Stefan Hohnwald

Comparing floristic composition in treefall gaps of certified, conventionally managed and natural forests of northern Honduras

Abstract• Forest certification sets requirements for minimizing the impacts of logging on the natural structure and floristic composition of forests.• We assessed the impact of certification by comparing the floristic composition of 52 taxa of trees and shrubs in the treefall gaps of certified, conventionally managed and protected forests in northern Honduras.• The highest abundance of light-benefiting taxa was found in certified forests, whereas conventionally managed forests were floristically more similar to natural forests. The environmental conditions measured in certified gaps were not favourable for a natural forest floristic composition.• Past logging may have altered the species composition in certified forests relatively more than in conventionally managed forests. This implies that the need for restoration operations should be considered in certification requirements, along with landscape-level planning to enhance post-logging recovery.Résumé• La certification forestière définit des exigences pour minimiser les impacts de l’exploitation forestière sur la structure naturelle et la composition floristique des forêts.• Nous avons évalué l’impact de la certification, en comparant la composition floristique de 52 taxons d’arbres et d’arbustes dans les trouées d’abattage d’arbres de forêts certifiées, conventionnellement gérées et protégées du Nord du Honduras.• La plus grande abondance des taxons profitant de la lumière a été trouvée dans les forêts certifiées, alors que les forêts gérées de façon conventionnelle ont été floristiquement plus proches des forêts naturelles. Les conditions environnementales mesurées dans les trouées certifiées n’étaient pas favorables à une composition floristique de forêt naturelle.• L’exploitation forestière passée, peut avoir modifié la composition des espèces dans les forêts certifiées relativement plus que dans les forêts gérées. Cela implique que le besoin d’opérations de restauration doit être pris en compte dans les exigences de certification.

Carbon-optimised land management strategies for southern Amazonia

The Brazilian Amazon region is perceived a most precious biome due to its various globally relevant functions and resources. The Amazon forest is considered a key control for the global and regional climate system (Trumbore et al. 2015; Coe et al. 2017) and is a principal driver for the global and regional water cycle (Castello and Macedo 2016; Getirana 2016; Gimeno et al. 2012). It is home to a unique share of Earth’s genetic resources (Laurance et al. 2012; Pimm et al. 2014; Myers et al. 2000) as well as a rich human cultural heritage which includes indigenous populations yet unexplored (Walker et al. 2016; Pringle 2014). The Brazilian savannah ecosystems, known as Cerrado, add another set of unique wildlife habitats (Simon et al. 2009). Both ecosystems represent important resources for the Brazilian and global economy, yet there are still serious issues regarding sustainable natural resources management. Up until today, the ongoing destruction of both ecosystems has stirred attention worldwide. More than 750,000 km of pristine forest has been lumbered in the Amazon between 1970 and 2013 (Nogueira et al. 2015; INPE 2017). During this period, deforestation rates have steadily increased until 2003/2004 (INPE 2014; Nepstad et al. 2014), and then slowed down as a result of political will and enforcement until 2013 (Boucher et al. 2013; Hansen et al. 2013; Nepstad et al. 2014). Since then, its rate is again increasing (Schönenberg et al. 2015; INPE 2016). Similarly, the Cerrado has also become subject to significant land use change (Jepson 2005; Beuchle et al. 2015; de Oliveira et al. 2017). The conversion of both ecosystems into cattle pastures and agricultural land already considerably affected biodiversity (Lees and Peres 2006), but also carbon (C) stocks and emissions, and the consequences for environment