pristine vegetation are likely to be severely altered by invasions of secondary successional organisms from the large and ever-growing areas under restoration.
If some organisms are to be reintroduced from elsewhere, how far back in time shall we reach? Do we return the Pleistocene horse to Central American dry forest wildlands? How do we do that without adding its predators? If we put the tapir and white-lipped peccary back into El Salvador, do we also bring back their food plants? There are no correct choices per se, but it is clear that certain major dry forest areas must be set aside purely for agriculture and that no effort must be spared to maintain certain other (much smaller) areas as wildlands.
If the goal of restoration ecology is to conserve a maximum number of species, the management plan would be quite different than if the goal is to conserve habitats and interactions with whatever species they normally contain. Management directed at the conservation of a maximum number of species leads at least to the fragmentation of the wildland into a mosaic of successional types and ages and the introduction of species from other areas. If the goal is to conserve interactions as well as species, then the wildland manager must predict rather than simply react. The interactions that are saved will depend on the management steps taken, which depend on the interactions that are desired (and there will be errors and surprise outcomes). Conservation abruptly graduates from the art of patrolling a boundary against poachers to a variety of technical activities, such as the research-based studies of ecological succession, evolutionary biology, species packing, competitive exclusion, and epidemiology.
Rain forest wildlands must be conserved within migratory reach of the dry forest areas that are subject to restoration. A dry forest does not exist unto itself and neither does a rain forest. In Central America, the rain forest and the dry forest are the mutual recipients of each other’s migrants—migrants that are important parts of the interactive structure that holds tropical habitats together. Birds migrating from Wisconsin to Costa Rica are not the only ecological link over large agroscapes.
The dry forest is not only a collection of many kinds of habitats, each rich in unique species, but the members of a given habitat can be important interactants in adjacent habitats. If only certain (usually species-rich) dry forest habitats are slated for conservation, one quickly discovers that a substantial portion of the species in those habitats spend critical parts of their lives in other nearby habitats. To put it another way, the conversion of highly deciduous forest on dry ridges to pasture may have a severely depressing effect on the species-richness of organisms in the very species-rich adjacent alluvial bottomlands.
The dry tropics contain adult remnants of a once thriving forest, juveniles from gradually dwindling seed reservoirs, and waifs from as yet intact wildlands. These organisms now stand on a trashed agroscape and will die without replacement. They are the living dead—all physiologically alive but can be regarded as dead if they were already lying in the litter (Janzen, 1986b). If they flower, they fail to set seed (lack of pollinators). If they set seed, the seeds do not disperse (lack of seed dispersers). If seeds disperse, they do not develop as new members of their population (lack of adequate conditions for growth and development). If they