Conifer Seedling Growth Strategies

Lauren Bansbach, Master's Student, Biology

Abstract

Across western North America, climate change is exacerbating the frequency and intensity of forest fires. These high severity fires physically alter the landscape, often transforming large areas of moist, shady forest to a hotter, drier shrub-dominated ecosystem. This change in habitat and microclimate – the localized temperature and moisture conditions – poses unique challenges to establishing tree seedlings. Seedlings are especially vulnerable to light and water availability due to their limited foliage and roots and thus have evolved growth strategies to maximize survival in their respective ecological niches. What is less understood, however, is how intrinsic seedling growth patterns interact with extrinsic microclimate conditions. Even less is known about the specific response of seedling growth patterns across the arid microclimate of shrub-dominated habitat following severe fire. To fill this knowledge gap, I am studying the seedling growth patterns of four native conifer species across natural microclimates stratified by slope aspect (north/south) and associated vegetation (shrub/grass) across a severely burned area of the Jemez Mountains. Specifically, I am measuring growth parameters such as seedling height, number and length of branches, and chlorophyll fluorescence (an indicator of overall plant health), and analyzing these data with localized microclimate data including rainfall and temperature. With this data, I will learn if seedling growth patterns are intrinsically fixed or extrinsically variable across all microclimates. By understanding how tree seedlings respond to the local microclimate, forest managers can predict which tree species are more likely to naturally regenerate following fire, and which species should be planted where for post-fire restoration.

 
Nov 8th, 2:15 PM Nov 8th, 3:15 PM

Conifer Seedling Growth Strategies

Bobo Room, Hodgin Hall, Third Floor

Across western North America, climate change is exacerbating the frequency and intensity of forest fires. These high severity fires physically alter the landscape, often transforming large areas of moist, shady forest to a hotter, drier shrub-dominated ecosystem. This change in habitat and microclimate – the localized temperature and moisture conditions – poses unique challenges to establishing tree seedlings. Seedlings are especially vulnerable to light and water availability due to their limited foliage and roots and thus have evolved growth strategies to maximize survival in their respective ecological niches. What is less understood, however, is how intrinsic seedling growth patterns interact with extrinsic microclimate conditions. Even less is known about the specific response of seedling growth patterns across the arid microclimate of shrub-dominated habitat following severe fire. To fill this knowledge gap, I am studying the seedling growth patterns of four native conifer species across natural microclimates stratified by slope aspect (north/south) and associated vegetation (shrub/grass) across a severely burned area of the Jemez Mountains. Specifically, I am measuring growth parameters such as seedling height, number and length of branches, and chlorophyll fluorescence (an indicator of overall plant health), and analyzing these data with localized microclimate data including rainfall and temperature. With this data, I will learn if seedling growth patterns are intrinsically fixed or extrinsically variable across all microclimates. By understanding how tree seedlings respond to the local microclimate, forest managers can predict which tree species are more likely to naturally regenerate following fire, and which species should be planted where for post-fire restoration.