisture on multiple ecological properties of nematode communities. Additionally, we underscore the importance of incorporating intraspecific trait variability when assessing the responses and functions of nematodes under distinct environmental conditions.

土壤线虫群落及其功能同时受到温度和土壤湿度等非生物因素的影响。然而，这些因素的复杂相互作用效应尚未得到明确证明，限制了我们对不同气候情景下土壤生物多样性和功能的理解。在这里，我们进行了短期微观实验，实施三种温度处理（20°C、25°C和30°C）结合两种土壤湿度处理（50%和80%持水能力）。我们综合评估了不同处理下土壤线虫群落的丰度、多样性、组成和功能（碳足迹）的变化。我们的研究结果表明，温度和湿度对线虫的丰富度或香农多样性没有显着影响，虽然它们确实对其他财产产生了重大影响。我们发现，与独立影响相比，温度和湿度之间的相互作用对总丰度的影响更大。水分成为线虫群落组成的主要驱动因素，其次是相互作用项，而温度的影响最小。与预期相反，考虑到种内体重的变异性，温度升高并没有导致群落向小型属的转变。然而，无论种内变异如何，湿度水平的升高都会导致群落加权平均体重的增加。因此，当考虑种内变异时，与体重相关的足迹在不同处理之间有所不同，其中主要影响来自相互作用效应。总的来说，我们的研究强调了温度和土壤湿度对线虫群落多种生态特性的主导相互作用影响。此外，我们强调在评估线虫在不同环境条件下的反应和功能时纳入种内性状变异的重要性。