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Ramsay, Paul M.; Oxley, E. R. B.

doi:10.1023/a:1009796224479

Cited by 115 publications

(49 citation statements)

References 29 publications

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“…This high responsiveness results from the combined effect of the relatively uniform distribution of precipitation year-round -common in tropical regions -and the unique properties of the Histosol soils or Andean wetlands located near the streams. The high storage capacity of wetlands was also highlighted by Roa-García and Weiler (2010) after the comparison of three paired catchments in the growing coffee region of Colombia at lower elevations (2000-2200 m a.s.l.). Similarly, Histosol soils in our study site are rich in organic matter content (mean 86 % by volume), allowing for high water storage capacity.…”

Section: General Hydrometric and Isotopic Characterizationmentioning

confidence: 88%

“…grow primarily in Histosols, while tussock grass (mainly Calamagrostis sp.) (Ramsay and Oxley, 1997 Figure 1. Location of the study area, and the isotopic monitoring stations in the Zhurucay observatory for streamflow (M) and precipitation (P ).…”

Section: Study Sitementioning

confidence: 99%

“…Despite the importance of tropical biomes as natural sources and regulators of streamflow, there are very few studies of MTT in tropical environments (e.g., Farrick and Branfireun, 2015;Muñoz-Villers et al, 2016;Roa-García and Weiler, 2010;Timbe et al, 2014). The majority of MTT studies have been conducted in catchments with strong climate seasonality, i.e., located in the Northern and Southern hemispheres (e.g., Lyon et al, 2010;McGlynn and McDonnell, 2003;McGuire et al, 2005), and considerably less attention has been devoted to tropical environments.…”

Section: Introductionmentioning

confidence: 99%

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Insights into the water mean transit time in a high-elevation tropical ecosystem

Mosquera

Segura

Vaché

et al. 2016

Hydrol. Earth Syst. Sci.

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Abstract. This study focuses on the investigation of the mean transit time (MTT) of water and its spatial variability in a tropical high-elevation ecosystem (wet Andean páramo). The study site is the Zhurucay River Ecohydrological Observatory (7.53 km 2 ) located in southern Ecuador. A lumped parameter model considering five transit time distribution (TTD) functions was used to estimate MTTs under steadystate conditions (i.e., baseflow MTT). We used a unique data set of the δ 18 O isotopic composition of rainfall and streamflow water samples collected for 3 years (May 2011 to May 2014) in a nested monitoring system of streams. Linear regression between MTT and landscape (soil and vegetation cover, geology, and topography) and hydrometric (runoff coefficient and specific discharge rates) variables was used to explore controls on MTT variability, as well as mean electrical conductivity (MEC) as a possible proxy for MTT. Results revealed that the exponential TTD function best describes the hydrology of the site, indicating a relatively simple transition from rainfall water to the streams through the organic horizon of the wet páramo soils. MTT of the streams is relatively short (0.15-0.73 years, 53-264 days). Regression analysis revealed a negative correlation between the catchment's average slope and MTT (R 2 = 0.78, p < 0.05). MTT showed no significant correlation with hydrometric variables, whereas MEC increases with MTT (R 2 = 0.89, p < 0.001). Overall, we conclude that (1) baseflow MTT confirms that the hydrology of the ecosystem is dominated by shallow subsurface flow; (2) the interplay between the high storage capacity of the wet páramo soils and the slope of the catchments provides the ecosystem with high regulation capacity; and (3) MEC is an efficient predictor of MTT variability in this system of catchments with relatively homogeneous geology.

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Section: General Hydrometric and Isotopic Characterizationmentioning

confidence: 88%

Section: Study Sitementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Insights into the water mean transit time in a high-elevation tropical ecosystem

Mosquera

Segura

Vaché

et al. 2016

Hydrol. Earth Syst. Sci.

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“…Though intraspecific facilitation within cushion populations and between ramets of cushions has not been tested explicitly so far, it is highly probable that their structure, often composed of a large number of small rosettes (ramets) generating a compact cover [36], determines intense interactions between neighbouring rosettes, both positive and negative. Tussock grasses are frequently observed and often are a dominant life form in TAE [36,56,57]. There, tussock grasses display a typical twophase structure with tussocks having a limited lateral growth and a high density of tall stems at tussock centre (figure 1).…”

Section: Reference Vegetation Patterns and Parameter Assessmentmentioning

confidence: 99%

Plant clonal morphologies and spatial patterns as self-organized responses to resource-limited environments

Couteron

Anthelme

Clerc

et al. 2014

Phil. Trans. R. Soc. A.

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We propose here to interpret and model peculiar plant morphologies (cushions and tussocks) observed in the Andean Altiplano as localized structures. Such structures resulting in a patchy, aperiodic aspect of the vegetation cover are hypothesized to self-organize thanks to the interplay between facilitation and competition processes occurring at the scale of basic plant components biologically referred to as ‘ramets’. (Ramets are often of clonal origin.) To verify this interpretation, we applied a simple, fairly generic model (one integro-differential equation) emphasizing via Gaussian kernels non-local facilitative and competitive feedbacks of the vegetation biomass density on its own dynamics. We show that under realistic assumptions and parameter values relating to ramet scale, the model can reproduce some macroscopic features of the observed systems of patches and predict values for the inter-patch distance that match the distances encountered in the reference area (Sajama National Park in Bolivia). Prediction of the model can be confronted in the future with data on vegetation patterns along environmental gradients so as to anticipate the possible effect of global change on those vegetation systems experiencing constraining environmental conditions.

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“…Thus, species lists for sequential subplots of 1, 2, 3, 4, 6, 8, 9, 12, and 16 contiguous basic sampling units, ranging from 0.0625 m 2 to 1.0 m 2 , were well prepared for further analyses in this study. Ramsay and Oxley (1997) proposed a growth form classification for ten forms found within grassland communities: stem rosettes, basal rosettes, tussocks, acaulescent rosettes, cushions and mats, upright shrubs, prostrate shrubs, erect herbs, prostrate herbs, and trailing herbs. A quantitative determination of plant composition is important to better understand both community structure and ecosystem functions.…”

Section: Field Surveymentioning

confidence: 99%

Species-area relationship within and across functional groups at alpine grasslands on the northern Tibetan Plateau, China

Zhou

Shen

et al. 2016

J. Mt. Sci.

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Untitled

Cited by 115 publications

References 29 publications

Insights into the water mean transit time in a high-elevation tropical ecosystem

Insights into the water mean transit time in a high-elevation tropical ecosystem

Plant clonal morphologies and spatial patterns as self-organized responses to resource-limited environments

Species-area relationship within and across functional groups at alpine grasslands on the northern Tibetan Plateau, China

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