Geographic and temporal patterns in white spruce climate–growth relationships in Yukon, Canada

Abstract:The response of radial growth to climate and the climate sensitivity of tree growth at different ages in different drought conditions are essential for predicting forest dynamics and making correct forest management policies. In this study, we analyzed the growth responsiveness of Picea crassifolia Kom. to climate and explored the relationship between age and climate sensitivity of radial growth at the individual tree scale in the wetter eastern area and drier western area of the Qilian Mountains. Pearson correlation coefficients were calculated between the chronology of each tree and climatic factors to examine the climate-growth relationships. Linear fitting, quadratic polynomial fitting and exponential fitting were used to test the relationships between age and mean sensitivity, standard deviation and radial growth's response to climate. Trees in the wetter eastern area showed a weaker response to climate than those in the drier western area and were significantly correlated with precipitation and mean temperature in the previous and current mid-late summer. Trees in the drier western area were mainly limited by precipitation of the previous August, the current May and June, as well as limited by temperature in the previous and current early-middle summer. In the wetter area, the younger trees were more sensitive to both precipitation and temperature than the older trees. In the drier area, younger/older trees showed a stronger sensitivity to precipitation in the current August and September/May, whereas trees 120-140 years old showed a stronger correlation with temperature factors in the summer. It was determined that mature trees in the drier area were more strongly influenced by the climate, especially in the context of increasing temperature. These trees should be paid special attention in forest management.

Section: Introductionmentioning

confidence: 99%

Relationships between Tree Age and Climate Sensitivity of Radial Growth in Different Drought Conditions of Qilian Mountains, Northwestern China

Zhang

Jiang

Zhao

et al. 2018

“…Tree-ring records are often used to investigate the responses of tree growth to historical climate variations, to predict the effects of future climate change on tree growth, and to understand the spatial and temporal patterns of tree-growth variability of forest ecosystems [5][6][7]. Therefore, tree-ring records can increase our capacity to predict potential changes in forest structure and composition, as well as provide important information on natural resource management [8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Radial Growth Response of Larix gmelinii to Climate along a Latitudinal Gradient in the Greater Khingan Mountains, Northeastern China

Jiang

Zhang

Han

et al. 2016

Abstract:To explore how climatic factors influence tree growth within the context of global climate changes, we used a dendroclimatological analysis to understand the response of Larix gmelinii to climatic variations along a broad latitudinal gradient from 47.27 • to 52.66 • N in the Greater Khingan Mountains of Northeastern China. The growth-limiting climate factors and a detailed association between radial growth and climate were identified along the gradient using redundancy analysis (RDA) and standard correlation function analysis over the period 1960-2013. The results showed that temperatures during current June to July represented the most important factor affecting tree radial growth in the study area. Across all studied latitudes, Larix gmelinii growth might be decreasing in radial growth due to higher monthly maximum temperature (Tmax) and monthly mean temperatures (Tm) in the current June, especially for the stands at low and middle latitudes. With continued warming, Larix gmelinii radial growth at high latitudes (e.g., Mangui (MG) and Mohe (MH)) might be reduced by warmer temperatures in July. In addition, Larix gmelinii might be decreasing in radial growth from decreasing precipitation. Our results show that there is a decreasing trend in Larix gmelinii radial growth under the observed general increase of temperatures in the Greater Khingan Mountains in recent years.

“…Indeed, although long-term (1901-2015) mean values of precipitation as snow, growing degree days, climate moisture deficit and May-September precipitation differed between sites, there was a large amount of overlap in the annual values when considering interannual variability (Figure 2). Perhaps we did not find the site-specific variation that we expected in part because we compared our chronologies to site-specific climate data, unlike previous studies, which have compared growth to regional climate records (e.g., [16,19,24]). …”

Section: Discussionmentioning

confidence: 86%

“…This is in contrast to the many studies that have found considerable differences in climate sensitivity within individual species across large-scale (i.e., latitudinal or continental) climate gradients. For instance, climate responses have been shown to depend on environmental conditions that vary by latitude and elevation [53], to differ by climatic regime [16,19,24] and to differ by latitude [56]. In all, this suggests that the climatic differences among the sides of Mt.…”

Section: Discussionmentioning

confidence: 99%

“…Even though it is common for treeline to be dominated by more than one species, studies often focus on how climate sensitivity of an individual species varies across vast regions with different macroclimates [11,[16][17][18][19][20][21]. Studies like these have shown synchrony within a climatic zone and significant differences in influential climate variables and climate sensitivity across climatic zones [11,[16][17][18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

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Site- and Species-Specific Influences on Sub-Alpine Conifer Growth in Mt. Rainier National Park, USA

Legendre-Fixx

Anderegg

Ettinger

et al. 2017

Abstract:Identifying the factors that influence the climate sensitivity of treeline species is critical to understanding carbon sequestration, forest dynamics, and conservation in high elevation forest/meadow ecotones. Using tree cores from four sub-alpine conifer species collected from three sides of Mt. Rainier, WA, USA, we investigated the influences of species identity and sites with different local climates on radial growth-climate relationships. We created chronologies for each species at each site, determined influential plant-relevant annual and seasonal climatic variables influencing growth, and investigated how the strength of climate sensitivity varied across species and location. Overall, similar climate variables constrained growth on all three sides of the mountain for each of the four study species. Summer warmth positively influenced radial growth, whereas snow, spring warmth, previous summer warmth, and spring humidity negatively influenced growth. We discovered only a few subtle differences in the climate sensitivity of co-occurring species at the same site and between the same species at different sites in pairwise comparisons. A model including species by climate interactions provided the best balance between parsimony and fit, but did not lead to substantially greater predictive power relative to a model without site or species interactions. Our results imply that at treeline in moist temperate regions like Mt. Rainier, the same climatic variables drive annual variation in growth across species and locations, despite species differences in physiology and site differences in mean climates.