Understanding the ecology of tree-seedling growth in dry tropical environment: a management perspective

Abstract

The dry tropical forests are among the most vulnerable ecosystems of the world and, however, are relatively understudied. These forests provide various ecosystem services, and are progressively being converted into patches of dry scrubs, savanna and marginal cropland systems, due to various anthropogenic perturbations. Soils of these regions are relatively nutrient poor with a patchy nutrient and water distribution pattern. Therefore, the variability in these natural resources imposed by the present climate change scenario may affect the forest plant community of dry tropics via its impact on seedling growth and recruitment. Seedlings are considered as the most sensitive stage of plant lifecycle, and therefore, understanding of seedling regeneration may help in restoration of forest ecosystems. Seedling growth is majorly regulated by various naturally occurring resources (such as light, water, nutrient, etc.) and disturbances (such as defoliation, grass competition, fire, etc.). Therefore, efforts on the regeneration of these forest systems are highly necessitated. In the present study, we critically reviewed the studies on seedling survival and growth under different resource and disturbance regimes with a special focus to dry tropical environment. We found that water, light, nutrients, herbivory, and grass competition majorly regulates recruitments, growth, and establishment of the tree seedling in dry tropical environment. Most of the studies are limited to observe the effect of one or two factors over the seedling survival and growth. However, the resources and disturbances may have an interactive effect over seedling growth. Therefore, studies encompassing the interactions of various growth factors (resources and disturbances) under different climatic conditions are urgently needed for the successful regeneration of tree seedlings and for the restoration of plant community. Moreover, it will improve our ability to manage the tropical vegetation under changing climatic scenario.

Effects of light availability on leaf attributes and seedling growth of four tree species in tropical dry forest

“…Amount of light available on the forest floor has been reported as a strategic environmental regulator which governs intrinsic growth behavior of residing plant species (Augspurger 1984;Walters and Reich 1996;Bhadouria et al 2018). Heterogeneity in the availability of light in a forest is associated with morphological and physiological adaptations, and therefore directly determines the species composition at community level (Lüttge et al 2002;Bhadouria et al 2016Bhadouria et al , 2017a. Valladares and Niinemets (2008) suggested that the understanding of species-specific response to acclimatize and grow in low-light environments will help in the assessment of ecosystem responses to global climate change.…”

Floristic similarity between adult and saplings strata of Caatinga hyperxerophilous woody vegetation – a Brazilian seasonally tropical dry forest

“…Prolonged drought periods may favor increased similarity between strata of woody vegetation, as humidity is an important filter for less rustic seedlings [51], [52], [18], especially for species with wide variation of phenological behavior and for those with low abundance of individuals in the adult stratum, resulting in interannual variation of seed production and germination and, consequently, of individuals able to be recruited.…”

Assessing Context-Specific Factors to Increase Tree Survival for Scaling Ecosystem Restoration Efforts in East Africa

“…Furthermore, seedling source plays a key role in the viability of planting material and is often overlooked in tree planting campaigns [28]. This is because seedling stage is considered the most sensitive stage in the lifecycle of trees and seedling care from early establishment is critical to survival [35,46]. Tree seedlings distributed to farmers were sourced from different nurseries across the study sites due to the large number of seedlings required and the structure of nursery enterprises in the area, that is, most nurseries are smallholder owned and run.…”