Biology subjects

Pyrcz, T.

Publications and source records attributed to Pyrcz, T..

3 recordsLinked to original sources

bioRxiv2024

Climate-driven vegetation characteristics shape phytophagous and carnivorous insect diversity in South African savannahs

Despite the recognized importance of insects in savannah ecosystems, the drivers of their diversity patterns remain poorly understood, particularly in the Afrotropical region. This study addresses this gap by investigating the impacts of climate, habitat, disturbance, and vegetation variables on the diversity of phytophagous moths (Lepidoptera) and carnivorous mantises (Mantodea) across 60 plots in Kruger National Park, South Africa. Based on an extensive dataset of 65,593 moth individuals representing 817 morphospecies and 3,511 mantis individuals representing 38 morphospecies, our results revealed plant communities as the fundamental driver of diversity for both insect groups. The effects of vegetation on insect diversity were indirectly influenced by climate, particularly mean temperature (negatively correlated with precipitation), through its impact on plant species richness. Additionally, a complex interplay among bedrock type, water availability, and disturbances from large herbivores and fire further shaped insect diversity. Our findings highlight the regions vulnerability to climate change, as decreasing precipitation and increasing temperatures were shown to alter vegetation composition and biomass, consequently affecting insect communities. Overall, our results emphasize the necessity of managing large herbivores and regulating fire regimes to maintain diverse vegetation, which is crucial for supporting insect diversity. Effective conservation strategies should prioritize balancing water availability and disturbance intensity, particularly in maintaining the health of seasonal rivers, to mitigate the adverse effects of climate change on these ecosystems.

ecology↗

bioRxiv2021

Role and patterns of butterflies and hawkmoths in plant-pollinator networks at different elevations and seasons in tropical rainforests of Mount Cameroon

O_LIButterflies and moths are well-visible flower visitors. Nevertheless, almost no quantification of their role in plant-pollinator interactions exists at a community level, especially from tropical rainforests. Moreover, we have virtually no knowledge on environmental and other factors affecting lepidopteran flower visits. C_LIO_LIWe focused on the role of butterflies and hawkmoths as flower visitors in tropical rainforests of Mount Cameroon, especially on its elevational and seasonal changes. We also analysed their preferences to selected floral traits, with a specific focus on pollination syndromes. C_LIO_LIWe video-recorded flower visitors of 1,115 specimens of 212 plant species (>26,000 recording hrs) along the complete elevational gradient of rainforests in two main seasons, and compared frequencies of flower-visiting lepidopterans to other visitors. We compared characteristics of plant-lepidopteran networks among elevations and seasons, and analysed patterns of selected lepidopteran traits. Finally, we analysed inter-family differences in their floral preferences. C_LIO_LIAltogether, we recorded 734 flower visits by 80 butterflies and 27 hawkmoth species, representing only ~4% of all 18,439 flower visits. Although lepidopterans visited only a third species, they appeared key visitors of several plants. The most flower visits by lepidopterans were recorded in mid-elevations and dry season, mirroring the general patterns of lepidopteran diversity. The networks showed no apparent elevational or seasonal patterns, probably because of the surprisingly high specialisation of interactions in all networks. Significant non-linear changes of proboscis and forewing lengths were found along elevation, and long-proboscid hesperiid butterflies visited flowers with longer tubes or spurs. Substantial differences in floral preferences were found between sphingids, and papilionid, nymphalid and lycaenid butterflies, revealing importance of nectar production, floral size and shape for sphingids, and floral colour for butterflies. C_LIO_LIButterflies and hawkmoths were confirmed as relatively minor visitors of tropical forest flowers, although they seemed crucial for pollination of some plant species. Moreover, the revealed floral preferences and trait-matchings confirmed a potential of some lepidopteran families to drive floral evolution in tropical ecosystems. C_LI

ecology↗

bioRxiv2020

Does rainforest biodiversity stand on the shoulders of giants? Effect of disturbances by forest elephants on trees and insects on Mount Cameroon

Natural disturbances are essential for dynamics of tropical rainforests, contributing to their tremendous biodiversity. In the Afrotropical rainforests, megaherbivores have played a key role before their recent decline. Although the influence of savanna elephants on ecosystems has been documented, their close relatives, forest elephants, remain poorly studied. Few decades ago, in the unique natural enclosure experiment on Mount Cameroon, West/Central Africa, the rainforests were divided by lava flows which are not crossed by the local population of forest elephants. We assessed communities of trees, butterflies and two ecological guilds of moths in disturbed and undisturbed forests split by the longest lava flow at upland and montane elevations. Altogether, we surveyed 32 forest plots resulting in records of 2,025 trees of 97 species, and 7,853 butterflies and moths of 437 species. The disturbed forests differed in reduced tree density, height, and high canopy cover, and in increased DBH. Forest elephants also decreased tree species richness and altered their composition, probably by selective browsing and foraging. The elephant disturbance also increased species richness of butterflies and had various effects on species richness and composition of all studied insect groups. These changes were most probably caused by disturbance-driven alterations of (micro)habitats and species composition of trees. Moreover, the abandonment of forests by elephants led to local declines of range-restricted butterflies. Therefore, the current appalling decline of forest elephant populations across the Afrotropics most probably causes important changes in rainforest biodiversity and should be reflected by regional conservation authorities.

ecology↗