Ecology and Distribution of the Malesian Podocarps

Abstract

ABSTRACT. Podocarp species and genus richness is higher in the Malesian region than anywhere else on earth, with maximum genus richness in New Guinea and New Caledonia and maximum species richness in New Guinea and Borneo. Members of the Podocarpaceae occur across the whole geographic and altitudinal range occupied by forests and shrublands in the region. There is a strong tendency for podocarp dominance of vegetation to be restricted either to high-altitude sites close to the limit of tree growth or to other sites that might restrict plant growth in terms of water relations and nutrient supply (e.g., skeletal soils on steep slopes and ridges, heath forests, ultramafic parent material). Although some species are widespread in lowland forests, they are generally present at very low density, raising questions concerning their regeneration ecology and competitive ability relative to co-occurring angiosperm tree species. A number of species in the region are narrowly distributed, being restricted to single islands or mountain tops, and are of conservation concern. Our current understanding of the distribution and ecology of Malesian podocarps is reviewed in this chapter, and areas for further research are identified.

Two tropical conifers show strong growth and water-use efficiency responses to altered CO2concentration

“…Evergreen species have increased in abundance in a range of ecosystems, although the drivers of these changes are not always clear (Niinemets et al, 2011, and references therein). Podocarps are currently patchily distributed across the lowland and montane tropics, and for the most part are restricted to low-fertility habitats, where soil nutrient availability constrains realized growth rate (Adie and Lawes, 2011;Dalling et al, 2011;Enright and Jaffré, 2011;Punyasena et al, 2011). Contemporary increases in c a that improve the growth performance of tropical forest conifers relative to angiosperm trees might therefore be expected to influence their abundance and distribution.…”

“…Despite these apparent limitations on the competitive ability of lowland tropical conifers, two families, Araucariaceae and Podocarpaceae, remain locally important components of some forests, particularly on nutrient-poor soils Enright and Jaffré, 2011;Kitayama et al, 2011). Furthermore, recent work suggests that podocarps colonized tropical latitudes only in the last 60 million years, and after the diversification of major angiosperm lineages (Jaramillo et al, 2011a, b;Morley, 2011;Quiroga et al, 2016).…”

Fossil forests in the Austral Basin (Argentina) marking a Cenomanian heterogeneous forced regressive surface

“…The other two podocarps from the southern Andes, Podocarpus saligna Don. Although they are characterized by seasonal waterlogging and low levels of mineral nutrient availability, they support high stem densities of small-diameter trees, typically 20-25 cm diameter breast height (dbh; Whitmore, 1984;Newbery et al, 1986;Enright & Jaffr e, 2011). ex Endl.)…”

“…ex Endl.) Drought stress is thought to be a major driver of podocarp forest structure and composition, with shallow root systems (a response to seasonal waterlogging) leading to increased vulnerability during dry periods (Enright & Jaffr e, 2011). In northern South America, Prumnopitys montana (Humb.…”

Chemical Diversity of Podocarpaceae in New Caledonia: Essential Oils from Leaves of Dacrydium, Falcatifolium, and Acmopyle Species

“…Thefamilycomprises 18 genera and 173 species,e ssentiallyd istributed in tropical and subtropical regionso ft he southern hemisphere [1].I ts genus richness is higher in the Malesian region and in New Caledonia, where ad istinctive conifer flora has evolvedo na ccount of its geological history and its isolation in the southwestern Pacific Ocean. The20endemic species of Podocarpaceae in New Caledonia belong to eight genera: Podocarpus, Dacrydium, Retrophyllum, Falcatifolium, Dacrycarpus, Acmopyle, Prumnopitys,a nd Parasitaxus [2] [3].…”