Abstract
Environmental and anthropogenic stressors can interact (e.g., drought, harvest or herbivory) to shape plant demography and evolutionary strategies with implications for sustainable resource management plans. Harvest or recurrent biomass removal can act as a selective force. However, our understanding of how harvest and changes in climate can synergistically shape plant evolutionary strategies is limited. We used age-from-stage matrix modeling to investigate how chronic anthropogenic disturbance (severe foliage and bark harvest) affects age-specific mortality trajectories of a tropical tree, Khaya senegalensis in two contrasting climatic regions (dry versus moist) in West Africa. We then developed a stochastic model to test if changes in disturbance regime and the environmental conditions in which a cohort is born may alter stochastic age-specific mortality rates. The effect of harvest on age-specific mortality trajectories was modest and only noticeable in the moist region. Age-specific mortality trajectories differed significantly between regions. In the moist region, mortality rates decreased with age for the first 30 years of life to a minimum rate and then increased gradually after to reach an old age mortality plateau. In the dry region, mortality rates decreased with age to reach a plateau asymptotically. This difference in age-specific mortality trajectory is due to a greater delay in reaching reproductive size/age in the dry region. Our findings underscore intraspecific variation in age-specific mortality schedules and indicate that climatic effect may override the impact of anthropogenic activities on plant demography. Harvest, by favoring fast life stage transition to reproductive stages, can buffer the effect of drought.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 34-40 |
| Number of pages | 7 |
| Journal | Ecological Modelling |
| Volume | 400 |
| DOIs | |
| State | Published - May 24 2019 |
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Keywords
- Age-from-stage
- Age-specific mortality
- Climate change
- Matrix models
- Non-timber forest products harvest
ASJC Scopus subject areas
- Ecological Modeling
Cite this
Climate, rather than human disturbance, is the main driver of age-specific mortality trajectories in a tropical tree. / Gaoue, Orou G.; Horvitz, Carol C.; Steiner, Ulrich K.; Tuljapurkar, Shripad.
In: Ecological Modelling, Vol. 400, 24.05.2019, p. 34-40.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Climate, rather than human disturbance, is the main driver of age-specific mortality trajectories in a tropical tree
AU - Gaoue, Orou G.
AU - Horvitz, Carol C.
AU - Steiner, Ulrich K.
AU - Tuljapurkar, Shripad
PY - 2019/5/24
Y1 - 2019/5/24
N2 - Environmental and anthropogenic stressors can interact (e.g., drought, harvest or herbivory) to shape plant demography and evolutionary strategies with implications for sustainable resource management plans. Harvest or recurrent biomass removal can act as a selective force. However, our understanding of how harvest and changes in climate can synergistically shape plant evolutionary strategies is limited. We used age-from-stage matrix modeling to investigate how chronic anthropogenic disturbance (severe foliage and bark harvest) affects age-specific mortality trajectories of a tropical tree, Khaya senegalensis in two contrasting climatic regions (dry versus moist) in West Africa. We then developed a stochastic model to test if changes in disturbance regime and the environmental conditions in which a cohort is born may alter stochastic age-specific mortality rates. The effect of harvest on age-specific mortality trajectories was modest and only noticeable in the moist region. Age-specific mortality trajectories differed significantly between regions. In the moist region, mortality rates decreased with age for the first 30 years of life to a minimum rate and then increased gradually after to reach an old age mortality plateau. In the dry region, mortality rates decreased with age to reach a plateau asymptotically. This difference in age-specific mortality trajectory is due to a greater delay in reaching reproductive size/age in the dry region. Our findings underscore intraspecific variation in age-specific mortality schedules and indicate that climatic effect may override the impact of anthropogenic activities on plant demography. Harvest, by favoring fast life stage transition to reproductive stages, can buffer the effect of drought.
AB - Environmental and anthropogenic stressors can interact (e.g., drought, harvest or herbivory) to shape plant demography and evolutionary strategies with implications for sustainable resource management plans. Harvest or recurrent biomass removal can act as a selective force. However, our understanding of how harvest and changes in climate can synergistically shape plant evolutionary strategies is limited. We used age-from-stage matrix modeling to investigate how chronic anthropogenic disturbance (severe foliage and bark harvest) affects age-specific mortality trajectories of a tropical tree, Khaya senegalensis in two contrasting climatic regions (dry versus moist) in West Africa. We then developed a stochastic model to test if changes in disturbance regime and the environmental conditions in which a cohort is born may alter stochastic age-specific mortality rates. The effect of harvest on age-specific mortality trajectories was modest and only noticeable in the moist region. Age-specific mortality trajectories differed significantly between regions. In the moist region, mortality rates decreased with age for the first 30 years of life to a minimum rate and then increased gradually after to reach an old age mortality plateau. In the dry region, mortality rates decreased with age to reach a plateau asymptotically. This difference in age-specific mortality trajectory is due to a greater delay in reaching reproductive size/age in the dry region. Our findings underscore intraspecific variation in age-specific mortality schedules and indicate that climatic effect may override the impact of anthropogenic activities on plant demography. Harvest, by favoring fast life stage transition to reproductive stages, can buffer the effect of drought.
KW - Age-from-stage
KW - Age-specific mortality
KW - Climate change
KW - Matrix models
KW - Non-timber forest products harvest
UR - http://www.scopus.com/inward/record.url?scp=85063251012&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85063251012&partnerID=8YFLogxK
U2 - 10.1016/j.ecolmodel.2019.03.007
DO - 10.1016/j.ecolmodel.2019.03.007
M3 - Article
AN - SCOPUS:85063251012
VL - 400
SP - 34
EP - 40
JO - Ecological Modelling
JF - Ecological Modelling
SN - 0304-3800
ER -