Interactive effects of defoliation and water deficit on growth, water status, and mortality of black spruce (Picea mariana (Mill.) B.S.P.)
Defoliation followed by water deficit showed time-dependent effects on plant water status and growth in black spruce ( Picea mariana (Mill.) B.S.P.). Biotic stress negatively (during active defoliation by growing instars) and positively (after defoliation) affected plant water relations. However, water deficit, alone or combined with defoliation, prevails over defoliation-related stress for radial growth and sapling vitality.
Tree vitality is influenced by multiple factors such as insect damage, water deficit, and the timing of these stresses. Under drought, positive feedback via the reduction of leaf area may improve the water status of defoliated trees. However, the effect on tree mortality remains largely unknown.
We investigated the effects of defoliation followed by a water deficit on tree growth, plant water status, and mortality in black spruce (Picea mariana (Mill.) B.S.P.) saplings.
In a controlled greenhouse setting, saplings were submitted to combined treatments of defoliation and water stress. To assess the impact of these stresses and their interaction, we measured phenology, twig development, secondary growth of the stem, water potential, and mortality of the saplings.
Both defoliation and water deficits reduced growth; however, the effect was not additive. During active defoliation, we observed a higher evaporative demand and a lower midday leaf water potential Ψmd. We observed an opposite pattern of response post-stress. Drought alone increased sapling mortality immediately after the stress period, but after c.a. 20 days, mortality rates remained similar following combined drought and defoliation.
Our results highlight two key periods during which defoliation affects plant water relations either negatively (during active defoliation) or positively (after defoliation). Mortality in defoliated saplings was reduced immediately following drought because available internal water increased in the stem.
KeywordsBlack spruce saplings Spruce budworm Defoliation Irrigation regimes Bud phenology Primary growth Physiological parameters
We thank S. Rivest for his help in collecting the data.
This study was funded by the “Programme de soutien à la recherche, volet Soutien à des initiatives internationales de recherche et d’innovation (PSR-SIIRI),” the Ministère du Développement économique, Innovation et Exportation du Québec (MDEIE), and the Natural Sciences and Engineering Research Council of Canada (Discovery Grant of A. Deslauriers).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflicts of interest.
- Allen CD, Macalady AK, Chenchouni H, Bachelet D, McDowell N, Vennetier M, Kitzberger T, Rigling A, Breshears DD, Hogg EHT, Gonzalez P, Fensham R, Zhang Z, Castro J, Demidova N, Lim J-H, Allard G, Running SW, Semerci A, Cobb N (2010) A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forests. For Ecol Manag 259:660–684. https://doi.org/10.1016/j.foreco.2009.09.001 CrossRefGoogle Scholar
- Deslauriers A, Fournier M-P, Cartenì F, Mackay J (2019) Spruce budworm defoliation leads to altered carbon allocation and earlier budburst in conifers. Tree Physiol, tpy135. https://doi.org/10.1093/treephys/tpy135
- Dhont C, Sylvestre P, Gros-Louis M-C, Isabel N (2010) Field guide for identifying apical bud break and bud formation stages in white spruce. Natural Resources Canada, QuébecGoogle Scholar
- Eyles A, Pinkard EA, Davies NW, Corkrey R, Churchill K, O’Grady AP, Sands P, Mohammed C (2013) Whole-plant versus leaf-level regulation of photosynthetic responses after partial defoliation in saplings. J Exp Bot 64:1625–1636. https://doi.org/10.1093/jxb/ert017 CrossRefPubMedPubMedCentralGoogle Scholar
- Fernández-de-Uña L, Rossi S, Aranda I, Fonti P, González-González BD, Cañellas I, Gea-Izquierdo G (2017) Xylem and leaf functional adjustments to drought in Pinus sylvestris and Quercus pyrenaica at their elevational boundary. Front Plant Sci 8:1–12. https://doi.org/10.3389/fpls.2017.01200 CrossRefGoogle Scholar
- Giovannelli A, Deslauriers A, Fragnelli G, Scaletti L, Castro G, Rossi S, Crivellaro A (2007) Evaluation of drought response of two poplar clones (Populus×canadensis Mönch ‘I-214’ and P. deltoides Marsh. ‘Dvina’) through high resolution analysis of stem growth. J Exp Bot 58:2673–2683. https://doi.org/10.1093/jxb/erm117 CrossRefPubMedGoogle Scholar
- Páez A, González OME, Yrausquín X, Salazar A, Casanova A (1995) Water stress and clipping management effects on Guineagrass: I. Growth and biomass allocation. Agron J 87:698–706. https://doi.org/10.2134/agronj1995.00021962008700040016x CrossRefGoogle Scholar
- Park Williams A, Allen CD, Macalady AK, Griffin D, Woodhouse CA, Meko DM, Swetnam TW, Rauscher SA, Seager R, Grissino-Mayer HD, Dean JS, Cook ER, Gangodagamage C, Cai M, McDowell N (2013) Temperature as a potent driver of regional forest drought stress and tree mortality. Nat Clim Chang 3:292–297. https://doi.org/10.1038/NCLIMATE1693 CrossRefGoogle Scholar
- Piene H, Maclean DA, Wall RE (1981) Effects of spruce budworm-caused defoliation on the growth of balsam fir: experimental design and methodology. Environment Canada, Canadian Forestry Service, Maritimes Forest Research Centre, FrederictonGoogle Scholar
- Roe AD, Demidovich M, Dedes J (2018) Origins and history of laboratory insect stocks in a multispecies insect production facility, with the proposal of standardized nomenclature and designation of formal standard names. J Insect Sci 18:1–9. https://doi.org/10.1093/jisesa/iey037 CrossRefPubMedCentralGoogle Scholar
- Salleo S, Nardini A, Raimondo F, Lo Gullo MA, Pace F, Giacomich P (2003) Effects of defoliation caused by the leaf miner Cameraria ohridella on wood production and efficiency in Aesculus hippocastanum growing in north-eastern Italy. Trees 17:367–375. https://doi.org/10.1007/s00468-003-0247-1 CrossRefGoogle Scholar
- Salmon Y, Torres-Ruiz JM, Poyatos R, Martinez-Vilalta J, Meir P, Cochard H, Mencuccini M (2015) Balancing the risks of hydraulic failure and carbon starvation: a twig scale analysis in declining Scots pine. Plant Cell Environ 38:2575–2588. https://doi.org/10.1111/pce.12572 CrossRefPubMedPubMedCentralGoogle Scholar
- Salomón RL, Limousin J-M, Ourcival J-M, Rodríguez-Calcerrada J, Steppe K (2017) Stem hydraulic capacitance decreases with drought stress: implications for modelling tree hydraulics in the Mediterranean oak Quercus ilex. Plant Cell Environ 40:1379–1391. https://doi.org/10.1111/pce.12928 CrossRefPubMedGoogle Scholar
- Scherrer B (2007) Biostatistique, 2e edn. Gaetan Morin, MontréalGoogle Scholar