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Abstract Understanding mechanisms that generate range limits is central to knowing why species are found where they are and how they will respond to environmental change. There is growing awareness that biotic interactions play an important role in generating range limits. However, current theory and data overwhelmingly focus on abiotic drivers and antagonistic interactions. Here we explore the effect that mutualists have on their partner's range limits: the geographic “footprint” of mutualism. This footprint arises from two general processes: modification of a partner's niche through environment‐dependent fitness effects and, for a subset of mutualisms, dispersal opportunities that lead suitable habitats to be filled. We developed a conceptual framework that organizes different footprints of mutualism and the underlying mechanisms that shape them, and evaluated supporting empirical evidence from the primary literature. In the available literature, we found that the fitness benefits and dispersal opportunities provided by mutualism can extend species' ranges; conversely, the absence of mutualism can constrain species from otherwise suitable regions of their range. Most studies found that the footprint of mutualism is driven by changes in the frequency of mutualist partners from range core to range edge, whereas fewer found changes in interaction outcomes, the diversity of partners, or varying sensitivities of fitness to the effects of mutualists. We discuss these findings with respect to specialization, dependence, and intimacy of mutualism. Much remains unknown about the geographic footprint of mutualisms, leaving fruitful areas for future work. A particularly important future direction is to explore the role of mutualism during range shifts under global change, including the promotion of shifts at leading edges and persistence at trailing edges. 

Abstract Mutualism benefits partner species, and theory predicts these partnerships can affect the abundance, diversity, and composition of partner and non‐partner species. We used 16 years of monitoring data to determine the ant partner species of tree cholla cacti (Cylindropuntia imbricata), which reward ants with extrafloral nectar in exchange for anti‐herbivore defense. These long‐term data revealed one dominant ant partner (Liometopum apiculatum) and two less common partners (Crematogaster opuntiaeandForelius pruinosus). We then used short‐term characterization of the terrestrial ant community by pitfall trapping to sample partner and non‐partner ant species across ten plots of varying cactus density. We found that the dominant ant partner tended a higher proportion cacti in plots of higher cactus density, and was also found at higher occurrence within the pitfall traps in higher density plots, suggesting a strong positive feedback that promotes ant partner occurrence where plant partners are available. Despite the strong association and increased partner occurrence, ant community‐wide effects from this mutualism appear limited. Of the common ant species, the occurrence of a single non‐partner ant species was negatively associated with cactus density and with the increased presence ofL. apiculatum. Additionally, the composition and diversity of the ant community in our plots were insensitive to cactus density variation, indicating that positive effects of the mutualism on the dominant ant partner did not have cascading impacts on the ant community. This study provides novel evidence that exclusive mutualisms, even those with a strong positive feedback, may be limited in the scope of their community‐level effects. 

Natural and artificial approaches are the mainly management strategy used in degraded lands restoration, while few studies examine the effect of the two strategies on soil nutrient properties in an earthquake-triggered degraded ecosystem. We compared soil chemical traits and major nutrient stoichiometry from areas following landslides that had undergone natural restoration (D. NR.) and artificial restoration (D. AR.), as well as neighboring undisturbed areas (Und.), following the 2017 magnitude 7.0 earthquake in Jiuzhaigou, eastern Qinghai-Tibet Plateau. The results showed that soil organic carbon (C), total nitrogen (N), available nitrogen (AN), available phosphorus (AP), exchangeable calcium (eCa), exchangeable magnesium (eMg), C/P, C/K, N/P, N/K, P/K, cation exchange capacity, and vegetation cover in landslides of D. NR. and D. AR. were lower than those in Und. land, while their pH and total potassium (K) concentration were higher. Compared to D. NR., most of these traits were higher in D. AR., except for the C/N, which was reduced in D. AR. Soil C was positively related to AN, C/K, N/P, N/K, P/K in each land type, while in D. NR., it was not related to N, AP, AK, eCa, eMg, C/N, although it was negatively related to P and K concentration. The findings demonstrated that vegetation restoration strategies could affect not only soil nutrient content but also the macronutrient stoichiometry (N, P, K). Furthermore, artificial restoration projects can enhance soil nutrient concentration and facilitate vegetation recovery more quickly than natural restoration, which is primarily driven by soil N rather than P or K. 

With a growing body of literature on the topic of ecosystem service (ES), there is an urgent need to summarize ES research in the context of ecological restoration programs (ERPs) in China and identify knowledge gaps for future directions. We conducted a systematic literature review of articles to examine the use of ES approaches for ERP assessments. Our results showed that previous studies mainly focused on the Shaanxi Province, and more than half of the reviewed studies considered no more than three ES types simultaneously. All ES categories were not covered equally; most of the studies focused on provisioning and regulating services, while cultural services have received little attention. Although regional-scale and short-term assessments dominated the reviewed papers, we suggest that multiple temporal and spatial scales for ERP assessments should be given more attention in future work. Moreover, we highlight that an oversimplified land use/land cover (LULC) categorization scheme may potentially lead to inaccuracies and biases in ESs detection under restoration programs. Based on this review, our findings can guide future ERP assessments by using the ES approach. Meanwhile, given the global LULC change brought by the proliferation of plantations under ERPs, our results are also expected to provide a path forward to assess ESs associated with LULC change globally. 

1. Historical datasets can establish a critical baseline of plant–animal interactions for understanding contemporary interactions in the context of global change. Pollen is often incidentally preserved on animals in natural history collections. Techniques for removing pollen from insects have largely been developed for fresh insect specimens or historical specimens with large amounts of pollen on specialized structures. However, many key pollinating insects do not have these specialized structures and thus, there is a need for a method to extract pollen from these small and fragile insects. 2. Here, we propose a precision glycerine jelly swab tool to allow for the precise removal of pollen from old, small and fragile insect specimens. We use this tool to remove pollen from five families of insects collected in the late 1970s. Additionally, we compare our method with four previously published techniques for removing pollen from pinned contemporary specimens. 3. We show the functionality of the precision glycerine jelly swab for removing small quantities of pollen across insect families. We found that across the five methods, all removed pollen; yet, it was clear that some are better suited for fragile specimens. In particular, the traditional glycerine jelly swab and the precision glycerine jelly swabs both performed well for removing pollen from bee faces. The shaking wash resulted in specimen fracture and residue left behind, the ethanol rinses left setae matted, and the glycerol swabbing left residue on the specimen. Additionally, we present photographs documenting the effects of these methods on pinned honey bee specimens. 4. The precision glycerine jelly swab opens up opportunities to sample pollen from a variety of insects in natural history collections. These pollen samples can be incorporated into downstream analyses for pollen identification either via mi-croscopy or DNA sequencing, and the resulting plant–insect interaction data can establish historical baselines for contemporary comparison. Beyond our ap-plication of this method to pollen on insects, this precision glycerine jelly swab tool could be used to explore pollen placement specialization or to sample bryo-phyte, fungal and tree fern spores dispersing on animals.