Data from: The roots of the drought: hydrology and water uptake strategies mediate forest-wide demographic response to precipitation
Chitra-Tarak, Rutuja, Smithsonian Institution
Ruiz, Laurent, University of Toulouse, French National Institute for Agricultural Research
Dattaraja, H. S., Indian Institute of Science Bangalore
Kumar, M. S. Mohan, Smithsonian Institution
Riotte, Jean, University of Toulouse
Suresh, H. S., Indian Institute of Science Bangalore
McMahon, Sean M., Smithsonian Institution
Sukumar, Raman, Indian Institute of Science Bangalore
Published Dec 15, 2018 on Dryad.
Cite this dataset
Chitra-Tarak, Rutuja et al. (2018). Data from: The roots of the drought: hydrology and water uptake strategies mediate forest-wide demographic response to precipitation [Dataset]. Dryad. https://doi.org/10.5061/dryad.nm3d3
Drought-induced tree mortality is expected to increase globally due to climate change, with profound implications for forest composition, function and global climate feedbacks. How drought is experienced by different species is thought to depend fundamentally on where they access water vertically below ground, but this remains untracked so far due to the difficulty of measuring water availability at depths at which plants access water (few to several tens of meters), the broad temporal scales at which droughts at those depths unfold (seasonal to decadal), and the difficulty in linking these patterns to forest-wide species-specific demographic responses. We address this problem through a new eco-hydrological framework: we used a hydrological model to estimate belowground water availability by depth over a period of two decades that included a multi-year drought. Given this water availability scenario and 20yr long-records of species-specific growth patterns, we inversely estimated the relative depths at which 12 common species in the forest accessed water via a model of water-stress. Finally, we tested whether our estimates of species relative uptake depths predicted mortality in multi-year drought. The hydrological model revealed clear belowground niches as precipitation was decoupled from water availability by depth at multi-annual scale. Species partitioned the hydrological niche by diverging in their uptake depths and so in the same forest stand, different species experienced very different drought patterns, resulting in clear differences in species-specific growth. Finally, species relative water uptake depths predicted species mortality patterns after the multi-year drought. Species that our method ranked as relying on deeper water were the ones that had suffered from greater mortality, as the zone from which they access water took longer to recharge after depletion. This research changes our understanding of how hydrological niches operate for trees with a trade-off between realized growth potential and survival under drought with decadal scale return time. The eco-hydrological framework highlights the importance of species-specific below ground strategies in predicting forest response to drought. Applying this framework more broadly may help us better understand species-coexistence in diverse forest communities and improve mechanistic predictions of forests productivity and compositional change under future climate.
This file contains growth dynamics for 12 common tree species by size class over 20 years (4-yr time step) in the 50 ha Mudumalai Forest Dynamics Plot.
This file contains 20-yr long (1988-2008) annual abundance dynamics for 12 common tree species (>= 5 cm DBH) in the 50 ha Mudumalai Forest Dynamics Plot (MFDP).
This file contains 20-yr long (1988-2008) annual mortality dynamics for 12 common tree species (>=5 cm DBH) in the 50 ha Mudumalai Forest Dynamics Plot.
This file provides taxonomic information corresponding to the codes used in the other files for the 12 common species.
This file contains 24 yr long (1990-2013) daily rainfall record at Kargudi weather station, 4 km away from the 50 ha Mudumalai Forest Dynamics Plot.
National Science Foundation, Award: 1137366;1046113