TY - JOUR
T1 - Long-Term Monitoring of Tree Population Dynamics in Desert Ecosystems
T2 - Integrating Field and Satellite Data
AU - Isaacson, Sivan
AU - Ephrath, Jhonathan E.
AU - Rachmilevitch, Shimon
AU - Blumberg, Dan G.
AU - Shalmon, Benny
AU - Katz, Ofir
AU - Maman, Shimrit
N1 - Funding Information:
This research was funded by the Israel Ministry of Science and Technology. S.I. was supported by the Negev-Zin Scholarship and the Yair Guron Memorial Scholarship.
Publisher Copyright:
© 2023 by the authors.
PY - 2023/8/1
Y1 - 2023/8/1
N2 - Arid environments are characterized by rare rain events that are highly variable, as a result of which plant populations often exhibit episodic recruitment and mortality dynamics. However, direct records and observations of such events are rare because of the slow development of woody species. In this study, we described how a decrease in annual precipitation affected acacia tree population dynamics in two hydrological regime types: small wadis and salt flats. This study combines 15 years of continuous, yearly field monitoring of individual acacia trees and data from a historical Corona satellite image, which has extended the time scope of the research. Results indicate that the annual mortality of acacia trees in small wadis reflects the cumulative effective rain events in the preceding five years, whereas the population on the salt flats was not affected by annual rainfall fluctuations. Moreover, in small wadis, rain events of less than 8 mm did not increase acacia tree survival rates. The mortality pattern and dynamics of each plot was unique, suggesting unsynchronized mortality and recruitment episodes on a regional scale. Mortality in all plots was documented both in “old” trees (i.e., recognized in 1968) and “new” trees (not recognized in 1968), but varied highly between plots. More than 50% of the dead trees recorded at the sites had died during the previous dry period (2000–2010). Combining field monitoring and historical satellite image data provided a unique database of acacia population dynamics. This record revealed the response of the acacia population to climate fluctuations and a period of episodic mortality.
AB - Arid environments are characterized by rare rain events that are highly variable, as a result of which plant populations often exhibit episodic recruitment and mortality dynamics. However, direct records and observations of such events are rare because of the slow development of woody species. In this study, we described how a decrease in annual precipitation affected acacia tree population dynamics in two hydrological regime types: small wadis and salt flats. This study combines 15 years of continuous, yearly field monitoring of individual acacia trees and data from a historical Corona satellite image, which has extended the time scope of the research. Results indicate that the annual mortality of acacia trees in small wadis reflects the cumulative effective rain events in the preceding five years, whereas the population on the salt flats was not affected by annual rainfall fluctuations. Moreover, in small wadis, rain events of less than 8 mm did not increase acacia tree survival rates. The mortality pattern and dynamics of each plot was unique, suggesting unsynchronized mortality and recruitment episodes on a regional scale. Mortality in all plots was documented both in “old” trees (i.e., recognized in 1968) and “new” trees (not recognized in 1968), but varied highly between plots. More than 50% of the dead trees recorded at the sites had died during the previous dry period (2000–2010). Combining field monitoring and historical satellite image data provided a unique database of acacia population dynamics. This record revealed the response of the acacia population to climate fluctuations and a period of episodic mortality.
KW - acacia
KW - climate fluctuations
KW - hyper arid
KW - remote sensing
KW - trees episodic mortality
UR - http://www.scopus.com/inward/record.url?scp=85168855554&partnerID=8YFLogxK
U2 - 10.3390/land12081640
DO - 10.3390/land12081640
M3 - Article
AN - SCOPUS:85168855554
SN - 2073-445X
VL - 12
JO - Land
JF - Land
IS - 8
M1 - 1640
ER -