The Brazilian Cerrado is one of the most endangered biomes in the world. We evaluated the sustainability of leaf harvest in one of the most important Cerrado tree species, Stryphnodendron adstringens. The bark of this tree is used as a source of medicinal tannin. Harvesting bark, however, often kills the tree. In a manipulative field experiment, we tested the hypothesis that harvesting leaves, which might serve as an alternative source of tannin, would be less detrimental for tree survival, growth, reproduction, and defense than harvesting bark. In a two-way crossed experimental design, we either clipped 100% of a plant’s leaves or applied NPK fertilizer to the soil. Our predictions of the experimental outcomes were based on plant resource and defense theory. Growth was determined by total leaf dry mass production, reproduction by inflorescence and fruit production traits, and defense by total phenolics, hydrolyzable tannins, and condensed tannins. Fertilization had a marginally positive effect on total leaf dry mass. Defoliation had no effect on subsequent leaf production, and most importantly, no plants died as a result of defoliation. We found high tannin amounts in leaves of S. adstringens produced both prior to and subsequent to clipping, further suggesting that leaves could serve as a sustainable alternative source of tannin. After clipping, plants invested more in tannin production and less in reproduction. Our results suggest that leaf harvest may be more sustainable than harvesting of bark in S. adstringens. We suggest the need for further investigation of the medicinal properties of leaf tannins to formulate a viable sustainable management plan for the exploitation of this plant species.

Warming global temperatures are expected to strongly influence plant communities, yet there is limited knowledge of how these changes will interact with stressors such as the invasion of exotic earthworms. We conducted a small-scale microcosm experiment to assess the individual and interactive effects of warming and exotic anecic earthworms (<i>Lumbricus terrestris</i> L.) on the growth of sugar maple seedlings (<i>Acer saccharum</i> Marsh.). After fifty days, the elevated temperature chamber created warmer and drier soil conditions and increased several measures of plant growth, including stem width, stem width : stem height ratio, stem biomass, and fine root biomass. Earthworms did not have any clear impacts on plant growth either on their own or in interactions with the temperature chambers. However, earthworms did reduce surface leaf litter cover and exposed soils, which could exacerbate evaporative losses and moisture stress in field soils resulting from a warming climate under different growing conditions. Future studies should consider long-term earthworm-temperature interactions on sugar maple growth as well as diurnal and seasonal changes in temperature.

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