Implications of large-scale iron fertilization of the oceans

Abstract

As everyone old enough to read a newspaper knows, tropical forests are being destroyed at a stunning pace. In the mere 10 min it will take you to read this, an area of tropical forest the size of 60 football fields will be felled, while another 20 playing fields will be selectively logged. Such forest loss is leading to massive habitat fragmentation. In the Brazilian Amazon, for example, the area of forest that is fragmented (forest <100 km2 in area) or prone to edge effects (<1 km from clearings) is over 150% larger than that actually deforested (Skole and Tucker, 1994). As the 15 articles in this special issue attest, the biotas in fragmented habitats are plagued by an array of threatening processes. Investigations like these are not only relevant to human-dominated landscapes; most nature reserves in the tropics are limited in size some appallingly so and are themselves becoming fragments as the intervening lands are rapidly deforested. Clearly, the fate of the worlds tropical biotas will be largely governed by the capacity of species to survive in fragmented landscapes, and on our ability to manage such landscapes to help mitigate the effects of forest loss and isolation.