Influence of tree species richness on tree growth and intrinsic water-use efficiency after drought in tree plantations in north-eastern Italy

Climate variability can exert a powerful impact on biotic competition, but past studies have focused largely on short-lived species, with a lack of attention to long-lived species such as trees. Therefore, there is a need to evaluate how competition regulates the climate-growth relationship in mature trees. We sampled the dominant tree species, Picea wilsonii Mast., on Xinglong Mountain, China, and studied the above issues by analyzing the relationship between tree radial growth, precipitation, and competition. In relatively wet years (precipitation > average), there was no significant difference in climate sensitivity between different competition classes. However, trees suffering from highly competitive stress were more sensitive to climate variability in all years, and particularly in the subset of years that was relatively drought (precipitation < average). These results suggest that competition enhances its ability to regulate tree growth response to climate variability in adverse weather conditions. Competition for resources between trees was asymmetrical, and an increase in height could give trees a disproportionate benefit. Thus, at trunk-level, both basal area incremental growth and intrinsic water-use efficiency of trees subjected to low competitive stress were significantly higher than trees that are subjected to highly competitive stress. Although the intrinsic water-use efficiency of trees under highly competitive stress increased more rapidly as the drought level increases, this did not change the fact that the radial growth of them declined more. Our research is valuable for the development of individual-tree growth models and advances our understanding for forest management under global climate change.

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Disentangling Contributions of CO2 Concentration and Climate to Changes in Intrinsic Water-Use Efficiency in the Arid Boreal Forest in China’s Altay Mountains

Forests ◽

10.3390/f9100642 ◽

2018 ◽

Vol 9 (10) ◽

pp. 642 ◽

Cited By ~ 9

Author(s):

Guobao Xu ◽

Xiaohong Liu ◽

Soumaya Belmecheri ◽

Tuo Chen ◽

Guoju Wu ◽

...

Keyword(s):

Boreal Forest ◽

Water Use Efficiency ◽

Water Use ◽

Tree Growth ◽

Co2 Concentration ◽

Optimization Approach ◽

The Past ◽

Altay Mountains ◽

Intrinsic Water Use Efficiency ◽

Use Efficiency

Intrinsic water-use efficiency (iWUE) is affected by the balance of photosynthetic rate, stomatal conductance, and climate, along with many other exogenous factors, such as the CO2 concentration in the atmosphere (CO2atm), nutrients, and water holding capacity of the soil. The relative contributions of CO2atm and climate to iWUE are still incompletely understood, particularly for boreal forests where the climate is undergoing unprecedented warming. We combined δ13C and δ18O in tree rings from the Siberian larch (Larix sibirica Ledeb.) in Northwestern China’s Altay Mountains, which receives 190 mm in annual precipitation, to detect the drivers of long-term iWUE changes and their time-varying contributions over the past 222 years. A climate optimization approach was used to isolate the influence of climate from CO2atm influence on iWUE. We found that iWUE increased about 33.6% from 1790 to 2011, and rising CO2atm contributed 48.8% to this iWUE increase. The contributions of CO2atm and climate (drought conditions) varied during the study period 1790–2011. From 1790 to 1876, the climate was the most important factor contributing to the changes in iWUE. From 1877 to 1972, CO2atm was the main contributor; however, after 1973, the climate was again the dominant contributor to the increase in iWUE, especially during 1996–2011. During the period 1996–2011, climate substantially (83%) contributed to the iWUE increase. Our findings imply that, in the boreal forest in Northwestern China’s arid region, iWUE experienced three changes: (1) the climate dominating from 1790 to 1876; (2) CO2atm dominating from 1877 to 1972, and (3) climate dominating again during the past four decades. We observed that the relationships between iWUE and tree-ring width shifted from positive to negative from 1996 onwards. These relationship changes indicate that CO2atm-mediated effects of increasing iWUE on tree growth are counteracted by climatic drought stress and iWUE increase cannot counter the stress from drought on tree growth in China’s arid boreal forest.

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Species-specific tree growth and intrinsic water-use efficiency of Dahurian larch ( Larix gmelinii ) and Mongolian pine ( Pinus sylvestris var. mongolica ) growing in a boreal permafrost region of the Greater Hinggan Mountains, Northeastern China

Agricultural and Forest Meteorology ◽

10.1016/j.agrformet.2017.09.013 ◽

2018 ◽

Vol 248 ◽

pp. 145-155 ◽

Cited By ~ 21

Author(s):

Xuanwen Zhang ◽

Xiaohong Liu ◽

Qiuliang Zhang ◽

Xiaomin Zeng ◽

Guobao Xu ◽

...

Keyword(s):

Pinus Sylvestris ◽

Water Use Efficiency ◽

Water Use ◽

Tree Growth ◽

Northeastern China ◽

Permafrost Region ◽

Dahurian Larch ◽

Intrinsic Water Use Efficiency ◽

Use Efficiency ◽

Species Specific

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Responses of Intrinsic Water-use Efficiency and Tree Growth to Climate Change in Semi-Arid Areas of North China

Scientific Reports ◽

10.1038/s41598-017-18694-z ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 12

Author(s):

L. U. Weiwei ◽

Y. U. Xinxiao ◽

J. I. A. Guodong ◽

L. I. Hanzhi ◽

L. I. U. Ziqiang

Keyword(s):

Climate Change ◽

Water Use Efficiency ◽

Water Use ◽

Tree Growth ◽

North China ◽

Arid Areas ◽

Intrinsic Water Use Efficiency ◽

Use Efficiency ◽

Semi Arid

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Cross-scale interactions affect tree growth and intrinsic water use efficiency and highlight the importance of spatial context in managing forests under global change

Journal of Ecology ◽

10.1111/1365-2745.12749 ◽

2017 ◽

Vol 105 (5) ◽

pp. 1425-1436 ◽

Cited By ~ 3

Author(s):

Kenneth J. Ruzicka ◽

Klaus J. Puettmann ◽

J. Renée Brooks

Keyword(s):

Global Change ◽

Water Use Efficiency ◽

Water Use ◽

Tree Growth ◽

Spatial Context ◽

Scale Interactions ◽

Intrinsic Water Use Efficiency ◽

Use Efficiency

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Overlapping Water and Nutrient Use Efficiencies and Carbon Assimilation between Coexisting Simple- and Compound-Leaved Trees from a Valley Savanna

Water ◽

10.3390/w12113037 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3037

Author(s):

Yang-Si-Ding Wang ◽

Da Yang ◽

Huai-Dong Wu ◽

Yun-Bing Zhang ◽

Shu-Bin Zhang ◽

...

Keyword(s):

Climate Change ◽

Water Use Efficiency ◽

Water Use ◽

Functional Traits ◽

Tree Species ◽

Carbon Assimilation ◽

Similar Response ◽

Nutrient Use ◽

Intrinsic Water Use Efficiency ◽

Use Efficiency

Identifying differences in ecophysiology between simple and compound leaves can help understand the adaptive significance of the compound leaf form and its response to climate change. However, we still know surprisingly little about differences in water and nutrient use, and photosynthetic capacity between co-occurring compound-leaved and simple-leaved tree species, especially in savanna ecosystems with dry-hot climate conditions. From July to September in 2015, we investigated 16 functional traits associated with water use, nutrients, and photosynthesis of six deciduous tree species (three simple-leaved and three compound-leaved species) coexisting in a valley-savanna in Southwest China. Our major objective was to test the variation in these functional traits between these two leaf forms. Overall, overlapping leaf mass per area (LMA), photosynthesis, as well as leaf nitrogen and phosphorus concentrations were found between these coexisting valley-savanna simple- and compound-leaved tree species. We didn’t find significant differences in water and photosynthetic nitrogen or phosphorus use efficiency between simple and compound leaves. Across these simple- and compound-leaved tree species, photosynthetic phosphorus use efficiencies were positively related to LMA and negatively correlated with phosphorus concentration per mass or area. Water use efficiency (intrinsic water use efficiency or stable carbon isotopic composition) was independent of all leaf traits. Similar ecophysiology strategies among these coexisting valley-savanna simple- and compound-leaved species suggested a convergence in ecological adaptation to the hot and dry environment. The overlap in traits related to water use, carbon assimilation, and stress tolerance (e.g., LMA) also suggests a similar response of these two leaf forms to a hotter and drier future due to the climate change.

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