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Previous studies have revealed the importance of short‐term bed‐level change on the long‐term development of intertidal ecosystems. One of the recent advancements in the short‐term bed dynamics observation is the developments of laser‐based surface elevation dynamics (LSED) and acoustic surface elevation dynamics (ASED) sensors. These two sensors are developed to automatically monitor tidally induced bed‐level changes, and their measuring windows are during emergent and submerged periods, respectively. So far, there is no direct comparison or joint application of these two sensors. Therefore, in the current study, we first compare their observation precision in both laboratory and field conditions. Results show that both sensors' measurements are in good agreement with the manual measurements in the flume (R2 > 0.99) and field (R2 ≈ 0.70), indicating the applicability of each sensor in natural environment. Finally, a coupled system (i.e., combining LSED and ASED) is established in a mangrove wetland and both sensors show good agreement with each other (R2 = 0.69). Results also demonstrate that the coupled observation system can well capture the bed‐level change during emergent and submerged conditions, which provides detailed continuous data sets to study the bed‐level dynamics within a tidal cycle. Furthermore, large‐scale monitoring systems can also be established via mobile network module embedded in the sensor, providing real‐time monitoring for bed‐level changes, which is valuable to coastal morphological research and vital for detecting deterioration of coastal ecosystems and the services they provide to be able to apply adaptive management. [ABSTRACT FROM AUTHOR]

Mechanical disturbance from waves and sediment dynamics is a key bottleneck to mangrove seedling establishment. Yet, how species vary in tolerance to sediment dynamics has not been quantified. We identified how tolerance to sediment dynamics differs for three mangrove propagule traits: propagule size, successional stage, and type of embryo development. We selected eight mangrove species growing in south China that vary from small seeds to large elongated propagules, pioneer to climax species, and non‐viviparous to viviparous. In a mesocosm set‐up, we applied bed level treatments to establishing seedlings: erosion, control, or accretion, by removing 2 cm, 0 cm, or adding 1 cm of sediment per week over 3 weeks. We measured seedling survival, shoot, and root lengths, and the critical erosion depth that leads toppling or dislodgement. We identified five relationships between seedling morphology and accretion and erosion thresholds: (1) tall (viviparous) propagules likely had highest accretion thresholds; (2) small pioneer propagules grew relatively fast to increase accretion thresholds; (3) there was a strong correlation between the erosion threshold and root length; and (4) climax species grew longest roots overall, (5) while pioneer species grew longer roots fast in response to sediment erosion. We identify distinct strategies for successful establishment in sediment dynamics that contribute to understanding mangrove zonation and underpin the importance of restoring diverse forests containing not just robust climax species, but also adaptable pioneers. Furthermore, this study reveals maximum shoot and root length as key determinants for seedling stability across species, providing a simple proxy for modeling establishment events. [ABSTRACT FROM AUTHOR]

Use of mangrove ecosystems for coastal flood protection requires reliable predictions of mangrove wave attenuation, especially if this capacity lessens due to storm‐induced forest damage. Quantifying and understanding the variation in drag forces and mechanical properties of mangrove vegetation can improve assessment of mangrove protective capacity. We studied five mangrove species common in the subtropical Pearl River Delta, south China. The studied species range from typically landward‐occurring to more seaward‐occurring pioneer species. We sampled across seven sites in the delta to study the impact of salinity on mechanical properties. We quantified strength and flexibility of branches (branch strength and flexibility related to branch diameter, modulus of rupture and modulus of elasticity), leaf strength (leaf attachment strength related to leaf size, and leaf mass per area) and drag properties (drag force related to surface area and drag coefficient). For all tested species, larger branch diameters resulted in higher mechanical strength. Larger leaf size resulted in larger peak pulling forces and larger branch surface area resulted in stronger drag forces. Notably, species that generally occur lower in the intertidal zone, where exposure to wind and waves is higher, had relatively stronger branches but more easily detachable leaves. This may be regarded as a damage‐avoiding strategy. Across the seven field sites, we found no clear effect of salinity on mangrove mechanical properties. This study provides a mechanistic insight in the storm damage process for individual mangrove trees and a solid base for modeling storm (surge) damage at the forest scale. [ABSTRACT FROM AUTHOR]

Context: Evaluating predator management efficacy is difficult, especially when resources are limited. Carefully designing monitoring programs in advance is critical for data collection that is sufficient to evaluate management success and to inform decisions. Aims: The aim was to investigate how the design of camera trap studies can affect the ability to reliably detect changes in red fox (Vulpes vulpes) activity over space and time. Specifically, to examine the effect of study duration, camera cost and detection zone under various environmental and management scenarios, including different fox densities, management impacts, monitoring budgets and levels of spatial and temporal variation. Methods: A generalised linear mixed model was used to analyse simulated datasets from control sites and sites with predator management actions implemented, following a before–after or control–impact sampling design. Statistical power analyses were conducted to evaluate whether a change in fox abundance could be detected across various environmental and management scenarios. Key results: Results showed that a before–after sampling design is less sensitive than a control–impact sampling design to the number of cameras used for monitoring. However, a before–after sampling design requires a longer monitoring period to achieve a satisfactory level of power, due to higher sensitivity to study duration. Given a fixed budget, there can be a trade-off between purchasing a small number of high quality cameras with large detection zones, or a larger number of cameras with smaller detection zones. In a control-impact design we found that if spatial heterogeneity was high, a larger number of cameras with smaller detection zones provided more power to detect a difference in fox abundance. Conclusion: This simulation-based approach demonstrates the importance of exploring various monitoring designs to detect the effect of predator management across plausible environmental and budgetary scenarios. Implications: The present study informs the monitoring design of an adaptive management program that aims to understand the role of managing fox predation on malleefowl (Leipoa ocellata), a threatened Australian bird. Furthermore, this approach provides a useful guide for developing cost-effective camera trap monitoring studies to assess efficacy of conservation management programs. Power analyses are an essential step for designing efficient monitoring, and indicate the strength of ecological signals that can realistically be detected through the noise of spatial and temporal heterogeneity under various budgetary constraints. Carefully designed monitoring programs can strongly aid the evaluation of wildlife management programs. We investigate how the design of a camera trap study can affect the ability to reliably detect changes in red fox populations. This research provides useful guidance for developing cost-effective camera trap monitoring studies. [ABSTRACT FROM AUTHOR]