Importance and Challenges of Biodiversity Research Incorporating Geodiversity

First, a comprehensive review is conducted of recent studies examining the interplay between the diversity of physical geographic environments, primarily shaped by landforms, and biodiversity within mountainous regions. Global warming increases the threat of the extinction of flora and fauna in alpine zones. Meanwhile, the role of landforms and geomorphic processes as refugia for cold-adapted species has garnered attention for potentially mitigating global warming effects. The concept, termed “conserving nature's stage,” emphasizes the importance of geodiversity—the variety of abiotic factors constituting nature's stage—in maintaining biodiversity. Although broad-scale studies suggest a positive correlation between geodiversity and biodiversity, fine-scale research studies are scant. Understanding the impacts of geodiversity on biodiversity at a fine scale, particularly in individual geosites or small natural features (SNFs), is crucial. Biological distributions are influenced by both historical and ecological biogeographic processes, involving organism dispersal with local abiotic and biotic factors. Fine-scale analyses are essential to elucidate these processes, thereby enhancing an understanding of broad-scale distribution patterns and their underlying mechanisms. Second, research conducted on ponds in the mountainous areas of Japan is reviewed. This allowsa emore specific examination of the relationship between geodiversity and biodiversity identified in existing literature reviews. The relationship between geodiversity and biodiversity has been investigated in one of the SNF—mountain ponds in the Northern Japanese Alps. The findings reveal that species-level diversity of aquatic insects and diatoms is shaped by micro- and small-scale landform-induced environmental variations in ponds. In addition, genetic diversity of aquatic insects is influenced by geographic separation and elevation differences between ponds that are governed by medium-scale landforms acting as dispersal barriers. Furthermore, these dispersal barriers also influence diatom species diversity in ponds. Distinct dispersal capabilities of aquatic insects and diatoms within the same watershed—active versus passive—may explain these differences. By integrating findings from these studies on the present-day organisms of mountain ponds with those from investigations on pond sediments, methodological challenges are described in integrating geological, paleoecological, and mountain ecological biogeographic knowledge to reconcile broad-scale and fine-scale patterns of biological distributions.