Tree-climate relations along an elevational transect in Manang Valley, central Nepal
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Tree-climate relations along an elevational transect in Manang Valley, central Nepal. / Kharal, Deepak Kumar; Thapa, Udya K.; St. George, Scott; Meilby, Henrik; Rayamajhi, Santosh; Bhuju, Dinesh R.
I: Dendrochronologia, Bind 41, 2017, s. 57-64.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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T1 - Tree-climate relations along an elevational transect in Manang Valley, central Nepal
AU - Kharal, Deepak Kumar
AU - Thapa, Udya K.
AU - St. George, Scott
AU - Meilby, Henrik
AU - Rayamajhi, Santosh
AU - Bhuju, Dinesh R.
PY - 2017
Y1 - 2017
N2 - Elevation is a strong determinant of local climate and may therefore be an important factor to consider when examining the association between climate and tree growth. In this study, we developed a set of tree-ring width records for Abies spectablis (D.Don Spach) in the Manang Valley of central Nepal Himalaya and tested how tree growth and the relationship between tree growth and climate varied across a 450-m elevation transect. The sampled trees had a median age of 115 years, and the oldest individual specimen, which was located at 3775 m, had more than 212 rings. The common signal shared across the tree-ring series was relatively weak, which is typical for ring-width chronologies from the Himalayas. Even though these forests are located within a semi-arid climate, temperature had a stronger and more consistent influence on Abies growth than precipitation. All three chronologies across the transect exhibited a negative relationship with mean March–June temperatures, which could reflect the impact of warm weather during the early part of the growing season, possibly mediated through its influence on evapotranspiration and soil moisture. While interannual fluctuations in tree growth were synchronous across sites, longer-term trends in growth varied across the transect, with high-elevation trees showing elevated growth during the last two or three decades and lower-elevation trees behaving just the opposite. These disparate trends suggest the factors that control longer-term trends in forest productivity vary substantially with elevation. For studies intending to use tree-ring width records in the Trans Himalaya as climate proxies, it may be preferable to collect specimens at lower forest sites, where the agreement across the population of trees is stronger. Because longer-term trends in ring width can differ substantially from one elevation to another in this region, it may also be necessary to collect a greater number of samples from several positions along an elevation gradient.
AB - Elevation is a strong determinant of local climate and may therefore be an important factor to consider when examining the association between climate and tree growth. In this study, we developed a set of tree-ring width records for Abies spectablis (D.Don Spach) in the Manang Valley of central Nepal Himalaya and tested how tree growth and the relationship between tree growth and climate varied across a 450-m elevation transect. The sampled trees had a median age of 115 years, and the oldest individual specimen, which was located at 3775 m, had more than 212 rings. The common signal shared across the tree-ring series was relatively weak, which is typical for ring-width chronologies from the Himalayas. Even though these forests are located within a semi-arid climate, temperature had a stronger and more consistent influence on Abies growth than precipitation. All three chronologies across the transect exhibited a negative relationship with mean March–June temperatures, which could reflect the impact of warm weather during the early part of the growing season, possibly mediated through its influence on evapotranspiration and soil moisture. While interannual fluctuations in tree growth were synchronous across sites, longer-term trends in growth varied across the transect, with high-elevation trees showing elevated growth during the last two or three decades and lower-elevation trees behaving just the opposite. These disparate trends suggest the factors that control longer-term trends in forest productivity vary substantially with elevation. For studies intending to use tree-ring width records in the Trans Himalaya as climate proxies, it may be preferable to collect specimens at lower forest sites, where the agreement across the population of trees is stronger. Because longer-term trends in ring width can differ substantially from one elevation to another in this region, it may also be necessary to collect a greater number of samples from several positions along an elevation gradient.
KW - Abies spectabilis
KW - Central Himalaya
KW - Elevation transect
KW - Nepal
KW - Tree-climate relations
U2 - 10.1016/j.dendro.2016.04.004
DO - 10.1016/j.dendro.2016.04.004
M3 - Journal article
AN - SCOPUS:84964849900
VL - 41
SP - 57
EP - 64
JO - Dendrochronologia
JF - Dendrochronologia
SN - 1125-7865
ER -
ID: 178488253