FLOODING RESPONSES AND WATER-USE EFFICIENCY OF SUBTROPICAL AND TROPICAL FRUIT-TREES IN AN ENVIRONMENTALLY-SENSITIVE WETLAND

Agriculture is often viewed as having a negative impact on natural eco systems. However, agriculture can contribute to maintaining these ecos ystems by serving as a buffer between natural and urban areas. If agri culture is to coexist with the natural environment, crop production pr actices must be profitable and sustainable. This often requires optimi zing crop productivity while minimizing agricultural inputs. The large st wetland restoration project in history is underway in the Florida E verglades to restore the natural ecosystem by increasing water flows t o re-establish the natural hydrology. This area is also agriculturally unique because it is the only region in the continental United States where several species of subtropical and tropical fruit crops are com mercially grown. In agricultural areas adjacent to Biscayne and Evergl ades National Parks in southern Florida, studies with subtropical and tropical fruit trees are currently aimed at keeping agriculture viable whilst having no negative impact on the natural wetland ecosystem. Re search has focused on determining the effects of continuous and cyclic al flooding on physiology and growth of the major subtropical and trop ical fruit tree species grown in south Florida. Furthermore, attempts are being made to increase crop water-use efficiency to reduce chemica l leaching into the aquifer. This is being done by continuously monito ring soil water content with multi-sensor electrical capacitance probe s and adjusting the soil water content to reduce drainage and leaching of agricultural chemicals below the root zone and to avoid the onset of plant water stress. Crop research methodologies used in south Flori da should be applicable to other areas of the world where sustainable agriculture may be the 'best neighbour' to environmentally-sensitive n atural habitats. (C) 1998 Annals of Botany Company.