Drought reduces the growth and health of tropical rainforest understory plants

Background

Plant responses to drought are important to understand for agricultural practices and environmental stress. Susceptibility to drought varies among and between plant species. Most field studies on plant responses to drought in tropical rainforests ignore understory plant species such as saplings and shrubs. These species are important to understand because they are often more vulnerable to environmental stressors, and they contribute greatly to forest biodiversity.

Goals and Methods

The authors aim to understand the effects of short-term drought on tropical rainforest tree saplings and shrubs, and if drought would reduce aboveground biomass and physiological performance. This study is conducted in the Daintree Rainforest Observatory in Northeastern Australia. The authors use a rainfall exclusion structure to create experimental conditions and tree sapling and shrub species are measured across six months.

Conclusions and Takeaways

The authors conclude that both tree saplings and shrubs show significantly reduced aboveground biomass when subjected to drought. These plants show a higher vulnerability to diseases, insect attacks, and reduced photosynthesis. Overall, these plants react very strongly to drought and it is important to consider their responses when assessing rainforest community resilience.