Uncovering the structural properties of ecological networks is a crucial starting point when studying the system's stability in response to various types of perturbations. We analyze pollination and seed disposal networks, which are representative examples of mutualistic networks in ecosystems, in various scales. In particular, we examine mesoscale properties such as the nested structure, the core-periphery structure, and the community structure by statistically investigating their interrelationships with real network data. As a result of community detection on different scales, we find an absence of a meaningful hierarchy between networks, and a negative correlation between the modularity and the two other structures (nestedness and core-periphery-ness), which themselves are highly positively correlated. In addition, no characteristic scale for the communities is perceivable from the community-inconsistency analysis. Therefore, community structures, which are the most widely studied mesoscale structures of networks, are not, in fact, adequate to characterize mutualistic networks of this scale in ecosystems.

Keywords: Ecological network, Mutualistic network, Mesoscale properties of network, Core-periphery structure of network, Community structure of network