Cattle browsing impacts on stunted Avicennia marina mangrove trees

•This study provides quantitative data on the effect of cattle browsing on mangrove trees.•Removal of cattle from exclusion plots resulted in a significant increase in mangrove tree height.•Cattle browsing reduced the numbers of flowers and fruits.•Trampling and browsing also resulted in fewer seedlings in the browsed plots.•Browsing influenced tree morphology causing horizontal spreading of branches. Mangroves in South Africa are threatened by over-utilization through harvesting for firewood and building materials as well as excessive browsing and trampling by livestock. At Nxaxo Estuary (32°S; 28°E) the response of Avicennia marina to cattle browsing and trampling was investigated by using exclusion plots. These were established by fencing in five 25m2 quadrats and adjacent to each experimental quadrat a browsed quadrat. Trees were tagged and measured annually from 2010 to 2012. Sediment salinity, pH, moisture, organic content, compaction as well as sediment particle size did not differ between browsed and non-browsed quadrats. Significant increases in mean tree height (5.41±0.53cm), crown volume (0.54±0.01m3) and crown diameter (7.09±0.60cm) from 2010 to 2012 were recorded for the non-browsed plots. Trees in the browsed plots had significantly lower growth (p