Influence of mineral nutrient availability on growth of tree seedlings from the tropical deciduous forest

Abstract

Abstract.The effects of different nutrient availabilities on growth and biomass partitioning in seedlings from the tropical deciduous forest in Mexico were compared. The tree species studied were Heliocarpus pallidus, a species associated with disturbed parts of the forest, and Caesalpinia eriotachys, Jacquinia pungens and Recchia mexicana, species from mature, undisturbed habitats. The tropical deciduous tree seedlings were grown in pure silica sand for 50 days inside growth chambers under four nutrient regimes; 5, 20, 100 and 200% Long Ashton nutrient solutions. Data showed contrasting responses among species to different nutrient availabilities. Except Jacquinia pungens, all species had increased growth and productivity as nutrient level increased from 5 to 100%; however, no significant differences in these parameters were detected between 100 and 200% in all species. Compared with mature forest species, pioneer species showed higher variations in biomass production, relative growth rate and net assimilation rate. In contrast to mature forest species, root/ shoot ratios in Heliocarpus pallidus were greater and thus showed higher biomass allocation to roots when nutrient supply was limited. This response suggests higher phenotypic plasticity in pioneer species. Species from mature parts of the forest (Caesalpinia eriostachys, Recchia mexicana) showed less dependency on nutrient supply than pioneer species. These responses appear to support observations from studies with temperate plants investigating growth responses to soil fertility.

Responses to light changes in tropical deciduous woody seedlings with contrasting growth rates

“…The species studied here showed light responses similar to those documented for species adapted to sun and shaded environments (Boardman 1977;Grime 1979;Bazzaz and Pickett 1980;BjoÈ rkman 1981;Smith 1981;Mooney et al 1978Mooney et al , 1983Augspurger 1984;Oberbauer and Strain 1985;Walters and Field 1987;Sims and Pearcy 1989;Denslow et al 1990;Sa nchez-Coronado et al 1990;Lambers and Poorter 1992;Rinco n and Huante 1993;Kitajima 1994). In general, fast-growing species adapted to high light intensity showed higher biomass production, RGR, SLA, rate of photosynthesis per unit of leaf area, and stomatal conductance than species adapted to low light.…”

“…However, the highest RGR values were attained during the ®rst growth period (0±52 days), as in previous studies when these species were grown under abundant resources (Rinco n and Huante 1993Huante , 1994 as well as with dierent pot sizes ; E. Rinco n unpublished work). In the tropical deciduous forest fast growth during the ®rst 1.5 months could have an advantage for seedling establishment in a forest where the rainy period is 4 months long.…”

“…Based on previous growth studies (Rinco n and Huante 1988Huante , 1993Huante , 1994 ten species were chosen to represent a broad range of growth rate, which are listed in Table 1.…”

Foraging for nutrients, responses to changes in light, and competition in tropical deciduous tree seedlings

“…Heliocarpus has a higher growth rate than Caesalpinia (Rinco n and Huante 1993Huante , 1994Huante et al 1995b) and tends to grow in disturbed sites (Lott 1993), but these two species can be found growing together.…”

Effects that nutritional and saline gradients have on the growth of Passiflora mucronata Lam. and Canavalia rosea (Sw.) DC. found in the restinga of Brazil

“…This result indicates that the root system of C. rosea has a higher capacity to develop in less fertile sites, typical of coastal environments where species like Jacquinia pungens also grow, whose roots were affected by an increased availability of nutrients (Rincon & Huante 1994). Therefore, C. rosea has a characteristic of species well adapted to oligotrophic environments, especially as it is a species of Fabaceae with nitrogen-fixing nodules.…”