Monthly Archives: May 2025

NEW PAPER OUT

Kunwar, A., Gélin, U.,  Subedi, N., Regmi, S., Tomlinson, K.W.*, Herbivory and fire influence soil and plant nutrient dynamics in Chitwan National Park, Nepal, 2025, Global Ecology and Conservation 60, e03610, https://doi.org/10.1016/j.gecco.2025.e03610.

Abstract

In the context of global biodiversity loss and climate change, understanding how herbivores and fire shape plant-soil nutrient dynamics across vegetation types has become a global priority. In tropical Asia, the combined effects of herbivore assemblages, fire regimes, and plant community diversity on nutrients remain poorly understood. We investigated how herbivory and fire influence soil nutrients (nitrogen (N), phosphorus (P), potassium (K), and cation exchange capacity (CEC)) and plant nutrients (N, P, K), across five vegetation types – two forests (riverine, Shorea) and three grasslands (tall, short, grazing lawn) in Chitwan National Park, Nepal. Across 50 plots (400 m2 each), we quantified mammalian herbivory pressure using dung counts, fire frequency using satellite data, and analyzed 150 soil and 187 plant samples for nutrient concentrations. Herbivore dung and fire frequency varied markedly across habitats: herbivores were largely absent from tall grasslands while present in all other vegetation types, whereas fires were rare in short grassland and grazing lawns but frequent in tall grassland and forests. Overall, forests had higher soil and plant nutrient concentrations than grasslands. Soil N, K, and CEC increased with increasing dung counts across vegetation types, whereas plant K decreased with increasing dung counts only in Shorea forests and grazing lawns. Soil P and CEC increased, while plant N, P and K decreased with increasing fire frequency across vegetation types. For the two forest types, interactions between dung and fire counts decreased soil P, plant N and plant P in riverine forest but had no effect in Shorea forest. These findings highlight the additive and interactive impacts of herbivory and fire on nutrient cycling, emphasizing the need to manage disturbance regimes to sustain soil fertility, habitat quality, and biodiversity resilience in tropical landscapes.

For more details on papers published from this group, click here.

NEW PAPER OUT

Putra, A.A., Nurainas,  Phoncharoen, W.,   Agung, A.P., Zhao, Y.,  Tomlinson, K.W.*, Grassland diversity across an aridity gradient in northern Sumatra is strongly associated with shifts in disturbance regimes, 2025, Global Ecology and Conservation, 60, e03619,
https://doi.org/10.1016/j.gecco.2025.e03619.

Abstract

Grassy vegetation is widely spread across Southeast Asia, yet very little data exists describing the diversity in these plant communities. Groundlayer diversity data is especially rare, with previous studies focussing on woody plants. Research in grassy ecosystems worldwide suggest that there are substantial differences in grassland community composition across climate aridity gradients, which are aligned with a switch from strong disturbance by fire in wetter sites to disturbance by mammalian herbivory in drier sites. The aim of this investigation was to record the groundlayer diversity of grasslands found in northern Sumatra Island, Indonesia, and to determine whether that diversity was structured fire and mammalian herbivory. We sampled ten 50 m x 50 m vegetation plots in grassy vegetation across an aridity gradient, with soil data and grazing pressure data collected on site, and climate and fire frequency data compiled from geographic resources. We classified all species according to two morphological characteristics that related to plant evolution under fire and herbivory, namely stem form and leaf placement. We recorded 89 groundlayer species across all plots, with an average of 29 species per plot. Our analysis confirmed that the strongest axis of community differentiation was with respect to the fire-grazing trade-off axis, which selected for specific adaptive stem and leaf placement morphologies. The groundlayer diversity of grasslands in northern Sumatra is closely related to other monsoonal regions of Southeast Asia, likely reflecting grassland connectivity during the last ice age. The abundance of disturbance-adapted species suggests appropriate use of fire and herbivory will be necessary to sustain these communities.

For more details on papers published from this group, click here.