Climate control on ring width and intra-annual density fluctuations in Pinus kesiya growing in a sub-tropical forest of Manipur, Northeast India

Abstract

Key message Growth ring study of Pinus kesiya (khasi pine) growing in sub-tropical forest in Manipur, northeast India was performed to understand climate signatures in ring widths and intra-annual density fluctuations. Abstract The growth rings in khasi pine (Pinus kesiya Royle ex Gordon) growing in sub-tropical Reserve Forest in Imphal, Manipur, northeast India were analysed to understand environmental signals present in ring-width series and intra-annual density fluctuations (IADFs). For this the growth ring sequences in increment core samples collected from 28 trees were precisely dated and a ringwidth chronology spanning AD 1958-2014 developed. The correlation analyses between ring-width chronology and weather data of Imphal revealed that a cool AprilMay-June favour tree growth. The wood anatomical features of growth rings revealed the occurrence of IADFs in early-and latewoods. The IADFs in earlywood were found to be associated with reduced precipitation in months from April to July. However, the wetter conditions in late growing season, especially August/September triggered the formation of IADFs in latewood. Our findings endorse that the IADF chronologies of khasi pine could emerge as an important proxy of summer monsoon rainfall in long-term perspective in data scarce region of northeast India.

Resistance, Recovery and Resilience of Two Co-Occurring Palaeotropical Pinus Species Differing in the Sizes of Their Distribution Areas

“…Our results of negative correlations of diameter increment with temperature in PIKE during the dry period in the hottest months of the year are in accordance with the results from studies of the same species conducted in northwestern Thailand [51] and northeastern India [52]. The negative correlation of tree growth with precipitation during the monsoon season in August, however, is in contrast to the results obtained by Pumijumnong and Wanyaphet [53] of a positive association of P. kesiya's diameter increment with precipitation during the monsoon period in September.…”

Response between tree-rings of Pinus kesiya and daily climate data – A study from Manipur, Northeast India

“…This station records monthly mean temperature and total monthly precipitation for 1955-2012 C.E. This dataset has been analyzed in Singh et al (2016) and showed that the station recorded June as the wettest month with total precipitation reaching over 256 mm. The months of May to September receive over 2/3rd of the annual precipitation (1400 mm) and considered as very humid season.…”

“…For its proper growth it requires moist conditions having an annual rainfall of 200 cm with well-drained soils, while extreme heat or cold conditions have a detrimental effect on the tree (Krishnamurthi, 1969). The tree-ring studies on this species have been carried out in India (Chaudhary & Bhattacharyya, 2002;Singh & Venugopal, 2011;Shah & Bhattacharyya, 2012;Singh et al, 2016, Upadhyay et al, 2019 and Thailand (Buckley et al, 1995;Pumijumnong & Wanyaphet, 2006;Pumijumnong & Eckstein, 2011). The dendrochronological importance of this species is well established and we further make an attempt to investigate its relationship with climate variations in the Manipur region.…”

“…These studies are mostly available from few geographical regions of Northeast India i.e., Arunachal Pradesh (Chaudhary & Bhattacharyya, 2000;Bhattacharyya & Chaudhary, 2003;Bhattacharyya et al, 2008;Shah et al, 2019), Sikkim and Darjeeling Himalaya (Bhattacharyya & Chaudhary, 2003;Shah et al, 2014a, Yadava et al, 2015Shah & Mehrotra, 2017;Borgaonkar et al, 2018), Meghalaya (Chaudhary & Bhattacharyya, 2002;Shah & Bhattacharyya, 2012) and Mizoram (Upadhyay et al, 2019). In addition, a single dendrochronological study is reported from the state of Manipur carried out by Singh et al (2016). In all these studies, monthly precipitation and temperature are used to derive their response on tree growth.…”

Editorial note for the special section on ‘Tree-Ring Research in Asia’ of TREES: structure and function

“…Singh et al (2016) are able to assign these features to short-term fluctuations in precipitation. While latewood IADFs are formed by earlywood-like tracheids with wide cell lumen formed during periods with excessive rainfall in the late growing season, earlywood IADFs are triggered by deficient moisture availability during the early growing season around May, after tree growth has been activated by precipitation in the pre-monsoon season in April.…”