Vegetation analysis in the coastal dune ecosystem of the Western Egyptian Desert

1981 ◽  
Vol 16 (3) ◽  
pp. 293-308 ◽  
Author(s):  
M. E. Scholten ◽  
M. W. A. C. Hukkelhoven ◽  
M. A. Ayyad ◽  
M. J. A. Werger

PLoS ONE ◽  
2015 ◽  
Vol 10 (2) ◽  
pp. e0117903 ◽  
Author(s):  
Matthew D. Johnson ◽  
Yesenia L. De León


Ecohydrology ◽  
2013 ◽  
Vol 7 (2) ◽  
pp. 783-793 ◽  
Author(s):  
M. Paz Esquivias ◽  
María Zunzunegui ◽  
Mari Cruz Díaz Barradas ◽  
Leonor Álvarez-Cansino


2017 ◽  
Vol 22 (2) ◽  
pp. 53-60
Author(s):  
Yasutaka Nakata ◽  
Hajime Matsushima ◽  
Yoshihiko Hirabuki ◽  
Dai Nagamatsu ◽  
Kohei Oka ◽  
...  


2009 ◽  
Vol 6 (11) ◽  
pp. 2599-2610 ◽  
Author(s):  
S. Mereu ◽  
E. Salvatori ◽  
L. Fusaro ◽  
G. Gerosa ◽  
B. Muys ◽  
...  

Abstract. An integrated approach has been used to analyse the dependence of three Mediterranean species, A. unedo L., Q. ilex L., and P. latifolia L. co-occurring in a coastal dune ecosystem on two different water resources: groundwater and rainfed upper soil layers. The approach included leaf level gas exchanges, sap flow measurements and structural adaptations between 15 May and 31 July 2007. During this period it was possible to capture different species-specific response patterns to an environment characterized by a sandy soil, with a low water retention capacity, and the presence of a water table. The latter did not completely prevent the development of a drought response and, combined with previous studies in the same area, response differences between species have been partially attributed to different root distributions. Sap flow of A. unedo decreased rapidly with the decline of soil water content, while that of Q. ilex decreased only moderately. Midday leaf water potential of P. latifolia and A. unedo ranged between −2.2 and −2.7 MPa throughout the measuring period, while in Q. ilex it decreased down to −3.4 MPa at the end of the season. A. unedo was the only species that responded to drought with a decrease of its leaf area to sapwood area ratio from 23.9±1.2 (May) to 15.2±1.5 (July). While A. unedo also underwent an almost stepwise loss on hydraulic conductivity, such a loss did not occur for Q. ilex, whereas P. latifolia was able to slightly increase its hydraulic conducitivity. These differences show how different plant compartments coordinate differently between species in their responses to drought. The different responses appear to be mediated by different root distributions of the species and their relative resistances to drought are likely to depend on the duration of the periods in which water remains extractable in the upper soil layers.



2009 ◽  
Vol 6 (1) ◽  
pp. 1713-1746 ◽  
Author(s):  
S. Mereu ◽  
E. Salvatori ◽  
L. Fusaro ◽  
G. Gerosa ◽  
B. Muys ◽  
...  

Abstract. An integrated approach has been used to analyse the water relations of three Mediterranean species, A. unedo L., Q. ilex L. and P. latifolia L. co-occurring in a coastal dune ecosystem. The approach considered leaf level gas exchange, sap flow measurements and structural adaptations between 15 May and 31 July 2007, and was necessary to capture the different response of the three species to the same environment. The complexity of the response was proportional to the complexity of the system, characterized by a sandy soil with a low water retention capacity and the presence of a water table. The latter did not completely prevent the development of a drought response, and species differences in this responses have been partially attributed to a different root distribution. Sap flow of A. unedo decreased rapidly in response to the decline of Soil Water Content, while that of Q. ilex decreased only moderately. Midday leaf water potential of P. latifolia and A. unedo was between 2.2 and 2.7 MPa through the measuring period, while in Q. ilex it reached a value of 3.4 MPa at the end of the season. A. unedo was the only species to decrease the leaf area to sapwood area ratio from 23.9±1.2 (May) to 15.2±1.5 (July), as a response to drought. A. unedo also underwent an almost stepwise loss on hydraulic conductivity, such a loss didn't occur for Q. ilex, while P. latifolia was able to slightly increase hydraulic conductivity, showing how different plant compartments coordinate differently between species as a response to drought. Such different coordination affects the gas exchange between vegetation and the atmosphere, and has implications for the response of the Mediterranean coastal dune ecosystems to climate change.



Ecology ◽  
2010 ◽  
Vol 91 (4) ◽  
pp. 1237-1243 ◽  
Author(s):  
Gregory M. Crutsinger ◽  
Sharon Y. Strauss ◽  
Jennifer A. Rudgers


2008 ◽  
Vol 40 (2) ◽  
pp. 210-217 ◽  
Author(s):  
Elizabete Marchante ◽  
Annelise Kjøller ◽  
Sten Struwe ◽  
Helena Freitas




2021 ◽  
Vol 13 (3) ◽  
pp. 354
Author(s):  
Zach Hilgendorf ◽  
M. Colin Marvin ◽  
Craig M. Turner ◽  
Ian J. Walker

Uncrewed aerial systems (UAS) provide an effective method to examine geomorphic and vegetation change in restored coastal dune ecosystems. Coupling structure-from-motion (SfM) photogrammetry with RGB orthomosaic imagery allows researchers to characterize spatial-temporal geomorphic responses associated with differences in vegetation cover. Such approaches provide quantitative data on landscape morphodynamics and sediment erosion and deposition responses that allow scientists and land managers to assess the efficacy of dynamic restoration efforts and, in turn, make informed decisions for future restoration projects. Two different restored coastal foredune sites in Humboldt County, California were monitored between 2016–20 with UAS (quadcopter and fixed-wing), kite aerial photogrammetry (KAP), and terrestrial laser scanning (TLS) platforms. We compared our KAP- and UAS-SfM elevation models to concurrently collected TLS bare earth models for five of our fifteen collections. The goal of this study was to inform on the potential of a multi-platform aerial approach for calculating geomorphic differences (i.e., topographic differencing), in order to quantify sediment erosion and deposition, and vegetation change over a coastal dune ecosystem. While UAS-SfM datasets were relatively well fit to their TLS counterparts (2.1–12.2% area of difference), the KAP-SfM surfaces exhibited higher deviations (23.6–27.6%) and suffered from systematic collection inconsistencies related to methods and susceptibility to external factors (e.g., the influence of wind speed and direction on variable altitude, image overlap, and coverage extent). Finally, we provide commentary on the logistical considerations regarding KAP and UAS data collection and the construction of uncertainty budgets for geomorphic change detection (GCD), while providing suggestions for standardizing methods for uncertainty budgeting. While we propose an approach that incorporates multiple levels of collection- and processing-based uncertainty, we also recognize that uncertainty is often project-specific and outline the development of potential standards for incorporating uncertainty budgets in SfM projects.



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