teixeirak
commented
2 years ago It's a very open canopy-- a savanna, so they are sun exposed. But it's true that that paragraph reads funny, as they are not upper canopy leaves. We need to reword. But that acacia study is consistent with the principle that leaves in a hotter micro environment have higher t50.
@teixeirak, just checking, in the paragraph below, isn't T50 greater with higher composite climate stress in the lower north-facing portions, so these leaves might not be sun leaves right?
Based on their variation with the temperatures experienced by leaves, thermal tolerance metrics are hypothesized to be higher in sun-exposed upper canopy leaves than in understory leaves. Indeed, along a vertical gradient within a very open canopy in Australia, crowns of Acacia papyrocarpa Benth. showed greater $T{50}$ and higher composite climate stress in the lower, north-facing portions of their crowns than in other crown positions, correlating with low wind speed, greater radiation and $T{air}$, and lower rates of heat dissipation, as indicated by longer leaf thermal time constants [@curtis_intracanopy_2019].