Tree rings as indicators of climatic variation in the Trans-Mexican Volcanic Belt, central Mexico
Por:
Carlon Allende, Teodoro, Villanueva Diaz, Jose, Soto Castro, Gisela, Mendoza, Manuel E., Luis Macias, Jose
Publicada:
1 ene 2021
Resumen:
How tree growth responds to climate is determined by temperature and
water availability, but climate change is causing shifts in forest
growth that could be evaluated through tree-ring growth studies given
that it is annual radial increase is influenced by interannual and
multiannual climatic variations. We evaluated the influence of
oceanic-atmospheric indices and the climate response on the annual
radial increase of Pinus hartwegii Lindl. A total of 140 increment cores
were obtained from 82 selected P. hartwegii specimens growing at the
treeline of the Tancitaro stratovolcano, Michoacan, Mexico to develop a
348-year long ring-width chronology. Correlation and response function
analyses were carried out between the tree-ring series and monthly
climate records and by subperiods of 50 yrs. Climate records were
obtained from six weather stations near the study site and
oceanic-atmospheric indices were downloaded from international climatic
sources. The chronology was related to drought indices involving
precipitation, temperature, evaporation, and soil water content. The
results indicated that accumulated precipitation from February to April,
and the mean and minimum temperature from March to May and from
September to November of the current growth year, had a positive
correlation with the P. hartwegii ring-width chronology. The maximum
temperature of March and May of the current growth year produced a
negative correlation and in November positive correlation. The analysis
of the response function indicated that P. hartwegii had a negative
growth response to the average and maximum temperature of March. The
analysis of the response function in 50-year subperiods indicated a
stable response in precipitation from February to April of the period
1925 to 2000. However, when the temperature increased, the stability of
the growth response became negative, mainly due to an increase in
temperature in combination with low precipitation volumes, which usually
occurs from March to May. The association between the ring-width series,
and indices of ENSO (MEI, El Nino 4) showed a significant positive
correlation, but negative with SOI. Similarly, the relationship with the
PDO was positive, but negative with AMO. The association with drought
indices (PDSI + JJA, PDSI*, SPEI) was positive and significant. We
conclude that the populations of P. hartwegii of the Tancitaro
stratovolcano constitute an ecological indicator of long-term
precipitation and temperature variability and is a high-resolution proxy
for regional rainfall reconstruction at least for the last three
centuries.
Filiaciones:
Univ Nacl Autonoma Mexico, CONACYT Inst Geofis, Unidad Michoacan, Antigua Carretera Patzcuaro 8701, Morelia 58190, Michoacan, Mexico
Inst Nacl Invest Forestales Agr & Pecuarias, Km 6-5 Margen Derecha Canal Sacramento, Durango 35140, Mexico
Inst Tecnol Valle Morelia, Morelia Salamanca Km 6-5, Morelia, Michoacan, Mexico
Univ Nacl Autonoma Mexico, Ctr Invest Geog Ambiental, Antigua Carretera Patzcuaro 8701, Morelia 58190, Michoacan, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Unidad Michoacan, Antigua Carretera Patzcuaro 8701, Morelia 58190, Michoacan, Mexico
|