Seagrass ecosystem trajectory depends on the relative timescales of resistance, recovery and disturbance
O'Brien, Katherine R. ; Waycott, Michelle ; Maxwell, Paul ; Kendrick, Gary A. ; Udy, James W. ; Ferguson, Angus J.P. ; Kilminster, Kieryn ; Scanes, Peter ; McKenzie, Len J. ; McMahon, Kathryn ; Adams, Matthew P. ; Samper-Villarreal, Jimena ; Collier, Catherine ; Lyons, Mitchell ; Mumby, Peter J. ; Radke, Lynda ; Christianen, Marjolijn J.A. ; Dennison, William C. - \ 2018
Marine Pollution Bulletin 134 (2018). - ISSN 0025-326X - p. 166 - 176.
Colonizing - Opportunistic - Persistent - Recovery - Resilience - Resistance - Seagrass - Trajectory
Seagrass ecosystems are inherently dynamic, responding to environmental change across a range of scales. Habitat requirements of seagrass are well defined, but less is known about their ability to resist disturbance. Specific means of recovery after loss are particularly difficult to quantify. Here we assess the resistance and recovery capacity of 12 seagrass genera. We document four classic trajectories of degradation and recovery for seagrass ecosystems, illustrated with examples from around the world. Recovery can be rapid once conditions improve, but seagrass absence at landscape scales may persist for many decades, perpetuated by feedbacks and/or lack of seed or plant propagules to initiate recovery. It can be difficult to distinguish between slow recovery, recalcitrant degradation, and the need for a window of opportunity to trigger recovery. We propose a framework synthesizing how the spatial and temporal scales of both disturbance and seagrass response affect ecosystem trajectory and hence resilience.
Variation in host preferences of malaria mosquitoes is mediated by skin bacterial volatiles
Busula, A.O. ; Takken, W. ; Boer, J.G. De; Mukabana, W.R. ; Verhulst, N.O. - \ 2017
Medical and Veterinary Entomology 31 (2017)3. - ISSN 0269-283X - p. 320 - 326.
Anopheles arabiensis - Anopheles gambiae - Anthropophilic - Attraction - Bacteria - Host finding - Microbiota - Odours - Opportunistic - Vectors - 017-4008
The host preferences of the anthropophilic mosquito species in the Anopheles gambiae complex (Diptera: Culicidae) are mediated by skin bacterial volatiles. However, it is not known whether these mosquitoes respond differentially to skin bacterial volatiles from non-human host species. In this study, the responses of two malaria mosquito species in the An. gambiae complex, Anopheles gambiae s.s. (hereafter, An.gambiae) and Anopheles arabiensis, with different host preferences, to volatiles released from skin bacteria were tested. Skin bacteria collected from human, cow and chicken skin significantly increased trap catches; traps containing bacteria collected from human skin caught the highest proportions of An.gambiae and An.arabiensis. Traps with bacteria of human origin caught a significantly higher proportion of An.gambiae than of An.arabiensis, whereas bacterial volatiles from the chicken attracted significantly higher numbers of An.arabiensis than of An.gambiae. Additionally, An.gambiae showed a specialized response to volatiles from four specific bacteria, whereas An.arabiensis responded equally to all species of bacteria tested. Skin bacterial volatiles may therefore play important roles in guiding mosquitoes with different host preferences. The identification of these bacterial volatiles can contribute to the development of an odour blend that attracts mosquitoes with different host preferences.