Leaf nutrient balance helps explain earlier fall color in US forests
For devout leaf peepers, timing is everything. A new study led by researchers from Duke University's Nicholas School of the Environment shows that leaf nutrient levels affect the onset of fall color. The findings, published in Nature Communications, could improve leaf drop forecasts and carbon cycle tracking.
A recent study published in Nature Communications reveals that the balance of nutrients within deciduous tree leaves influences the timing of fall color change. Led by researchers from Duke University's Nicholas School of the Environment, the findings could enhance predictions of the seasonal leaf drop and improve tracking of the carbon cycle.
As daylight hours shorten, deciduous trees halt chlorophyll production, a pigment responsible for the green hue of leaves, revealing other pigments that give leaves autumnal colors like yellow, orange, and red. Typically, this process begins in late September, with trees shedding their leaves by mid-November. While many deciduous trees in a region start changing color simultaneously, factors like temperature and precipitation can impact the onset of senescence, the process of leaf aging and death.
Nitrogen, phosphorus, and potassium are crucial nutrients for leaf processes, including chlorophyll production and sugar transport. Traditionally, measuring nutrient levels in leaves has been a time-consuming and costly endeavor. However, researchers from Duke University and multiple institutions utilized data from the National Ecological Observatory Network (NEON), which compiles ecological data collected using remote-sensing instruments like satellites and ground-based sensors.
Analyzing spectral data from various ecosystems, the team correlated nutrient ratios with the timing of fall color change in 20 U.S. forests. They discovered that higher nitrogen-to-phosphorus ratios correlated with earlier senescence across all 20 forests, regardless of factors like climate and species composition. Conversely, a higher nitrogen-to-potassium ratio was associated with delayed leaf drop.
An imbalance in nitrogen and phosphorus levels can stress leaves, causing them to prematurely stop photosynthesis and shed their leaves sooner. The study's findings suggest that maintaining the proper nitrogen-to-phosphorus ratio is essential for preserving the health and longevity of vegetation, with implications for agriculture and carbon sequestration efforts.
Written by urgent.news from Phys.org's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
