Response of grass species to different fire frequencies in semi-arid rangelands of central Argentina

2013 ◽  
Vol 35 (4) ◽  
pp. 385 ◽  
Author(s):  
Daniel V. Peláez ◽  
Romina J. Andrioli ◽  
Omar R. Elia ◽  
Eliana E. Bontti ◽  
María A. Tomas ◽  
...  
Keyword(s):  
Basal Area ◽  
Bare Soil ◽  
Fire Frequency ◽  
Perennial Grasses ◽  
Moderate Intensity ◽  
Grass Species ◽  
Central Argentina ◽  
Controlled Burns ◽  
Arid Rangelands ◽  
Semi Arid

The study was undertaken to quantify the effect of different controlled fire frequencies on foliar cover, density, individual basal area, and mortality of the most common perennial grass species in the semi-arid rangelands of the southern Caldenal in central Argentina over a 20-year period. Cover of bare soil was also assessed. The study comprised three fire treatments: (i) high fire frequency (controlled burns every 3–5 years; HFF); (ii) low fire frequency (controlled burns every 8 years; LFF); and (iii) unburned control (C). Fire treatments, regardless of frequency, induced an increase in foliar cover and density in desirable grasses, no changes in intermediate grasses, and a decrease in undesirable grasses. Individual basal area tended to be higher for desirable grasses and lower for intermediate and undesirable grasses when subject to fire. Most of the species under study exhibited higher mortality rates in the HFF treatment than in the LFF and C treatments. The results of the study suggest that recurrent controlled burns of moderate intensity may favour the herbage production of desirable perennial grasses. This, in turn, assuming appropriate grazing management, may have a beneficial impact on livestock production. Nevertheless, given the effects of fire on the cover of bare soil and mortality of grasses, further research is needed in order to determine the appropriate fire frequency in terms of rangeland sustainability.

Response of woody species to different fire frequencies in semiarid rangelands of central Argentina

2012 ◽  
Vol 34 (2) ◽  
pp. 191 ◽  
Author(s):  
Daniel V. Peláez ◽  
Romina J. Andrioli ◽  
Omar R. Elia ◽  
Eliana E. Bontti ◽  
María A. Tomas
Keyword(s):  
Woody Species ◽  
Fire Frequency ◽  
Perennial Grasses ◽  
Moderate Intensity ◽  
Similar Response ◽  
Managerial Implication ◽  
Central Argentina ◽  
Canopy Area ◽  
Controlled Burns ◽  
The Individual

The aim of the study was to assess the effect of different controlled fire frequencies on cover, density and mortality of the most common woody species in semiarid rangelands of the Caldenal district of central Argentina over a 20-year period. The study comprised three fire treatments: (1) high fire frequency (controlled burns every 3–4 years; HFF); (2) low fire frequency (controlled burns every 8 years; LFF); and (3) unburned control. Repeated burns of moderate intensity, regardless of frequency, reduced the cover and the individual height and canopy area of the most common woody species. Their density was barely affected and the mortality rates were negligible with woody species producing new sprouts after each burn. The woody species under study had a similar response to the high- and low fire frequency treatments. A controlled burn every 3–4 years, permitted the control of woody species cover, height and canopy area, which in turn may favour the production of desirable perennial grasses. The important managerial implication is that the repeated use of controlled fires of moderate intensities in the autumn, given appropriate grazing management, is likely to be essential to maintain these rangelands.

scholarly journals Influence of woody species on aerial growth of perennial grasses in semi-arid rangelands of central Argentina

Phyton ◽  
2014 ◽  
Vol 83 (1) ◽  
pp. 397-405
Author(s):  
Blazquez FR ◽  
DV Pel醗z ◽  
RJ ◽  
rioli ◽  
OR Elia
Keyword(s):  
Woody Species ◽  
Perennial Grasses ◽  
Central Argentina ◽  
Aerial Growth ◽  
Arid Rangelands ◽  
Semi Arid

Influence of Woody Species on Aboveground Biomass Production and Quality of Two Perennial Grasses in Semi-arid Rangelands of Central Argentina

2020 ◽  
Vol 51 (1) ◽  
pp. 90-98
Author(s):  
Blazquez Francisco Rubén ◽  
Daniel Valerio Peláez ◽  
Romina Jessica Andrioli ◽  
Omar Raúl Elia
Keyword(s):  
Biomass Production ◽  
Aboveground Biomass ◽  
Woody Species ◽  
Perennial Grasses ◽  
Central Argentina ◽  
Arid Rangelands ◽  
Semi Arid

The response to moisture and defoliation stresses, and traits for resilience of perennial grasses on the Northern Tablelands of New South Wales, Australia

2003 ◽  
Vol 54 (9) ◽  
pp. 903 ◽  
Author(s):  
S. P. Boschma ◽  
M. J. Hill ◽  
J. M. Scott ◽  
G. G. Rapp
Keyword(s):  
Festuca Arundinacea ◽  
Plant Biomass ◽  
Nitrogen Concentration ◽  
Perennial Grass ◽  
Basal Area ◽  
Perennial Grasses ◽  
Rooting Depth ◽  
Grass Species ◽  
Severe Drought ◽  
Moderate Drought

A field experiment was conducted to study the effects of defoliation and moisture stresses on perennial pasture grasses and to identify traits associated with their resilience. The experiment, conducted near Armidale on the Northern Tablelands of NSW, studied 4 introduced perennial grass species (Phalaris aquatica, Festuca arundinacea, Dactylis glomerata, and Lolium perenne) and 2 native grass species (Microlaena stipoides and Austrodanthonia richardsonii) subjected to 3 moisture regimes (non-stress moisture, moderate drought, and severe drought) and 2 defoliation intensities (severe and moderate). Basal area, herbage mass, phenological growth stage, nitrogen concentration, root mass, and rooting depth were compared over 2 independent 6-month periods: spring–summer (1 September 1994–28 February 1995) and summer–autumn (1 December 1994–31 May 1995). Multiple regression was used to determine which traits were important for determining plant resilience.The differences between species and their respective responses were evident in the traits measured. In general, basal area tended to increase over summer and show little change during autumn. Severe defoliation stimulated plant growth, resulting in higher harvested herbage mass than from those moderately defoliated. Reproductive development was suppressed by severe drought and reduced by moderate drought. Severe defoliation suppressed flowering of Dactylis and Lolium at both drought intensities, compared with moderate defoliation. Phalaris, Festuca, and Austrodanthonia were the deepest rooting species during spring–summer, and Dactylis the shallowest. All species had similar rooting depths during summer–autumn, with those under severe and moderate drought having the deepest and shallowest rooting, respectively.Carbohydrate reserves and basal area were important traits for determining plant resilience during spring–summer. During summer–autumn, maintaining basal area and plant biomass through moderate grazing was important for resilience.

scholarly journals Effects of the Management of Extensive Beef Grazing Systems on the Mitigation of Greenhouse Gas Emissions in Semi-arid Rangelands of Central Argentina

2018 ◽  
Author(s):  
María I. Nieto ◽  
Olivia Barrantes ◽  
Liliana Privitello ◽  
Ramón Reiné
Keyword(s):  
Management Practices ◽  
Linear Models ◽  
Ghg Emissions ◽  
Farm Management ◽  
Forage Crops ◽  
Central Argentina ◽  
Livestock Sector ◽  
Arid Rangelands ◽  
On Farm ◽  
Semi Arid

The livestock sector can be a major contributor to the mitigation of greenhouse (GHG) emissions. Within the sector, beef production produces the largest proportion of the livestock sector’s direct emissions. The objective of this study was to assess the on-farm GHG emissions in semi-arid rangelands in Argentina and to identify the relationships between emissions and current farm management practices. A survey recorded detailed information on farm management and characteristics. Assessments of GHG emissions were based on the IPCC Tier 2 protocols [1]. The relationships between farm management and GHG emissions were identified using General Linear Models. Cluster analysis was used to identify groups of farms that differed from others in emissions and farm characteristics. Emissions per product sold were low on farms that had improved livestock care management, rotational grazing, received technical advice, and had high animal and land productivities. Emissions per hectare of farmland were low on farms that had low stocking rates, low number of grazing paddocks, little or no land dedicated to improved pastures and forage crops, and low land productivity. Our results suggest that the implementation of realistic, relatively easy-to-adopt farming management practices has considerable potential for mitigating GHG emissions in semi-arid rangelands of central Argentina.

scholarly journals Morphoecological characteristics of grasses used to restore degraded semi-arid African rangelands

2021 ◽  
Author(s):  
Kevin Mganga
Keyword(s):  
Ecological Restoration ◽  
Seed Production ◽  
Dry Matter ◽  
Perennial Grasses ◽  
Grass Species ◽  
Rhodes Grass ◽  
Basal Cover ◽  
Plant Densities ◽  
Chloris Gayana ◽  
Semi Arid

<p>Progressive loss of productivity and plant diversity is a major in global rangelands. In African rangelands ecosystems, this process is partly attributed to heavy and uncontrolled grazing by livestock and wildlife, leading to land degradation. Therefore, restoring such degraded rangelands is critical for enhancing ecosystem health and securing the livelihoods of millions of people. Active restoration strategies, e.g. reseeding using indigenous perennial grasses has been identified as a viable ecological solution for restoring degraded African rangelands. Grass species indigenous to African rangelands Cenchrus ciliaris L. (African foxtail grass), Eragrostis superba Peyr. (Maasai love grass), Enteropogon macrostachyus (Hochst. Ex A. Rich.) Monro ex Benth. (Bush rye grass), Chloris roxburghiana Schult. (Horsetail grass) and Chloris gayana Kunth. cv Boma (Rhodes grass) were established in a semi-arid rangeland in Africa under natural conditions to compare their morphoecological characteristics and suitability for use in ecological restoration. Biomass dry matter yields, plant densities, basal cover, seed production, tiller densities and plant height were measured. Chloris gayana cv Boma and E. superba produced significantly higher dry matter biomass yields and seed production than other species. High biomass and seed production demonstrate their suitability to support livestock production and replenish depleted soil seed banks, respectively. Enteropogon macrostachyus and C. ciliaris displayed significantly higher values for plant densities, tiller densities and basal cover, also a component of establishment and ecological restoration success. Chloris roxburghiana ranked lowest in all the measured morphoecological characteristics. This may be a strong indicator of ecological site-specific characteristic of C. roxburghiana. Successful restoration of degraded African semi-arid rangelands using indigenous grass reseeding can best be achieved through careful selection of grasses to take advantage of their specific morphoecological characteristics. This selection should primarily be informed by the intended use of the rangeland.</p>

Changes in Grass Density in Australian Semi-Arid Woodlands.

1995 ◽  
Vol 17 (1) ◽  
pp. 26 ◽  
Author(s):  
AC Grice ◽  
I Barchia
Keyword(s):  
Perennial Grass ◽  
Perennial Grasses ◽  
Grass Species ◽  
European Settlement ◽  
Eastern Australia ◽  
Rate Of Response ◽  
Semi Arid

Changed grazing regimes since European settlement have been widely proposed as the cause of a decline of indigenous perennial grasses in the semi-arid woodlands of eastern Australia. A five year experiment using exclosures examined the effects of grazing on densities of perennial grasses. Short- lived Stipa spp. and Aristida spp. were dominant at most sites. Their densities fluctuated greatly with season and reached over 200 plants/m2 during climatically favourable periods. The long-lived Eragrostis eriopoda occurred at densities that were generally less than 5 plants/m2 and its populations were relatively stable. The response of Enneapogon avenaceus was distinctive. Though its density fluctuated considerably, successive peaks in density were higher and the species increased more in ungrazed areas than in destocked or unfenced areas. The differences between grazed and ungrazed populations became greater with successive peaks in density. Within the short periods that pastoralists are likely to be willing or able to apply such treatments, destocking or even removing all herbivores is unlikely to have a large effect on the density of many palatable perennial grass species. The rate of response to resting pastures will depend on seasonal conditions.

Landscape ecology of the burrowing bettong: fire and marsupial biocontrol of shrubs in semi-arid Australia

2007 ◽  
Vol 29 (1) ◽  
pp. 107 ◽  
Author(s):  
James C. Noble ◽  
David S. Hik ◽  
Anthony R. E. Sinclair
Keyword(s):  
Habitat Preferences ◽  
Fire Frequency ◽  
European Settlement ◽  
South Wales ◽  
Arid Rangelands ◽  
Native Shrubs ◽  
In Fire ◽  
The 19Th Century ◽  
Semi Arid ◽  
Stony Hard

Prior to European settlement, medium-sized marsupials, especially bettongs (Bettongia spp.), were widely distributed across arid and semi-arid Australia. Most disappeared rapidly in the late 1800s in the earliest settled rangelands such as the West Darling region of western New South Wales following the spread of domestic herbivores, rabbit invasion, exotic predators and loss of habitat. Because the burrowing bettong (Bettongia lesueur) is the only fossorial macropod species, it left a clearly visible record of its past presence, distribution and habitat preferences in the form of substantial relict warrens, particularly in stony, ‘hard-red’ habitats. With the reduction in fire frequency because of excessive grazing pressures following European settlement in the 19th century, there was a rapid increase in the density of unpalatable native shrubs. We examine the hypothesis that periodic wildfires and browsing by bettongs were together able to regulate shrub densities in semi-arid rangelands in Australia. Information from various sources concerning the effects of fire, rainfall and browsing on the demography of shrubs was used to construct a model of shrub population dynamics. The model indicates the potential for two states for a given bettong density: first, a low shrub density maintained by a combination of periodic fire and bettong browsing; and second, a high shrub density in the absence of fire. These results have broad implications for pastoral and conservation management in Australian semi-arid rangelands.

Effects of nitrogen and phosphorus on vegetation dynamics of a degraded native grassland in semi-arid south-eastern Australia

2011 ◽  
Vol 33 (1) ◽  
pp. 87 ◽  
Author(s):  
R. B. Hacker ◽  
I. D. Toole ◽  
G. J. Melville
Keyword(s):  
Vegetation Dynamics ◽  
Plant Density ◽  
Perennial Grass ◽  
Ground Cover ◽  
Perennial Grasses ◽  
Grass Species ◽  
Nitrogen And Phosphorus ◽  
Mineral N ◽  
Eastern Australia ◽  
Semi Arid

The roles of nitrogen (N) and phosphorus (P) in controlling vegetation transitions in a degraded semi-arid grassland were investigated in a factorial experiment that combined two initial levels of perennial plant density (low and high), three levels of N (N+, N0 and N–) and two levels of P (P+ and P0). Increased levels of both N and P were achieved by fertiliser addition while sucrose was used to reduce the level of N. Vegetation dynamics were driven primarily by soil N rather than P. Addition of sucrose, which was inferred to result in the immobilisation of mineral N, reduced the growth of annual species and facilitated the establishment and growth of native perennial grasses. Addition of P generally had no significant effect on dry matter production, either in total or for species grouped as forbs, annual grasses and perennial grasses, or on recruitment and mortality of perennial grasses. However, at some times of observation addition of P increased ground cover and/or the basal circumference of some perennial grass species. Basal circumference for Enteropogon acicularis was also increased by addition of N. Soil biological activity, measured by decomposition of cotton strips, was increased by addition of N, which maintained vegetation in an annual-dominated condition, and was not affected by addition of P. Carbon addition has the potential to assist restoration of this grassland. However, the capacity of some native grass species to respond to increased fertility suggests that once restoration is achieved some increase in fertility may be beneficial for pastoral production.

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