Exploring the forestry potential of two legume species with contrasting ecological strategies in a seasonally dry tropical region

Key message Plantations of two multipurpose legume species markedly differ in stand development and functioning. The sustainability of tree plantations can be inferred from their ecological strategies along the fast-slow economic spectrum. Growing plantations with native trees is crucial for ecosystem restoration and wood and non-wood product supply, but silvicultural guidelines are lacking. The growth, survival, biomass allocation, nutrient accumulation and nutrient use efficiency, C-13 isotopic composition, canopy openness, and solar radiation in understory and grass cover were assessed in monoculture plantations of fast [Schizolobium parahyba var. amazonicum (Huber & Ducke) Barneby], and slow [Anadenanthera peregrina var. peregrina (L.) Speg.] growing species in the Brazilian Atlantic Forest. Nine experimental plots per species and a stand density of 1111 trees ha(-1) were examined 6 years after planting. The mean values of wood density were higher in A. peregrina than S. parahyba trees, with 0.66 g cm(-3) and 0.27 g cm(-3), respectively. S. parahyba trees showed 75% higher stem-wood biomass, with five times less leaf biomass than A. peregrina trees. However, contrasting diameter growth and survival rates resulted in comparable stand above-ground biomass between species. Macronutrient content and delta C-13 composition differences showed that S. parahyba exhibits higher nutrient use while A. peregrina has higher intrinsic water efficiency. Grass was abundant in the S. parahyba plantations and suppressed in the A. peregrina plantations, in line with the observed canopy openness and solar radiation in the understory. Functional traits allow the prediction of the contrasting silvicultural potentials of A. peregrina (wood production and microclimate recovery) and S. parahyba (timber production and agroforestry).

Automated summary

Plantations of two multipurpose legume species differ significantly in stand development and functioning, with the fast-growing species showing advantages in timber production and nutrient use efficiency, while the slow-growing species excels in water use efficiency and agroforestry.