Four ways to define the growing season

Area of Science:

• Ecology
• Plant Physiology
• Global Change Biology

Background:

• The growing season is a key determinant of global plant biomass production.
• A well-defined concept of the growing season is currently lacking.
• Existing definitions may not accurately reflect plant productivity.

Purpose of the Study:

• To differentiate and define various concepts of the growing season.
• To investigate the implications of these definitions for understanding plant growth and biomass.
• To assess the predictive power of the 'window of opportunity' for net primary production (NPP).

Main Methods:

• Conceptual analysis of growing season definitions.
• Distinguishing between growing season sensu stricto, phenological season, productive season, and meteorological season.
• Hypothesizing the predictive relationship between the 'window of opportunity' and NPP.

Main Results:

• Four distinct facets of the growing season were identified: sensu stricto (actual growth), phenological, productive (net carbon gain), and meteorological.
• The duration of the 'window of opportunity' is hypothesized to be a strong predictor of NPP globally, particularly in forests.
• Common assumptions linking phenology solely to productivity may be misleading.

Conclusions:

• Clear definitions of the growing season are essential for accurate ecological modeling.
• The concept of a 'window of opportunity' offers a new perspective on predicting global NPP.
• Rethinking the relationship between phenology and productivity is necessary for understanding climate change impacts.