Global seed supply is too poorly understood to even speculate on its contribution to the regeneration of forests that are increasingly lost to disturbance, climate change, and extensive human management. To address this knowledge gap, the MASTIF project was established through collaborations with over 100 international researchers. The MASTIF project, funded by Nation Science Foundation (NSF) to PI Jim Clark since 1990s, has assimilated seed production data for 12.1 million tree-years in more than 1000 species from all vegetated continents. Currently, PI Qiu and Clark are expanding these efforts by linking seed production to seedling recruits and synthesizing satellite and airborne remote sensing with the MASTIF network. This new project, funded by the National Aeronautics and Space Administration (NASA) from 2024 to 2028, invovles collaboration with the Pennsylvania Department of Conservation and Natural Resources (PA DCNR). As a key partner and end-user, PA DCNR will contribute in-kind resources and computing support to aid in the development of decision-making tools. So far, we have addressed the following questions:

• Tree size and age effects: does tree fecundity decline as tree grows larger and older (Qiu et al., 2021a)?
• Map of life and traits: are there limits to reproductive potential whereby species sacrifice seed size in order to produce more seeds, a size-numbers tradeoff (Qiu et al., 2022)?
• Masting syndrome: what are the causes and consequences of mast seeding at a global scale (Qiu et al., 2023)?
• Soil nutrient effects: will access to resources mediate the limits to reproduction (Qiu et al., 2022)?
• Canopy nutrient effects: how will tree fecundity respond to canopy nutrients, including N, P, K, Ca, and Mg (Qiu et al., 2024)?
• Temperature and moisture effects: how does individual fecundity change along the latitude gradient from dry tundra to wet tropics (Journe et al., 2022)?
• Forest regeneration: do forest communities reorganize throughout the tree life stages including adult trees, fecundity, and seedling recruitment (Qiu et al., 2021b)?
• Continental climate extremes: how will continental-scale fecundity respond to climate extremes such as late frost and summer drought (Clark et al., 2025)?

I have featured several main published papers listed in the following. There are a couple of papers in revision (terrain effects and forest migration) and in preparation (effects of phenology and solar radiation), with results available by contacting PI Qiu and Clark.