Abstract Anthropogenically induced climate change is expected to increase the intensity and frequency of natural disturbances like floods and droughts, with serious potential consequences for wetlands. While there have been some studies that have investigated the impact of hurricanes (tropical cyclones) on coastal wetlands, there are gaps in spatially quantifying the impacts of other extreme meteorological events on inland wetlands. We addressed this gap by studying the impacts of severe flooding, caused by a deep cut-off low system in September 2023, on wetlands in southern Africa. This study aimed to spatially quantify biogeomorphic changes in the wetlands following the flood event, using freely available remote sensing data from before and after the event, and to establish the best method for this analysis. Three methods were applied to detect changes, namely digitization, index analysis and change detection. For the index analysis, the effectiveness of the Normalized Difference Vegetation Index (NDVI) and Bare Soil Index (BSI) was explored. From the results of all methods, we found that bare ground increased significantly (t=-6.35, df = 8, p < 0.01) by a mean of 70 000 m 2 (8%) per wetland, while greenness significantly decreased (t = 5.61, df = 8, p < 0.01) with a mean loss of vegetation of 40 000 m 2 following the floods. The most accurate of the automated approaches to mapping post-flood impact on palmiet wetland systems was change detection (89%). Leveraging applications in remote sensing using freely available imagery presents a critical opportunity to study and interrogate tipping points in wetlands in data-constrained regions.

Interactions among plants, herbivores, and natural enemies are central to community ecology, yet most studies focus primarily on diurnal patterns, overlooking temporal variation across the day–night cycle. Here, we describe the composition and temporal dynamics of arthropod assemblages associated with Ipomoea carnea (Convolvulaceae), a widespread extrafloral nectary-bearing macrophyte in the Brazilian Pantanal. Over one year, we surveyed 30 plants monthly across three daily periods (morning, afternoon, and night), documenting herbivores (specialists and generalists) and natural enemies (ants, wasps, and spiders). We recorded 1,996 herbivores and more than 19,000 natural enemies, of which ants accounted for 71% of all records, highlighting their dominant role in the system. Arthropod assemblages exhibited clear temporal partitioning: ants were more abundant during daylight periods and coincided with lower herbivore abundance, whereas spiders peaked at night and were associated with reduced occurrence of specialist herbivores. Wasps were less abundant overall but showed activity concentrated during daytime. Together, these patterns indicate complementary temporal associations among natural enemy guilds across the daily cycle, suggesting sustained temporal associations between natural enemies and herbivores across the diel cycle. Our findings highlight I. carnea as a natural platform for investigating arthropod community dynamics and provide a valuable baseline for ecological theory and conservation efforts in one of the world’s most threatened wetlands.

Peatland drying, driven by global warming and human impact alters nitrogen (N) cycling, potentially affecting gaseous and fluvial N fluxes, N stores in peat and in the underlying mineral subsoil, as well as the peat and subsoil N content and stable isotope (15N/14N) proportions (δ15N). Complete peat columns may reveal effects of past climatic periods and drainage for forestry on N stratigraphy within the peat. We measured N concentrations and δ15N values in peat and subsoil at undrained and drained peatlands in Finland. On three peatlands having paired natural and drained sites, we quantified changes in N, 15N and 14N storage, and calculated δ15N values of the lost or gained N for bog having three synchronous layers on undrained and drained sites. There was preferential downward transfer of 15N in the uppermost peat of drained bog. Also, the subsoil beneath the drained fen had increased δ15N values compared to undrained site. δ15N values were generally below zero, except in one bog and in the subsoil under a fen. In peat layers dating to the Mid-Holocene, high dry bulk density, C%, N%, and humification index, coupled with low C/N ratio, were connected to the highest δ15N values in profile, similarly to those observed at the surface peat δ15N maxima. Drainage decreased total N content and transferred N from upper peat layers to deeper strata. In opposite to expectations, on peatlands having parallel undrained and drained sites, δ15N value increase or decrease was not connected clearly to decreased N mass.