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The spatial heterogeneity of soil limiting resources is one of the most important factors maintaining biodiversity and ecosystem functions. There is a general concern that herbivore grazing plays a central role in modifying soil resources heterogeneity. However, most studies have examined how large herbivores as a group affect soil heterogeneity. There is limited knowledge about how assemblages of different herbivore species may influence soil heterogeneity, and whether the herbivore assemblage effects might vary with grassland types. Here we conducted a 4‐year grazing experiment to examine the effects of different herbivore assemblages (no grazing; cattle grazing; sheep grazing; and mixed grazing of cattle and sheep) on the spatial heterogeneity of soil N availability across three types of grasslands (meadow steppe, typical steppe and desert steppe) in eastern Eurasian steppe. The results showed that all the herbivore grazing increased the heterogeneity of soil N availability in the three grasslands with different precipitation (only cattle grazing and mixed grazing of cattle and sheep in meadow steppe did not reach a statistically significant level). The consistently increased heterogeneity of soil N availability was primarily due to the effect of animal excreta addition, which weakened in drier grasslands, likely because of the slower excreta decomposition. Moreover, sheep excreta contributed more to soil N heterogeneity than that of other herbivore assemblages, and the effect was statistically significant in meadow steppe and typical steppe with relative high precipitation. Synthesis and applications. Our study indicates that sheep could have larger potential to maintain and enhance grassland heterogeneity than cattle especially in grassland ecosystems with high precipitation. We therefore suggest that managing above‐ground herbivore species is important for conserving and promoting grassland soil heterogeneity, and that the management should also take into account local environmental conditions such as precipitation.

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1. Nitrogen (N) resorption is a strategy for plant N conservation through which plants withdraw N from senescing leaves prior to litterfall and its underlying mechanisms are important for better understanding of N cycling. However, most current studies focused on the impacts of soil and leaf nutrients on leaf N resorption efficiency (NRE), and plant physiological regulation that is species dependent is still unclear.2. Here, we conducted a field experiment to investigate the variations of leaf NRE along an altitudinal gradient in a temperate forest of Northeastern China. 3. Results showed that leaf NRE of Quercus mongolica and Fraxinus mandshurica increased with altitude, while leaf NRE of Tilia amurensis, Acer mono and Acer pseudosieboldianum exhibited an opposite trend, although the relationships were not significant for F. mandshurica and A. mono. The inconsistent responses of leaf NRE of different species to increasing altitude were primarily due to the effect of leaf Glutamate dehydrogenase (GDH), an enzyme responsible for N translocation. Leaf GDH activity in senescing leaves explained the variation of NRE more than soil and climate factors did, suggesting that different plant species had different physiological regulation strategies for their N conservation under similar environment. 4. Synthesis. Our study highlights the role of leaf enzyme as a pivotal regulator of leaf NRE and helps us better understand and predict N cycling under climate change in forest ecosystems.