An adapted typology of tree-related microhabitats including tropical forests

Laurent Larrieu a collaboré en tant que co-auteur à un article sur l'adaptation de la typologie des dendromicrohabitats aux forêts tropicales publié dans le journal Ecological Indicators.

En collaboration avec des collègues allemands qui travaillent en milieu tropical, une série de relevés effectués dans des forêts d’Equateur et de Tanzanie ont permis de proposer ici quelques compléments à la typologie des dendromicrohabitats (dmh) qui sert actuellement de référence dans les forêts tempérées, méditerranéennes et boréales afin de pouvoir l’utiliser en forêt tropicale. Ils proposent l’ajout d’une nouvelle forme de dmh (les formations racinaires) et de trois nouveaux groupes : les concavités formées par des fruits ou des feuilles, les dendrotelmes (car séparés ici des autres concavités) et les formations racinaires aériennes.

Nußer R., Bianco G., Kraus D., Larrieu L., Feldhaar H., Schleuning M., Müller J. (2024). An adapted typology of tree-related microhabitats including tropical forests. Ecological Indicators 167, 112690 https://doi.org/10.1016/j.ecolind.2024.112690

Il s’agit d’un premier jet qui devra être corroboré/complété par de plus amples échantillonnages afin de couvrir la grande variabilité de ces forêts tropicales. La principale difficulté a été de rassembler les données taxonomiques permettant de considérer ces structures originales comme des dendromicrohabitats, car peu d’études ont été consacrées jusqu’alors à la biodiversité liée à ces structures. Ils ont profité de ces données pour comparer les assemblages de dmh observés dans les forêts tropicales de basse altitude avec ceux des forêts tropicales de haute altitude, mais aussi avec ceux des hêtraies tempérées.

Abstract: Abstract

Tree-related microhabitats (TreMs) describe the microhabitats that a tree can provide for a multitude of other taxonomic groups and have been proposed as an important indicator for forest biodiversity. So far, the focus of TreM studies has been on temperate forests, although the tropics provide a large forest area, with different types of forest and a high diversity of tree species, some of them with exceptionally high numbers of TreMs. In this study, TreMs in the lowland tropical forests of the Chocó (Ecuador) and in the mountain tropical forests of Mount Kilimanjaro (Tanzania) were surveyed. Our results extend the existing typology of TreMs of Larrieu et al. (2018) to include tropical forests and enabled a comparison of the relative recordings and diversity of TreMs between tropical and temperate forests. A new TreM form, Root formations, and three new TreM groups, concavities build by fruits or leaves, dendrotelms, and root formations, were established. In total, 15 new TreM types in five different TreM groups were specified. The relative recordings of most TreMs were similar between tropical and temperate forests. However, ivy and lianas, and ferns were more common in the lowland rainforest than in temperate forests, and bark microsoil, limb breakage, and foliose and fruticose lichens in tropical montane forest than in lowland rainforest. Mountain tropical forests hosted the highest diversity for common and dominant TreM types, and lowland tropical forest the highest diversity for rare TreMs. Our extended typology of tree-related microhabitats can support studies of forest-dwelling biodiversity in tropical forests. Specifically, given the ongoing threat to tropical forests, TreMs can serve as an additional tool allowing rapid assessments of biodiversity in these hyperdiverse ecosystems.