Effects of Seasonal Rest in Aboveground Biomass for a Native Grassland of the Flood Pampa, Argentina

Hidalgo, L.G.; Cauhépé, M. A.

doi:10.2307/4002747

Cited by 15 publications

(10 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, in this system, accumulation of P reserves during nutrient Xuxes likely represents an ecological advantage when considering frequent defoliation by herbivores. S. indicus is considered a grazingtolerant species since it is the only grass species increasing its importance under grazing (Hidalgo and Cauhépé 1991). Its response to increases in soil P availability may be one factor responsible for this tolerance to grazing.…”

Section: Speciesmentioning

confidence: 99%

Phosphorus reserves increase grass regrowth after defoliation

Oyarzábal

Oesterheld

2009

Oecologia

View full text Add to dashboard Cite

Accumulation of P above levels that promote growth, a common plant response called "luxury consumption", can be considered as a form of reserve to support future growth when the nutrient can subsequently be mobilized. However, the effect of P reserves on regrowth following defoliation has not been demonstrated. We tested the hypothesis that P luxury consumption increases plant tolerance to defoliation. We performed two experiments with four grass species from a continuously grazed temperate grassland in the Flooding Pampa (Argentina). The first experiment, aimed at generating P luxury consumption by fertilization, resulted in one species (Sporobolus indicus) showing luxury consumption. In this way, we were able to obtain plants of S. indicus with similar biomass but contrasting amounts of P reserves. The second experiment evaluated the subsequent regrowth following defoliation on a P-free medium of these plants differing in P reserves. Regrowth was larger for plants that had shown P luxury consumption during a previous period than for plants with lower levels of P reserves. During regrowth these plants showed a clear pattern of P remobilization from the stubble, crown, and root compartments to the regrowing tissue, in addition to a likely reutilization of P present in leaf-growth zones. This work is the first showing that high levels of P reserves can confer tolerance to defoliation by promoting compensatory growth under P deficiency.

show abstract

Section: Speciesmentioning

confidence: 99%

Phosphorus reserves increase grass regrowth after defoliation

Oyarzábal

Oesterheld

2009

Oecologia

View full text Add to dashboard Cite

show abstract

“…The replacement of natural grasslands by pastures with perennial cool season grasses and legumes, or the promotion of winter annual grasses through seeding on previously disturbed grassland canopies are common practices that succeed in favoring cool season forage production but require repeated interventions, making them expensive and risky (Oesterheld and León 1987;Hidalgo and Cahuépé 1991;Jacobo et al 2000). Strategic rest regimes to allow winter species regeneration or forage deferral may present less risk and have more limited impact on winter forage availability (Hidalgo and Cahuépé 1991;Jacobo et al 2000). In this context, deciduous tree plantations could be a tool to favor sustained cool season forage production after a single intervention, with the additional benefit of ranch output diversification through forestry.…”

mentioning

confidence: 99%

“…Low primary productivity during winter usually sets the limit of animal carrying capacity in the rangelands of the Pampas (Deregibus et al 1995) and management actions that favor winter primary production have the strongest impacts on animal outputs and ranch profit (Hidalgo and Cahuépé 1991;Jacobo et al 2000). The replacement of natural grasslands by pastures with perennial cool season grasses and legumes, or the promotion of winter annual grasses through seeding on previously disturbed grassland canopies are common practices that succeed in favoring cool season forage production but require repeated interventions, making them expensive and risky (Oesterheld and León 1987;Hidalgo and Cahuépé 1991;Jacobo et al 2000).…”

mentioning

confidence: 99%

Forage production in natural and afforested grasslands of the Pampas: ecological complementarity and management opportunities

et al. 2011

View full text Add to dashboard Cite

In managed rangelands periods of low primary productivity determine troughs of forage availability, constraining animal production yearround. Although alternative tools to increase forage availability during critical seasons exists, most of them are unaffordable and short-lived in marginal areas. We explore the potential benefits of deciduous tree plantations favoring winter forage productivity by comparing aboveground net primary productivity (ANPP) patterns in herbaceous understory to tree plantations and natural grasslands in the Pampas (Argentina). These temperate subhumid grasslands are characterized by the coexistence of winter species, mainly C3 grasses of the native genera Stipa, Piptochaetium, and Bromus and the exotic genera Lolium and Festuca) and summer species (mainly C4 grasses of the native genera Paspalum, Bothriochloa, and Stenotaphrum) that replace each other throughout the seasons, with domination of the latter. We hypothesize that the natural decoupling of growing seasons between winter deciduous trees and winter grasses could provide the basis for the sustainable promotion of winter forage. We measured ANPP on two 23-year-old Populus deltoides plantations and their understory and compared them with adjacent open grasslands. Afforested stands had 55-75% higher annual ANPP than their non-afforested neighbors, with trees contributing *70% to total ANPP. Herbaceous canopies beneath plantations achieved about half of the ANPP observed in nonafforested situations with a contrasting seasonal distribution associated with shifts from C4 to C3 grass dominance. Winter ANPP, the most critical source of forage in these grazing systems, was similar or higher in the herbaceous understory of tree plantations to that on their non-afforested counterparts, suggesting that mixed systems involving deciduous trees and understory pastures are a valid and viable option in the region.

show abstract

“…The functional group approach has been used to study grazing effects in the Flooding Pampa grasslands (Facelli et al 1989;Hidalgo and Cahuépé 1991;Rusch and Oesterheld 1997). This approach allows the comparison among communities of different areas, which can be floristically different but constituted by the same functional groups.…”

Section: Sampling and Data Arrangementmentioning

confidence: 99%

Rotational Grazing Effects on Rangeland Vegetation at a Farm Scale

Jacobo¹,

Rodríguez²,

Bartoloni³

et al. 2006

REM

View full text Add to dashboard Cite

We evaluated the adequacy of rotational grazing to improve rangeland condition in the Flooding Pampa region, eastern Argentina, comparing the floristic composition dynamic of the 2 main plant communities under rotational and continuous grazing over a study period of 4 years (1993)(1994)(1995)(1996). The experiment was conducted in commercial farms located in 4 sites of the Flooding Pampa region. In each site, a couple of farms, one managed under rotational grazing (implemented in 1989) and an adjacent one managed under continuous grazing at a similar stocking rate (1 AU ha À1 ), constituted the replications of the experiment. Basal cover of species, litter, and bare soil were monitored in midslope and lowland grassland communities on each farm. Total plant basal cover in midslope and in lowland communities remained unchanged over the whole experimental period under both grazing methods. Under rotational grazing, litter cover was higher in both communities while the amount of bare soil showed a significant reduction in lowlands and a tendency to be lower in midslope. Basal cover of legumes, C 3 annual and C 3 perennial grasses was higher, while cover of C 4 prostrate grasses was lower under rotational grazing in the midslope community. In the lowland community, rotational grazing effects were evident only in the drier years, when higher cover of hydrophytic grasses and legumes and lower cover of forbs occurred. Plant species diversity did not change in response to grazing. In conclusion, rotational grazing promoted functional groups composed of high forage value species and reduced bare soil through the accumulation of litter. These changes indicate an improvement in rangeland condition and in carrying capacity. As the stocking rate was approximately 60% higher than the average stocking rate of the Flooding Pampa region, we believe that productivity and sustainability may be compatible by replacing continuous with rotational grazing. ResumenPara evaluar si el pastoreo rotativo permite mejorar la condició n de los pastizales de la Pampa Inundable, ubicada al este de Argentina, se comparó durante 4 añ os (1993 a 1996) la composició n florística de las dos principales comunidades vegetales sometidas a pastoreo rotativo o continuo. El experimento se llevó a cabo en establecimientos agropecuarios ubicados en 4 localidades, donde se seleccionaron dos establecimientos, uno manejado con pastoreo rotativo (desde 1989) y otro adyacente manejado con pastoreo continuo, ambos con similares cargas (1 UA ha À1). Se relevó la cobertura basal de las especies, de broza y de suelo desnudo en las comunidades de media loma y de bajo dulce en cada establecimiento. La cobertura basal total de ambas comunidades no se modificó durante el período de estudio bajo ambos sistemas de pastoreo. Bajo pastoreo rotativo, el suelo cubierto por broza fue mayor mientras que el suelo desnudo fue menor en los bajos y mostró una tendencia a disminuir en las medias lomas. En la media loma, la cobertura de leguminosas, de gramíneas invernales anu...

show abstract

Effects of Seasonal Rest in Aboveground Biomass for a Native Grassland of the Flood Pampa, Argentina

Cited by 15 publications

References 5 publications

Phosphorus reserves increase grass regrowth after defoliation

Phosphorus reserves increase grass regrowth after defoliation

Forage production in natural and afforested grasslands of the Pampas: ecological complementarity and management opportunities

Rotational Grazing Effects on Rangeland Vegetation at a Farm Scale

Contact Info

Product

Resources

About