Phenological diversity among sub-tropical moist forest trees of north-eastern India

Abstract

Analysing phenological diversity of tropical trees provides a potential tool to detect climate change effects and devise forest management options. In this study, the leaf phenological activity of 28 dominant tree species in a moist sub-tropical hill forest of north-eastern India was examined for a period of 2 years and related to functional traits (i.e. leaf mass per area (LMA) and wood density (WD)). The peak phase of leaf fall occurred in the cool dry period (November to January) with leaf flush peaking in the pre-monsoon period (February to March), but variation was found between species as influenced by their phenological strategy, i.e. evergreen, leaf-exchanging or deciduous (<4 months leafless). Photoperiod and minimum temperature were the environmental factors most strongly correlated with phenological activity, and the synchrony index within species for both phenophases was 0.81. LMA was less in the deciduous species compared with the evergreen species, whereas WD did not differ. LMA was negatively correlated with the length of deciduousness as well as timing of leaf flush and fall indicating that LMA may be more important than WD in influencing phenological patterns in this forest. The study revealed that the phenological diversity of tropical trees is related to changes in environmental variables and has implication for forest management under changing climate. Further study will help in understanding the phenological response of trees to climatic factors and their potential future changes.

Spatial Pattern and Key Environmental Determinants of Vegetation in Sand Mining and Non-Mining Sites along the Panjkora River Basin

“…So, the H value not only indicates the number of species but also shows us the abundance of the species distributions in the total number of species among the whole community. Hence, the diversity index value of this study falls within the range reported for tropical forests [48,68]. Species richness along the river basin is influenced by edaphic, biotic and climatic factors [69].…”

“…In contrast, 105 species from mining sites in four districts of Khyber Pakhtunkhwa, Pakistan was reported by [46]. The overall sum of species included in the study was greater than the sum of species listed by other studies; including [47] recorded 92 species from a mid-elevation forest in the Central Himalayas of India, while [48] reported 123 species from a tropical forest in Manipur, north India. Similarly, 85 species from Dulahazara Garjan, Bangladesh by [49], and investigators in tropical forests in various regions of the globe, for example, 89 species were reported by [50], 52 species were recorded by [51], and 94 species was reported by [52].…”

Long-term citizen science data reveals environmental controls on tropical tree flowering at the regional scale

“…Interannual rainfall variability -high rainfall years and drought years including cycles like the El Niño Southern Oscillation and the Indian Ocean Dipole -can result in interannual variability in tree phenophase onset and intensity (Medway 1972, Zimmerman et al 2007, Chang-Yang et al 2016, Chapman et al 2018, Dunham et al 2018, Pau et al 2018. There is a growing understanding of the influence of environmental factors on leaf phenology of tropical species, but information on reproductive phenology is lacking (Chaturvedi et al 2021, Devi et al 2023. To predict future phenological shifts in the tropics, an important first step is to understand the extent of environmental controls on tropical tree reproductive phenology.…”