Estimating the global geomorphological importance of ants in the Anthropocene

<p>Ants are active, numerous and widespread across most landscapes on Earth. They are known to be geomorphologically important, through a range of activities (such as production of galleries and mounds) by which they move and store sediment both above and below ground. They also co-exist and interact with a wide range of other geomorphologically-active organisms, sometimes resulting in complex influences on the landscape (as ant mounds can influence soils and plant biodiversity, for example). Human impacts in the Anthropocene are having direct and indirect impacts on the geomorphological importance of ants – through species invasions, climate change etc. A geolocated database of over 100 studies, covering more than 60 ant species, carried out in Europe, Africa, South America, southern Africa, USA and Australia, is used to produce some estimates of the global impacts of ants within the Anthropocene, including a first order estimate of 7.5 – 10 Gt sediment moved per year by ants across the land surface.</p>

Zoogeomorphosite: A concept for, and example of, linking geoheritage and biodiversity heritage

<p>Zoogeomorphosites can be defined as geomorphological sites of special interest for animal biodiversity and conservation. They appear as ideal places for linking geoheritage and biodiversity heritage because of the reciprocal effects and interactions between landforms and animals. On one hand, geomorphodiversity exerts an influence on animal biodiversity at alpha, beta and gamma levels, and many landforms constitute valuable habitats for a wide range of animal species. On the other hand, animals can have direct and indirect geomorphic effects by creating specific landforms (e.g., mounds) and by influencing geomorphic processes (e.g, runoff), respectively.</p><p>The aim of this presentation is (1) to illustrate a worldwide range of sites fitting the conceptual definition of a zoogeomorphosite, with a proposed typology, and (2) to present an example of zoogeomorphological survey conducted on a site in Northwest France (Bois-des-Jarries, Vendée), where geoheritage meets with biodiversity heritage. The selected study site is a granitic geomorphosite composed of two hills with small tors and boulders outcropping at 230-260 m a.s.l., and franging a large fluvial paleo-valley of Ypresian age. The land cover is a mosaic of mixed forests and dry heathlands recognized for their high ecological interest, with many valuable species of vascular plants, birds and invertebrates. A major zoogeomorphic interest of the site is that it hosts an important population of mound-building red wood ants (<em>Formica rufa</em>), a regionally rare and vulnerable species responsible for an impressive collection of biogenic microlandforms (ant mounds) on a small surface (62 ha). A zoogeomorphogical survey carried out in summer 2020 on these ant mounds involved a two-stage methodology: (1) linear surveys along forest paths, in order to calculate mound densities and to proceed with a general inventory of ant mounds; (2) morphometric measurements of mounds using strip transects in 13 representative habitat types, in order to calculate mound volumes and to evaluate their evolution on a 5-years period.</p><p>119 mounds of <em>Formica rufa</em> have been inventoried in summer 2020 along the forest paths, indicating a density of 2-4 mounds ha<sup>–1</sup>. First results of the morphometric measurements indicate that the highest biovolumes are found in pine or mixed forest habitats, and that the geomorphology of the granitic hills (slope, aspect, height above drainage, etc.) is of major influence on their distribution and shape. In turn, ant mounds create environmental heterogeneity, or patch-scale geodiversity, highly favourable to biodiversity, notably because they offer microhabitats for various myrmecophilous insects. Finally, ant mounds can be viewed as a remarkable example of biogeomorphological heritage, hybrid and evolutionary in nature, but highly sensitive to environmental and human-induced changes (e.g., forest clear cuts, tourism pressure). Because ant mounds are an integral component of natural heritage and a key provider of ecosystem services, their inventory and protection as zoogeomorphosites – just like that of termite mounds – are of prime relevance in the wider scope of integrating geodiversity and biodiversity in nature conservation policies and strategies.</p>

The correlation analysis between ant mounds and plant resource in Olkhon region

Olkhon region in East Siberia has abundant and unique vegetation and animal resource for its peculiar geographic location, including ants. Ant, recognized as ecosystem engineers, has an important role in ecosystem. In order to investigate the ecological role of mound-building ants in this region, we focused our attention on the correlation between the distribution of ant mounds and plant species. Five quadrats (5 m × 5 m) were set up in this region, each of which was then divided into twenty-five quadrats (1 m × 1 m). We collected the location of every Black Bog Ant (Formica candida) mound, the number and biomass of various plants in every small quadrat. Using matrices, we tested the distribution pattern of ant mound randomly. The correlation between plants and ant mound pattern was tested by correlation analysis and regression analysis. The result showed that the spatial distribution of ant mound was random. We also found that Artemisia frigida, Carexduriuscula and Oxytropis sylvesfris had a significant linear relationship with the spatial distribution of ant mound (P < 0.05), suggesting that the spatial distribution of ant mound was dependent on the spatial distribution of some plants. The underlying mechanism was further studied. We attributed this correlation to the feeding habits and foraging strategies of Black Bog Ant and tissue structure of these three plants. Our study figured out the interaction between Black Bog Ant and plant resource in Olkhon region, laying down the foundation for future study on the co-evolution of plant and animal resource in this unique ecosystem.

Biogeomorphological research frontiers: from ant mounds to Mars

&lt;p&gt;Biogeomorphology is a vibrant area of scientific research which focuses on the two-way interrelationships between ecological and geomorphological processes across a wide range of temporal and spatial scales. Whilst ecological influences on geomorphology were often perceived in the past as a rather niche topic, most geomorphologists now &amp;#160;consider the ecological dimension as being crucial to the evolution and behaviour of geomorphological systems. However, there is still much to be done to explore the intersections between ecology and geomorphology. It is now timely to investigate what frontier research in biogeomorphology might look like over the coming years. This paper explores some characteristics of frontier research (addressing scientific controversies, focusing on hard-to-answer questions, employing atypical methods and concepts, being paradigm-challenging, and having a high risk of failure) in the context of tomorrow&amp;#8217;s biogeomorphology. As examples, the paper addresses current progress in research on the geomorphological contributions of ants on Earth, and microbial biosignatures on Mars.&lt;/p&gt;

Morphology, reproduction, habitat use, and hibernation of Red-bellied Snake (Storeria occipitomaculata) near its northern range limit

Northern regions limit ectotherms to relatively short periods of feeding and breeding interrupted by long periods of inactivity. This may force cool-climate ectotherms into different ecological or demographic trade-offs than their southern conspecifics. Our aim is to examine demography, morphology, reproduction, habitat use, and hibernation by populations of Red-bellied Snake (Storeria occipitomaculata) near their northern range limit. This research was conducted in southwestern Manitoba and data on summer activity were collected from April to September 2007–2009 using coverboard and pedestrian surveys. Hibernation sites were monitored over three winters (2007–2008, 2008–2009, and 2009–2010), and thermal profiles of Formica ant mounds were collected in 2008–2009 and 2009–2010. Females reached sexual maturity at a smaller size than most other populations that have been reported but appear to have similar clutch sizes to the rest of the range. The majority of adult females captured at our summer sites were gravid (96%) suggesting annual reproduction, and activity patterns suggest fall breeding. Near its northern range maxima, this species appears to use relatively warm habitat, have rapid reproduction, and co-opt ant mounds to survive in a difficult climatic environment. Much remains unknown and future studies should further examine the variation in size at maturity and the relationship between body size and clutch size. In addition, little is known about diet, benefits of fall mating, use of open prairie habitats, and late-season migration by S. occipitomaculata.

Habitatselektion von zwei Waldameisenarten (Formica rufa und F. polyctena)

Habitat selection of two wood ant species (Formica rufa and F. polyctena) Wood ants play an important role in the forest ecosystem, but knowledge about their spatial distribution is often outdated or scarce in Switzerland. Species-specific habitat requirements remain poorly understood, especially for the two sympatric species Formica rufa and F. polyctena, preventing the development of efficient conservation measures. Following the survey of wood ant mounds in the cantons of Basel-Landschaft and Basel-Stadt of 2015/2016, we developed a predictive hierarchical habitat model to investigate the relationships between habitat characteristics (slope, canopy cover, canopy height, vertical structure, distance to forest edge, distance to forest roads, proportion of conifers, and proportion of forest area) and the nest density of F. rufa and F. polyctena. By doing so, we adjusted for imperfect detectability of our census method. Most of the habitat factors have been derived from remote-sensing data (LiDAR, false-color images). We found that the two species differ in their smallscale habitat preferences, especially regarding canopy cover, slope and distance to forest edge. Compared to F. polyctena, F. rufa has less marked habitat preferences and is relatively indifferent to canopy height, proportion of forest area and distance to forest edge. Our results are inconsistent with the claim from other studies that F. rufa occurs more frequently at forest edges than F. polyctena. Furthermore, our study emphasizes the need to take into account the detection probability for a large-scale survey of wood ant mounds.