An Assessment of Aboveground Net Primary Productivity in Andean Grasslands of Central Ecuador

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

doi:10.1659/0276-4741(2001)021[0161:aaoanp]2.0.co;2

Cited by 26 publications

(18 citation statements)

References 14 publications

(16 reference statements)

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“…Regarding tussock grasses, there is not enough information about their growing and water consumption (Carrillo-Rojas et al, 2019), but their net primary productivity is low. In fact, tussock grasses net primary production is 168 g m −2 year −1 at 3,750 m a.s.l., (e.g., other grasses = 1,170 g m −2 year −1 ) in central Ecuador (Ramsay & Oxley, 2001 that is, there is a high SWC stability after the emulation. However, we have not found studies in páramo ecosystems that analyze the effects of extensive grazing in SWC dynamic, probably because earlier studies used punctual SWC data and not continuous.…”

Section: Soil Water Content After the Tussock Grasses Cutout: Post-supporting

confidence: 88%

“…In fact, tussock grasses net primary production is 168 g m −2 year −1 at 3,750 m a.s.l., (e.g., other grasses = 1,170 g m −2 year −1 ) in central Ecuador (Ramsay & Oxley, 2001 SWC was not extensively monitored or they did not take into account the hillslope characteristics at different soil profiles and depths (e.g., Mosquera et al, 2016). In fact, tussock grasses net primary production is 168 g m −2 year −1 at 3,750 m a.s.l., (e.g., other grasses = 1,170 g m −2 year −1 ) in central Ecuador (Ramsay & Oxley, 2001 SWC was not extensively monitored or they did not take into account the hillslope characteristics at different soil profiles and depths (e.g., Mosquera et al, 2016).…”

Section: Soil Water Content After the Tussock Grasses Cutout: Post-mentioning

confidence: 99%

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Impact of tussock grasses removal on soil water content dynamics of a tropical mountain hillslope

2019

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Land use impacts on soil water content (SWC) are scarcely studied in mountain humid ecosystems, such as the Andean páramos, despite its influence on ecohydrological processes. Our objective was to analyze the impacts of extensive grazing on SWC of an Andean páramo hillslope with native tussock grasses. Along two parallel transects in a hillslope, we monitored SWC through pairs of SWC sensors placed at different soil depths (Ah horizon= 10 -35 cm; C horizon= 65 -75 cm). The tussock grasses were cutout from one transect (Experimental) as an emulation of extensive grazing (without soil destruction), whereas the second transect (Control) remained intact.Both transects were hourly monitored for 10 months (post-intervention period).Post-intervention period was compared with a pre-intervention period of similar precipitation characteristics to minimize the influence of precipitation in the interpretation of the results. We analyzed both periods through differences in SWC between the pairs of sensors (Experimental minus Control) and differences in SWC dynamic of the pairs of sensors through linear regressions (slope and intercept values). Results suggest that the emulation did not change the mean SWC, but caused a reduction of SWC dynamic. Causes of SWC attenuation were a lower interception and transpiration, a higher amount of effective rainfall infiltrated, and similar evaporation from the soil than under unchanged conditions. These observations were done at all the soil depths. Probably, extensive grazing does not negatively affect the hydrological functioning of páramo ecosystems, particularly its water yield, as long as the soil remains undisturbed.

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Section: Soil Water Content After the Tussock Grasses Cutout: Post-supporting

confidence: 88%

Section: Soil Water Content After the Tussock Grasses Cutout: Post-mentioning

confidence: 99%

Impact of tussock grasses removal on soil water content dynamics of a tropical mountain hillslope

2019

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“…All plants were hand clipped at ground level. Following Ramsay and Oxley (), fixed dead material (i.e. dead leaves still attached to the tussocks, Waren et al .…”

Section: Methodsmentioning

confidence: 99%

“…(), above‐ground biomass estimations ranged from 205 g m −2 to 2829–3553 g m −2 , depending on the degree of grazing or burning and pools sampled, which translates into 1.0 to 14.1–17.8 Mg C ha −1 . Ramsay & Oxley () estimated standing biomass of 794 g m −2 and 837 g m −2 at two Ecuadorian páramo grassland sites, which translates to 4.0–4.2 Mg C ha −1 , and Gibbon et al . () estimated 6.5 Mg C ha −1 in their grazed Peruvian puna sites.…”

Section: Introductionmentioning

confidence: 98%

Grass allometry and estimation of above-ground biomass in tropical alpine tussock grasslands

et al. 2013

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The puna/páramo grasslands span across the highest altitudes of the tropical Andes, and their ecosystem dynamics are still poorly understood. In this study we examined the above-ground biomass and developed species specific and multispecies power-law allometric equations for four tussock grass species in Peruvian high altitude grasslands, considering maximum height (hmax), elliptical crown area and elliptical basal area. Although these predictors are commonly used among allometric literature, they have not previously been used for estimating puna grassland biomass. Total above-ground biomass was estimated to be of 6.7 ± 0.2 Mg ha −1 (3.35 ± 0.1 Mg C ha −1 ). All allometric relationships fitted to similar power-law models, with basal area and crown area as the most influential predictors, although the fit improved when tussock maximum height was included in the model. Multispecies allometries gave better fits than the other species-specific equations, but the best equation should be used depending on the species composition of the target grassland. These allometric equations provide an useful approach for measuring above-ground biomass and productivity in high-altitude Andean grasslands, where destructive sampling can be challenging and difficult because of the remoteness of the area. These equations can be also applicable for establishing above-ground reference levels before the adoption of carbon compensation mechanisms or grassland management policies, as well as for measuring the impact of land use changes in Andean ecosystems.

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“…to 4°C at 4,000 m.a.s.l.). The geobotanical background of both study areas is provided by Ramsay and Oxley (2001).…”

Section: Description Of the Study Sitesmentioning

confidence: 99%

Can isoprenoids in leaves and roots of plants serve as biomarkers for past vegetation changes? A case study from the Ecuadorian Andes

et al. 2007

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An Assessment of Aboveground Net Primary Productivity in Andean Grasslands of Central Ecuador

Abstract: BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Cited by 26 publications

References 14 publications

Impact of tussock grasses removal on soil water content dynamics of a tropical mountain hillslope

Impact of tussock grasses removal on soil water content dynamics of a tropical mountain hillslope

Grass allometry and estimation of above-ground biomass in tropical alpine tussock grasslands

Can isoprenoids in leaves and roots of plants serve as biomarkers for past vegetation changes? A case study from the Ecuadorian Andes

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