A Newly Identified Role of the Deciduous Forest Floor in the Timing of Green‐Up

Abstract

Plant phenology studies rarely consider controlling factors other than air temperature. We evaluate here the potential significance of physical and chemical properties of soil (edaphic factors) as additional important controls on phenology. More specifically, we investigate causal connections between satellite‐observed green‐up dates of small forest watersheds and soil properties in the Adirondack Mountains of New York, USA. Contrary to the findings of previous studies, where edaphic controls of spring phenology were found to be marginal, our analyses show that at least three factors manifest themselves as significant controls of seasonal patterns of variation in vegetated land surfaces observed from remote sensing: (1) thickness of the forest floor, (2) concentration of exchangeable soil potassium, and (3) soil acidity. For example, a thick forest floor appears to delay the onset of green‐up. Watersheds with elevated concentrations of potassium are associated with early surface greening. We also found that trees growing in strongly acidified watersheds demonstrate delayed green‐up dates. Overall, our work demonstrates that, at the scale of small forest watersheds, edaphic factors can explain a significant percentage of the observed spatial variation in land surface phenology that is comparable to the percentage that can be explained by climatic and landscape factors. We conclude that physical and chemical properties of forest soil play important roles in forest ecosystems as modulators of climatic drivers controlling the rate of spring soil warming and the transition of trees out of winter dormancy.

Photoperiod decelerates the advance of spring phenology of six deciduous tree species under climate warming

“…In addition, extending the findings of this regional study to the global scale would require consideration of interactions with other environmental factors, such as precipitation, soil moisture, and diurnal temperature range (Laube et al, 2014; Meng, Zhou, et al, 2020). Besides climate conditions, physical and chemical properties of soil such as the concentration of exchangeable soil potassium and soil acidity are also shown to have a significant impact on spring phenology at the scale of small forest watersheds (Lapenis et al, 2017).…”

Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO2

“…Static allometric relationships over time can introduce bias where environmental changes have altered resource allocation. For example, shifting allocation from wood to leaves in Russian forests reconciled apparently conflicting inventory data that suggested BP declines, while remote sensing suggested increases (Lapenis et al, 2017). Furthermore, wood volume growth does not always scale with BP as wood density can also change (Pretzsch et al, 2018).…”

A comparison of ground-based methods for obtaining large-scale, high-resolution data on the spring leaf phenology of temperate tree species

“…Phenology at the local level varies according to species composition and genetic diversity (Basler 2016;Cleland et al 2007;Polgar and Primack 2011). Environmental factors such as topography (Fisher et al 2006) and soils (Arend et al 2016;Lapenis et al 2017) can vary markedly over small spatial gradients, and influence phenology at scales missed by remote-sensing.…”