Climate-growth Relationship of Pinus patula Schldl. et Cham. in Wondo Genet, South Central Ethiopia

Belay Tt

doi:10.4172/2332-2594.1000181

Abstract

Most tropical regions are facing historical difficulties of generating biologically reconstructed long-term climate records. Dendrochronology (tree-ring studies) is a powerful tool to develop high-resolution and exactly dated proxies for climate reconstruction. In particular, dendroclimatological research is important in understanding both spatial and temporal characteristics of climate influences on tree growth. This project investigated the relationship between climate (precipitation and temperature) and tree rings, and showed its potential for climate reconstruction. Owing to the seasonal variation in rainfall, we expected the formation of annual growth rings in the wood of the forest of Wondo Genet. The project also carried out annual ring assessment and described the basic anatomical features of growth ring boundaries of the species under study. Wood disc samples of 15 trees belonging to the species of Pinus patula in the study site served to develop climate sensitive ring-width chronologies using standard dendrochronological techniques. A tree ring chronology was developed for the study species, and this enabled the assessment of the existing relationship between climate and tree growth patterns. The relationship between annual and seasonal precipitation, and mean monthly maximum and minimum temperature and ring-width indices was performed by correlation and simple regression analyses. The study species showed significant relationships with the rainy season precipitation proving the existence of annual tree rings (r=0.42). Monthly correlation analysis also showed that rainfall during July had the highest positive and significant correlation with the growth of the study species (r=0.50). The results indicated that annual growth of the species is primarily influenced by water availability during the growing (rainy) season. The study generally infers that the presence of anatomically distinct annual growth rings and high-quality cross dating and climate-growth relationships make the study species useful candidate for dendrochronological studies.

Highlights

Background and JustificationsClimate change is of increasing concern to scientists because of its serious ramifications on ecosystems, in particular
Understanding the climate variable which is significantly related to the growth dynamics of the study species will enable to generate reliable information for the sustainable management of these species
This study looked into wood anatomy and growth responses of P. patula to climate variability at different temporal scales using standard dendrochronological techniques in Wondo Genet, South Central Ethiopia

Summary

Introduction

Background and JustificationsClimate change is of increasing concern to scientists because of its serious ramifications on ecosystems, in particular. To understand long-term impacts of climate change both in the past and in the future, it is necessary first to go beyond the time limit of instrumental records of climate. To this end, high resolution climate proxies are used to extend historical climate records back in time, providing a more comprehensive overview of trends in past climate [2,3]. High resolution climate proxies are used to extend historical climate records back in time, providing a more comprehensive overview of trends in past climate [2,3] Among these proxies that have the potential to express aspects of climate variability with perfect dating fidelity, at annual resolution, tree rings remain the most important and widely used sources of long-term proxy data [2]. Tree-ring records are exceptionally valuable proxy for paleo-environmental study because of the following factors: They provide continuous records with annual to seasonal resolution; the existence of large geographic-scale patterns of synchronic inter-annual variability; the increasing availability of extensive networks of tree-ring chronologies; and the possibility of using simple linear models of climate-growth relationships that can be verified and calibrated [7]

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