TY - JOUR
T1 - Disturbance history modulates how litter and herbaceous cover influence conifer regeneration after fire
AU - Gill, Nathan S.
AU - Jarvis, Daniel
AU - Rogan, John
AU - Kulakowski, Dominik
N1 - Funding Information:
We thank Tom Veblen and the field teams that assisted with plot establishment and data collection, including Amanda Bracket, Moriah Day, Mary Malloy and Sarah Whitcher. We thank Jaclyn Guz and four anonymous reviewers for their comments on earlier drafts of this article. This work was supported by the National Science Foundation under grants 1262691 and by a National Science Foundation Graduate Research Fellowship. Any findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
Publisher Copyright:
© 2020 IAWF.
PY - 2020/6
Y1 - 2020/6
N2 - Climate-driven increases in disturbance frequency and extent augment the potential for compounded disturbances. Drawing on well-studied forests that experienced successive disturbances, we asked: (1) how does post-fire cover of litter, herbaceous cover and bare ground vary between stands affected by combinations of blow-down, insect outbreak, and fire? (2) How do post-fire relationships between ground cover and conifer regeneration vary with recent disturbance history? We measured ground cover and conifer regeneration from 2003 to 2014 following stand-replacing fires in 2002. Burned stands were either blown down in 1997, affected by a 1940s Dendroctonus rufipennis (spruce beetle; SB) outbreak, or neither. Implementing mixed-effects models, we measured the relationships between pre-fire stand attributes (structural stage, canopy dominance and combination of disturbances) and post-fire ground cover and between post-fire ground cover and conifer regeneration. Fire-only stands had more litter and herbaceous cover post fire than other stands (P < 0.05). Fir regeneration increased with litter in stands that only burned, but decreased with litter in stands that were first blown down. Similarly, pine and fir regeneration increased with herbaceous cover after fire-only, but did the opposite in stands affected by the SB outbreak. Pre-fire legacies can modulate the effects of ground cover on plant regeneration.
AB - Climate-driven increases in disturbance frequency and extent augment the potential for compounded disturbances. Drawing on well-studied forests that experienced successive disturbances, we asked: (1) how does post-fire cover of litter, herbaceous cover and bare ground vary between stands affected by combinations of blow-down, insect outbreak, and fire? (2) How do post-fire relationships between ground cover and conifer regeneration vary with recent disturbance history? We measured ground cover and conifer regeneration from 2003 to 2014 following stand-replacing fires in 2002. Burned stands were either blown down in 1997, affected by a 1940s Dendroctonus rufipennis (spruce beetle; SB) outbreak, or neither. Implementing mixed-effects models, we measured the relationships between pre-fire stand attributes (structural stage, canopy dominance and combination of disturbances) and post-fire ground cover and between post-fire ground cover and conifer regeneration. Fire-only stands had more litter and herbaceous cover post fire than other stands (P < 0.05). Fir regeneration increased with litter in stands that only burned, but decreased with litter in stands that were first blown down. Similarly, pine and fir regeneration increased with herbaceous cover after fire-only, but did the opposite in stands affected by the SB outbreak. Pre-fire legacies can modulate the effects of ground cover on plant regeneration.
KW - beetle outbreak
KW - blow-down
KW - compounded disturbance
KW - facilitation
KW - ground cover
KW - post-fire regeneration
KW - subalpine forest
UR - http://www.scopus.com/inward/record.url?scp=85079224833&partnerID=8YFLogxK
U2 - 10.1071/WF19028
DO - 10.1071/WF19028
M3 - Article
AN - SCOPUS:85079224833
SN - 1049-8001
VL - 29
SP - 519
EP - 529
JO - International Journal of Wildland Fire
JF - International Journal of Wildland Fire
IS - 6
ER -