Loading...
2 results
Search Results
Now showing 1 - 2 of 2
- Arthropod-based biotic integrity indices: A novel tool for evaluating the ecological condition of native forests in the Azores archipelagoPublication . Tsafack, Noelline; Lhoumeau, Sébastien; Prieto Contreras, Laura Alejandra; Navarro, Loic; Kocsis, Timea; Manso, Sónia; Figueiredo, Telma; Teresa Ferreira, Maria; Borges, Paulo A. V.ABSTRACT: Island ecosystems are experiencing a significant decline in biodiversity, with forest biodiversity being particularly affected by several biodiversity erosion drivers. This alarming situation highlights the urgent need for conservation managers to develop more accurate and efficient tools to assess and monitor the quality status of sites. To address this issue, our study focuses on the development of two biological integrity indices (IBI) that utilize arthropod communities as indicators to measure the quality of forest sites. In accordance with studies that showed stratification of species diversity, we developed an IBI for canopy stratum (IBI-Canopy) and an IBI for an intermediate stratum targeting the forest understory (IBI-SLAM). We calibrated both indices on seven parameters for comparison purpose with a previous developed epigean IBI. Percentages of endemic, native non-endemic and introduced species richness and abundance were included in both indices. Percentages of Diplopoda species richness and abundance were included in IBI-Canopy and percentages of Saprophagous species richness and abundance were included in IBI-SLAM. As expected species richness and abundance of endemic species were negatively related to disturbance and selected for both IBI. Surprisingly, species richness and abundance of native non-endemic species were positively related to disturbance. The study highlights the limitations of single measurements in detecting all types of pressure sources, and proposes a multi-measurement system to provide a more comprehensive understanding of the overall system conditions. Our efficient and accessible indices confirmed low preservation status in Flores Island compared to Terceira and Pico, consistent with prior empirical studies. Our analyses also showed that canopy detect disturbance earlier than intermediate understory stratum. Our methodology has successfully been developed and tailored to the unique arthropod communities found in the Azores forests. While it may not be suitable for random forest sites, it can serve as a valuable source of inspiration for the development of arthropod-based IBIs in other islands of the world for which standardized endemic and exotic species richness and abundance could be obtained. The study also showed that arthropod assemblages mimicked forest biodiversity stratification and this is reflected in differences expressed by the IBIs.
- Biological Integrity of Azorean Native Forests Is Better Measured in Cold SeasonPublication . Tsafack, Noelline; Lhoumeau, Sébastien; Ros Prieto, Alejandra; Navarro, Loic; Kocsis, Timea; Manso, Sónia; Martins Figueiredo, Telma; Ferreira, Maria Teresa; Borges, P.A.V.ABSTRACT: The Azorean archipelago, recognized as one of the world’s biodiversity hotspots, is home to a diverse and unique community of arthropod species, highlighting a notable degree of endemism. However, the native forests that support these species are facing significant degradation due to habitat loss and fragmentation. In this study, we aimed to determine the ideal season for measuring the biological integrity of forest sites using a biological integrity index (IBI) based on arthropod communities captured with Sea, Land, and Air Malaise (SLAM) traps. Drawing on more than thirty years of research experience in the Azorean forests, we selected twelve reference sites, six representing preserved native forest and six representing disturbed native forest, and compared how IBI values vary between seasons. IBI values exhibited consistent variations between seasons in disturbed sites, indicating that measuring the biological integrity in these areas can be conducted at any time of the year without a specific seasonal preference. In contrast, significant differences were observed in pristine forest sites, with the winter season and the combination of winter and spring data (cold semester) showing notably higher values compared to other seasons and semesters. This finding suggests that measuring the biological integrity of preserved sites is best optimized in the cold seasons, while the detection of exotic species impact is most effective in summer and autumn. Consequently, if resources are limited, monitoring efforts should be concentrated in the winter and summer seasons to obtain the maximum and minimum values of IBI, respectively. Additionally, our study suggests that the summer season is the optimal time to detect potentially invasive exotic species.