Native Rangeland Research Articles

Fire management effects on ruminal digestibility and in vitro methane emissions of subtropical rangeland plant species.

Prescribed fire is a common management practice used to manipulate rangeland plant productivity and composition. Although the nutritive value of most herbaceous plant species is considered poor for grazing animals, native rangelands in Florida are an important source of forage for livestock, especially during the winter months, when the productivity of cultivated perennial warm-season pastures is limited. This study evaluated the effects of prescribed fire on methanogenic potential and nutritive value of selected native rangeland plant species. Treatments were a 3 × 2 factorial arrangement of plant species (creeping bluestem [Schizachyrium scoparium var. stoloniferum {Nash} Wipff], wiregrass [Aristida stricta {Michx.}], or saw palmetto [Serenoa repens {W. Bartram} Small]) and prescribed fire management [2 yr after burning (control) vs. 1 yr after burning (burned)] distributed in a randomized complete block design with four replicates. Samples were analyzed for crude protein (CP), neutral detergent undigestible fiber (NDF), in vitro methane production, and in situ ruminal disappearance. Prescribed fire generally increased forage CP and DM effective degradability relative to control; however, no effect was observed on saw palmetto. Wiregrass had the least CP concentration in both burned (8.5%) and control (2.3%). In burned treatments, creeping bluestem and palmetto had greater DM effective degradability (62% and 58%) than wiregrass (53%). Fire increased in vitro gas production by 60 (creeping bluestem) to 90% (wiregrass) relative to control treatments. No effect of fire on methane production was observed for any of the plant species evaluated in this study. Creeping bluestem had the greatest methane production (12.5 mg/g DM), followed by wiregrass (5.3 mg/g DM) and saw palmetto (1.4 mg/g DM). Methane:DM effective degradability decreased in the following order: creeping bluestem ≥ wiregrass > saw palmetto. Data indicated prescribed fire was an effective tool to increase creeping bluestem and wiregrass nutritive value but no effect was observed on saw palmetto. Cattle grazing grass-dominated rangelands will likely emit more gas and methane than shrub or tree-dominated ecosystems; however, the greater forage nutritive value and subsequent positive impacts on animal production are expected to offset a substantial fraction of enteric methane emissions.

Effects of Prescribed-Fire Timing on Stocker Cattle Performance, Forage Biomass Accumulation, and Native Plant Species Composition

Objective: The objective of this experiment was to document the effects of prescribed-fire timing on stocker cattle performance, forage biomass accumulation, soil cover, and plant species composition in the Kansas Flint Hills. Study Description: A total of 1,416 yearling stocker cattle were assigned to one of three prescribed-burn treatments: spring (April 9 ± 5.1 days), summer (August 23 ± 4.9 days), or fall (September 29 ± 8.7 days) over a 4-year period. Calves were grazed from May to August for 90 days. Individual body weights were recorded at the beginning and end of the grazing season. Native plant composition and soil cover were evaluated annually using a modified step-point method, and forage biomass was measured biannually. The Bottom Line: Flint Hills ranchers can employ late-summer prescribed fires to manage sericea lespedeza (Lespedeza cuneata) infestations without negatively impacting stocker cattle growth performance, forage biomass accumulation, or native rangeland plant species composition.

The Blue Water Footprint of Extensive Beef Production on Semi-Arid Rangeland over a Full Production Cycle in South Africa

Water plays a critical role in beef cattle production. Current methods used to estimate the blue water footprint of beef cattle are largely based on generic values that do not make provision for different production systems within different regions. Total production cycle measurements should therefore be considered to accurately assess the blue water footprint of beef cattle grazing natural rangeland. The aim of the study was to measure water intake of extensive Bonsmara cattle grazing Marikana Thornveld over a full production cycle at the ARC-Roodeplaat Research Station. Measurements commenced at weaning (June 2017) and continued until the heifers weaned their first calves at approximately 210 days of age (July 2019). Water consumption differed between 21.4 litre per animal per day when the heifers were still growing to 54.3 litres during lactation, relating to between 6.7% and 12.0% of live weight. The blue water footprint over the total production cycle was calculated to be 27,147 litres.

A preliminary investigation of the effect of solar panels and rotation frequency on the grazing behavior of sheep (Ovis aries) grazing dormant pasture

Vegetation management on solar farms can be accomplished through targeted grazing with sheep. To the authors’ knowledge, no research has been conducted to date on sheep grazing behavior on solar farms, yet such research is crucial to inform grazing management practices for contract grazers on solar farms. The objectives of this study were to investigate both the effects of solar panels on sheep grazing behavior and the grazing management strategy (intensive rotational grazing (1-day rotations (1d))) or rotational grazing (4-day rotations (4d))) best suited for vegetation management on a solar farm. Data were collected on Gold Tree Solar Farm in San Luis Obispo, CA, USA. Sheep with predominantly Dorper genetics (over 99%; n = 80) were stratified by body weight (BW) and age in a crossover design across treatment grazing locations, solar farm (S) or native rangeland (NR), and grazing managements, intensive rotational (1d) or rotational (4d). Grazing location treatments (S or NR) were randomly assigned a grazing management, 4d (paddock size = 0.405 ha, 4 days/paddock), or 1d (paddock size = 0.101 ha, 1 day/paddock, 4 paddocks), resulting in a 2 × 2 factorial design. All sheep were equipped with a HOBO Pendant G data logger (Onset Computer Corporation, Bourne, MA, USA) in a medial-dorsal position on their necks using vet wrap (Dura-Tech), to record ‘grazing’ behavior, defined as standing or walking slowly with the head down. The sensitivity, accuracy, and precision were > 90% for ‘grazing’ behavior with 2-minute intervals. ‘Grazing’ behavior exhibited a treatment × management (< 0.01) interaction. Both solar (S-4d and S-1d) groups spent more time (< 0.01) ‘grazing’ than both NR (NR-4d and NR-1d) groups. The presence of solar panels may have provided sheep relief from heat, wind, and rain, which could increase grazing activity. During the study, forage was senescent and low-quality in terms of nutritive value. Both forage digestibility and protein content were higher in the S than in the NR paddocks. Sheep spent less time ‘grazing’ under intensive rotational management (1d) when compared with rotational management (4d) (< 0.001). The use of sheep for vegetation management on solar farms has great potential. Sheep are effective grazers, easily able to maneuver between solar panels and can graze on steep slopes utilizing the panels to provide shade and protection from climatic conditions. In conclusion, utilizing a mix of intensive rotational and rotational grazing according to forage conditions – rotational 4d grazing management types being most effective for grazing behavior with senescent forage conditions – may be the most effective grazing management strategy on solar farms.

Study on distinct quality properties of cashmere from local goat breeds of Mongolia

The research was carried out in 2021 to determine the specific quality properties of local Mongolian breeds of cashmere goats. The research covered 122 herder households from 13 soums in 8 aimags. A total of 4,560 samples were collected from 1,522 goats representing the main factors determining cashmere quality: ecological habitat, various herd management practices, local breeds, age and sex of goats, and cashmere colour. Cashmere fibre diameter (FD), fibre curvature (FC), and coefficient of variation of fibre diameter (CVFD) were tested in 1,522 samples, and cashmere length was tested in 1,387 samples. The overall mean fibre diameter (MFD) was 16.1 μm, mean length (FL) was 44.9 mm, and fibre curvature (FC) was 61.9°/mm. Cashmere from one-year-old goats was significantly finer than cashmere from older goats (about 1.0 μm, P&lt;0.05). Cashmere from does in the samples tested was significantly finer than cashmere from the bucks. Over the range in mean fibre diameter, from 13.5 to 19.0 µm, fibre curvature declined from 87.8 to 44.2°/mm. Of all cashmere samples, 40.6% belonged to super fine (≤15.5µm), 43.7% and 12.1% had a fibre diameter between 15.51-16.80 and 16.81-17.50 μm, respectively, and were suitable for knitwear. Only 3.6% of samples tested were between 17.51 to 19.00 μm and may only be suitable for weaving. The average CVFD values of cashmere of Mongolian breeds of cashmere goats was 22.5 ± 0.04%, with an individual range of 17.0-26.9%. This shows that it has lesser variation than Alashan white cashmere goats of Inner Mongolia Autonomous Region, China, where CVFD ranged from 27.09% to 41.39%. Compared to cashmere from China, Tajikistan, and Kyrgyzstan, with mean fibre curvature of 46, 46, and 58mm, respectively, the cashmere of local Mongolian breeds of goats would be considered curvier and longer, which makes stronger yarns. Short, higher crimped, softer cashmere may be preferred for woollen-spun yarns, but longer, lower crimped, softer cashmere may be preferred for woven yarn destined for knitwear. Fibre curvature of Mongolian cashmere goats declined an average of 6.1°/mm for a 1µm increase in MFD, which is similar to the 5.8°/mm observed in Chinese Liaoning goats, but less than the 13.6°/mm measured in controlled experiments with Australian goats. Significant differences were found between the cashmere of local Mongolian breeds of goats kept in open, natural rangelands and herded in a nomadic way in distinct ecological conditions of harsh continental climate compared to those breeds of goats kept in intensive farming. This shows the potential to offer distinct quality cashmere from local Mongolian breeds while maintaining proper management and selective breeding.

Soil sample storage conditions impact extracellular enzyme activity and bacterial amplicon diversity metrics in a semi-arid ecosystem

The analysis of microbiological and metabolic features of soils is an important aspect of soil ecology, but the results can be heavily impacted by sample storage conditions. Inconsistencies in storage methods and length of storage across studies reduce the ability to accurately collect field-based measures and compare results between projects. In this study, we examined the effects of various storage conditions and storage time on results of subsequent bacterial 16S rRNA amplicon sequencing and on activities of extracellular enzymes, using soil samples collected from three different land use types (annual cropping system, native rangeland, and riparian forest) in a semi-arid region of the Canadian Prairies. We found that when comparing enzyme activities and bacterial communities across different land use types, storage conditions may not have a significant impact. However, storage conditions were found to be important within a single land use type. Air-drying of soil samples caused significant shifts in enzyme activity and β-diversity from the controls. Storage at −80 °C was best for maintaining consistent enzyme activity and microbial α- and β-diversity compared to controls (i.e., freshly collected soil) across all three land use types and storage times. The results from this study provide useful information about the impact of sample storage conditions for researchers in similar climates and encourage further consideration and discussion of the impacts of sample storage, as well as the reporting of storage conditions used in future studies.

Zonguldak ili Nebioğlu yöresi doğal meralarının toprak ve vejetasyon özelliklerinin belirlenmesi

The aim of this study was to determine the ecological characteristics of natural rangelands. For this purpose, four different natural pastures were studied in Nebioğlu region in Zonguldak province. When the studies on the subject were examined, it was determined that, while studies were carried out on pastures in almost every region of our country; such a study has not been conducted in the Nebioğlu region before. This situation increases the original value of the research. Vegetation cover in the study areas were identified and the botanical composition was checked at the family level, including Fabaceae, Poaceae and other genus. Soil sampling was done in pasture areas. A total of 40 soil samples, compiled from 10 randomly taken samples from each study area, were subjected to some physical, chemical and biological analyses. In the collected soil samples, soil texture class, actual pH (H2O), lime content, electrical conductivity, total nitrogen, organic carbon, available phosphorus and available potassium contents were analyzed. According to the results of the study, one way-Anova analysis of variance was performed in the SPSS program in order to understand if the Fabaceae, Poaceae, other genus ratios and soil properties are different among the research areas. Duncan test was applied to determine different groups. According to the results of the study, the canopy coverage of vegetation was calculated as 100% in all pasture areas. The highest rate of legumes was in Hallaç rangeland with 48.7%, grasses rate was in Gölyanı range with 39.8%, other genus rate was 30.8% in Alçak and Hallaç pastures; The lowest rate of legumes was found in Alçak pasture with 38.3%, the rate of grasses in Hallaç with 20.5%, and the rate of other families in Gölyanı range with 20.1%. According to the results of the soil analysis, it was determined that the soils in all pasture areas were in the clayey soil class, slightly alkaline and had low electrical conductivity.

PSIII-A-17 Relationships between Diet Quality and Serum Metabolic Indicators in Prenatally Stressed Growing Bos Indicus Heifers

Abstract Our research group has previously reported on grazing behavior, diet selection, and weight change in prenatally stressed and translocated Brahman heifers grazing native rangeland. Our current objective was to evaluate relationships between diet quality and metabolic indicators. Twelve yearling heifers were transported ~700 km from Overton, TX to Sonora, TX. Six heifers (283±10 kg) were born to dams subjected to transportation stress during mid-gestation (PNS) and 6 (279±17 kg) were born to non-stressed dams (CON). Heifers grazed a series of 24-ha native range pastures and were sampled (BW, BCS score, blood, and feces) at 2-wk intervals from May through September. Fecal samples collected from the ground or the rectum of each animal were stored at -20o C until processed for near infrared reflectance spectroscopy prediction of diet crude protein (CP) and digestible organic matter (DOM). Blood was obtained via coccygeal venipuncture and processed to yield serum. Serum analyses were obtained from the Texas A&amp;M Veterinary Medical Diagnostic Laboratory. Relationships between constituents of interest were determined by linear regression. Significance was considered to be P &amp;lt; 0.05. Blood urea nitrogen (BUN; mg/dL) was greater (P = 0.04) in PNS (8.39±0.32) than CON (7.39±0.33). Positive correlations were found between CP and BUN (RSQ = 0.76, SE = 1.25 mg/dL; P &amp;lt; 0.001), albumin (RSQ = 0.57, SE = 0.06 mg/dL; P &amp;lt; 0.01), and average daily gain (RSQ = 0.63, SE = 0.47 kg; P &amp;lt; 0.01). Similar relationships were observed between DOM and glucose (RSQ = 0.64, SE = 3.91 mg/dL; P &amp;lt; 0.01), cholesterol (RSQ = 0.37, SE = 5.47 mg/dL; P &amp;lt; 0.05), and average daily gain (RSQ = 0.47, SE = 0.56 kg; P &amp;lt; 0.01). PNS affected circulating nitrogen concentration. Diet quality was related to weight gain and serum indicators of nutritional status.

Traditional breeding of small ruminants in the North-West of Benin: practices and inventory of food resources

The northern part of Benin is a favourite area for ruminant breeding in view of its pastoral resources and the many other assets it has at its disposal. The objectives of this study were (i) to characterize small ruminants rearing practices in north-western Benin, (ii) to assess factors that affect the described practices (iii) and to inventory the feed resources used in the ruminant breeding. To achieve these objectives, a retrospective survey was carried out in four municipalities located at north-west Benin. The results showed that sheep and goats are mostly raised by men (94.93%). Digestive disorders (90.41%) are the main diseases encountered. The results of linear regression analysis showed that sociocultural group and education level of the respondents have a significant influence on the mode of management and the practice of castration of small ruminants. Feeding was based on fodder from natural rangelands, notably Rottboellia cochinchinensis and Adenodolichos paniculatus. These fodders content respectively, 17.71% and 20.4% of Total Nitrogen Matter (TNM). Breeders used crop residues, notably legume tops, food processing residues and fodder trees during the lean season. In view of this multitude of food resources, possibilities for improving the existing small ruminants breeding system are proposed.

Effects of Native and Non-Native Invasive Grasses on Northern Bobwhite Habitat in South Texas

Usable space for northern bobwhite (Colinus virginianus) has been reduced across South Texas rangelands because of the spread of non-native, invasive grasses. A native grass, tanglehead (Heteropogon contortus), has also rapidly expanded its dominance in South Texas within the past 25 yr. It has formed high-density monocultures, similar to non-native grasses, which are associated with losses of herbaceous diversity and bare ground, both key components of bobwhite habitat. The objectives of our research were to 1) determine selection-avoidance of invasive grass cover by bobwhites and 2) determine effects of invasive grass cover on vegetation characteristics.We hypothesized the effects of tanglehead on bobwhite would be negative and similar to the effect of non-native grasses in the region. We recorded covey locations via helicopter surveys in December 2014 and 2015, with field measurements of bobwhite habitat at covey and random locations taken each spring. We measured grass and forb species richness, herbaceous vegetation height, woody-plant cover, tanglehead canopy cover, and non-native grass canopy cover at all covey detections and an equal number of random locations. We developed continuous selection ratios using Simple Saddlepoint Approximations to determine habitat selection by bobwhites. We also used quantile regression, at the 10th, 50th, and 90th quantiles, to determine relationships between invasive grass cover and vegetation factors. Bobwhites avoided areas of high canopy cover (> 20%) of all invasive grasses measured. We found negative relationships between native and non-native invasive grass cover and forb and grass species richness, as well as bare ground, and a positive relationship with herbaceous vegetation height at all quantiles modeled. Our results demonstrate the negative effects of increased tanglehead cover on native rangeland habitats, which aligns with similar non-native invasive grasses. Further expansion by tanglehead has the potential to significantly reduce usable space for bobwhites in South Texas.

Nutrient transfer in rangelands under rock powder amendment

AbstractBackgroundNative pasture yields are soil nutrient limited in subtropical regions. The use of powdered rock as a soil amendment is increasing in these regions as it can supply plant nutrients, increasing the yield of pasture in traditional livestock farming systems. Although powdered rock may also be useful to preserve native rangelands, little is known about the nutrient dynamics in rangeland soil–plant systems amended with powdered rock.AimsWe evaluated the chemical characteristics of an Acrisol and the grassland production treated with different rates of hydrothermalized basalt powder (HBP) to estimate the nutrient transfer from soil to plants in a rangeland.MethodsDifferent HBP doses (0, 1, 2, 4, and 8 t ha−1) were applied twice to the native rangeland topsoil, to which soluble fertilizer was never applied. Soil and plant samples were collected and chemically evaluated seven times over 2 years (674 days).ResultsThe soil copper (Cu) and potassium (K) contents increased with the HBP dose, while the available phosphorus (P) and potential acidity (H+Al) decreased. The soil pH temporarily increased. The HBP doses did not affect the exchangeable calcium (Ca), magnesium (Mg), or aluminum (Al) contents. The nutrient concentrations in plant dry mass tended to increase for P, K, Ca, and Mg due to the transfer from the soil. The shoot dry mass increased with the HBP dose according to the growth season of the pasture.ConclusionThese findings suggest that application of HBP improves the soil‐native pasture system by the transfer of nutrients from soil to plants and by increasing dry mass yield. Rock powder application in native pastures (low chemical fertility and acid conditions) is a feasible agronomic alternative for increasing pasture yield with low impact on the system.

Indaziflam Reduces Seed Bank Richness and Density but not Sagebrush-Grassland Plant Diversity

Mitigating invasive annual grass impacts is critical to halting native rangeland conversion to fire-prone, annual grass-dominated communities and maintaining the ecosystem services provided by perennial plants. The herbicide indaziflam (Rejuvra, Bayer, Leverkusen, Germany) may allow managers to selectively deplete annual grass seed banks in plant communities that continue to support desirable perennial vegetation, but nontarget impacts are difficult to assess in the small plots typically used in herbicide trials, and the potential for impacts to the seed bank is not well understood. To assess the potential for nontarget impacts resulting from indaziflam treatment, we used modified-Whittaker multiscale vegetation plots to compare diversity (species accumulation) in three treatment plots (73 g ai ha−1 indaziflam) and three control plots in sagebrush-grasslands near Pinedale, Wyoming that are invaded by cheatgrass (Bromus tectorum L.). We also assessed the density and richness of shallow (0- to 1-cm depth) and deep (1- to 5-cm depth) germinable seed banks in treatment and control plots by tracking seedling emergence from seed bank samples during a 20-wk greenhouse study. Vegetation data and seed bank samples were collected during the third growing season after treatment. Treatment did not impact aboveground species diversity, but this contrasted with the results of the seed bank assay; shallow and deep native seed bank density and shallow native seed bank richness were significantly reduced in treatment plots. All impacted species were detected in the aboveground plant community in treatment plots after herbicide application, suggesting that reduced native annual abundance may be temporary. Considering the potential for nontarget impacts to seed banks will help land managers accurately assess trade-offs when making treatment decisions.

Seasonal dynamics of magnesium in rangeland areas of Southeastern region of Rio Grande do Sul State/Brazil: 1. field research

We aimed to evaluate the seasonal dynamics of magnesium (Mg) in the system soil - plant - animal. It was conducted in two natural rangeland areas on two types of undisturbed soils (medium-clayey texture) in the Serra do Sudeste region (Rio Grande do Sul State, Brazil). In each area, 12 heifers were kept under continuous extensive grazing for twelve months without mineral supplementation. Samples of soil and vegetation were collected monthly from 16 fixed points and blood serum from each of the animals in each area monthly for the determination of Mg levels. The data were analyzed by analysis of variance, decomposition of the annual variation of the response variables and regression (harmonic analysis) for adjustment of function to express this variation. The Mg content in the soils of the two areas was high (1.86 ± 0.045 cmolc.dm-3). Mg levels in the vegetation (0.23 ± 0.0025 % DM) are sufficient to meet the needs of all categories of ruminants. The Mg contents in the blood serum (3.05 ± 0.0025) of grazing animals are considered medium to high and in normal levels. Mg supplementation is suggested in the cold season months for the most demanding animal categories (gestating and lactating females).

Dynamics of magnesium in rangeland areas of Southeastern region of the State Rio Grande do Sul/Brazil. 2. Correlations

We aimed to evaluate the dynamics of magnesium (Mg) in the soil - plant – animal chain. It was conducted in two natural rangeland areas on two types of undisturbed (virgin) soils (medium/clayey texture) in the Serra do Sudeste (Rio Grande do Sul State, Brazil). In each of these areas, 12 animals (heifers) were kept under continuous extensive grazing for twelve months without mineral supplementation. Every month, samples of soil and vegetation were collected at 16 fixed points (radius: 25 m) as well as blood serum from each of the animals in each area for the determination of Mg and other minerals levels. The data were analyzed using the analysis of variance, decomposition of the annual variation of the response variables and periodic regression (harmonic analysis) for adjustment of function to express this variation. The relationship of Mg with other variables within the links of the soil-plant-animal chain is influenced by some factors such as physicochemical and biological soil reactions, floristic composition and environmental conditions. In natural non perturbed rangeland areas the organic matter is the main colloid of the soil for the availability of magnesium to plants and, consequently, to the animals.

Plant Litter Chemical Characteristics Drive Decomposition in Subtropical Rangelands Under Prescribed Fire Management

Rangelands used for cattle grazing in Florida are typically managed under prescribed fire to increase forage production and nutritive value while preventing shrub encroachment. Sustainability of extensively managed, low-input native rangelands is highly dependent on nutrient cycling through plant litter decomposition, which is often constrained by limited N availability. We evaluated the effect of prescribed fire (Unburned vs. Burned), N addition (0 vs. 180 kg N ha−1 yr−1), and species composition (Palmetto [Serenoa repens Bartr.] [100% saw-palmetto], Palmetto-Grass [50−50% mixture of saw-palmetto and grasses], and Grass [chalky bluestem, Andropogon capillipes Nash.; lopsided indiangrass, Sorghastrum secundum {Elliott} Nash]) on aboveground plant litter decomposition and N and P mineralization using field incubated litterbags over 224 d in a split-split plot design with three replicates. Litter disappearance followed a single exponential decay model (P ≤ 0.01) and was mainly driven by plant litter chemical characteristics. At the end of the 224-d incubation, remaining plant litter was less in Palmetto (62%) compared with other treatments (∼72%), possibly due to more favorable chemical characteristics associated with Palmetto treatment (43, 65, and 112 C:N ratio; and 15, 20, and 25 lignin:N ratio for Palmetto, Palmetto-Grass, and Grass, respectively). Remaining N was less (greater N mineralization) in Palmetto (79%) compared with Palmetto-Grass treatment (92%) but was not different from Grass (P ≥ 0.12, 86% remaining N). Greater lignin and proportion of N bound to fiber observed at the end of incubation suggested increased C and N recalcitrance as a result of decomposition. Nutrient inputs through ash or N addition suppressed litter net P and N mineralization. These results suggest litter quality, particularly N concentration and C:N and lignin:N ratios, are the main drivers in nutrient cycling through plant litter decomposition in Florida rangelands.

Characterization of Goat Breeding Systems in Tunisia and In the Mediterranean Region

Despite its socio-economic role in Tunisia, the goat has been considered as an agent of natural resource degradation due to the excessive exploitation of forests and rangelands. Currently goat farms are beginning to regain interest in different Tunisian climatic conditions. Goat breeding is distributed throughout the territory, particularly in the mountain areas, natural rangelands and southern oases. The main systems encountered are (i) systems integrated into farms, (ii) livestock systems in mountainous and forest regions, (iii) oasis ecosystems and (iv) transhumant livestock systems. These farming modes are influenced by developments in agricultural systems in general, which change due to socio-economic development and are dependent on the availability of funding through national projects. In North African countries in general, transhumant pastoral systems dominate arid and semi-arid zones and are characterized by the seasonality of food resources, which are tightly influenced by rainfall. Extensive pastoral farming, mixed with sheep in regions with a dry climate and limited water resources, is the most widespread. Goat farming is a form of savings rather than an economic activity. Concerning the majority of Mediterranean countries; the existing farming systems reveal the importance of socio-territorial unity and available natural resources. The classification of goat farming systems is based on the resources used (natural rangelands or crop residues), the intensity of resource use (extensive or intensive), the types of livestock breeders (nomadic or sedentary), or the product generated and it's quality. The dominant systems in the European countries of the northern Mediterranean shore are farms oriented to the production of goat's milk intended for the manufacture of cheeses.

Life cycle assessment of bioenergy from lignocellulosic herbaceous biomass: The case study of Spartina argentinensis

One of the main initiatives in the context of global warming brought by the COP26 is global transition to green energy. Bioenergetic utilization of unharnessed renewable resources, such as native rangeland frequently subjected to fires, is a promising alternative to displace fossil fuels. Spartina argentinensis is a native perennial grass that develops in a depressed area of 33,000 km2 in Santa Fe province (Argentine) named “Los Bajos Submeridionales”. A life cycle assessment (LCA) was performed analyzing the bioenergetic utilization of S. argentinensis. Two alternative scenarios (AS) were assessed and compared to their business as usual (BAU) counterparts: pellets for i) gasification to deliver electricity to the grid (ASp), contrasted to the Argentinean energy mix (BAUp) and ii) residential heating (ASh) contrasted to natural gas heating (BAUh). Carbon Balance of both AS were negative noticeably lower than BAU and the energy balance was promising considering that the produced energy was higher than that required along the complete system assessed. This is the first LCA of bioenergy from S. argentinensis and according to the results, this biomass resource could collaborate remarkably in climate change mitigation, which is auspicious considering the vast region occupied by this grass and others with similar characteristics.

Short duration overnight cattle kraaling in natural rangelands: Does time after kraal use affect their utilization by wildlife and above ground grass parameters?

In east and southern Africa some private ranch owners are corralling (hereafter kraaling) cattle overnight for short periods (for example, seven days) in natural rangelands to create nutrient enriched hotspots which are attractive to large herbivores. However, the effect of season and time after kraal use (alt. age of nutrient enriched hotspots) on large herbivore use of these sites has not been examined. We collated the number of large herbivore sightings per day from camera traps during wet, early and late dry season in nutrient enriched hotspots of varying ages (1, 2, 3 and 4 years) and surrounding vegetation. In addition, above ground grass biomass and height in nutrient enriched hotspots was compared to that of the surrounding vegetation. Furthermore, we tested if repeated grazing in nutrient enriched hotspots stimulated grass compensatory growth. Large herbivore use of nutrient enriched hotspots was similar during wet, early and late dry season. Time after kraal use had a significant effect on mixed feeders (impala and African savanna elephant) utilization of nutrient enriched hotspots but not grazers (zebra and warthog) and browsers (giraffe and greater kudu). Both impala and African savanna elephants mostly used nutrient enriched hotspots one year after kraal use. Aboveground grass biomass and height were higher in surrounding vegetation than in nutrient enriched hotspots. Repeated clipping (proxy for grazing) resulted in compensatory aboveground grass biomass in nutrient enriched hotspots, which declined with time after kraal use. We concluded that nutrient enriched hotspots created through short duration overnight kraaling were important foraging sites for large herbivores.

Ruminal Digestibility and In-Vitro Methane Emissions of Native Plant Species in Subtropical Rangelands

Enteric methane (CH4) emissions from livestock represent a significant agricultural source of greenhouse gas worldwide. The aim of this study was to determine the effect of plant species and season on nutritional value and methanogenic potential of Florida native rangelands. Treatments consisted of a 4 × 2 factorial arrangement of plant species (creeping bluestem [Schizachyrium scoparium var. stoloniferum {Nash} Wipff], lopsided Indiangrass [Sorghastrum secundum {Elliott} Nash], maidencane [Panicum hemitomon Schult.], and saw-palmetto [Serenoa repens {W. Bartram} Small]) and season (summer or autumn) distributed in a randomized complete block design with four replicates. Samples were analyzed for crude protein (CP), neutral detergent fiber, in-vitro CH4 production, and in-situ ruminal digestibility. The greatest digestive matter (DM) effective degradability was observed in the summer for creeping bluestem (422 g kg−1), followed by lopsided Indiangrass (379 g kg−1), maidencane (380 g kg−1), and saw-palmetto (250 g kg−1). The DM effective degradability decreased from summer to autumn for all species, except saw-palmetto. Maidencane had the greatest CP effective degradability in the summer (491 g kg−1), followed by lopsided Indiangrass (350 g kg−1), creeping bluestem (279 g kg−1), and saw-palmetto (170 g kg−1); however, lopsided Indiangrass and maidencane decreased CP effective degradability from summer to autumn. There was no difference in CH4 production among creeping lopsided Indiangrass and maidencane (mean of 7 mg g−1 DM), and saw-palmetto had the least CH4 emissions (2 mg g−1 DM). Grazing lopsided Indiangrass and maidencane in the summer was an effective strategy to optimize the use of native plant species with greater nutrient digestibility than autumn. Management practices intended to increase rangeland productivity, and the proportion of native grass species relative to saw-palmetto are expected to increase CH4 production. Further research is warranted to evaluate the impacts on rangeland management on animal performance and greenhouse gas balance.

Development of a growing degree-day model to estimateLinaria vulgarisshoot emergence and prospects for improving biological control efforts

AbstractYellow toadflax (Linaria vulgarisMill.; Scrophulariaceae) is an invasive herbaceous perennial weed of agricultural and natural habitats throughout North America. In pastures or native rangelands, use of biological control is an attractive option, particularly if the agent can be established quickly.Rhinusa pilosa(Gyllenhal) (Coleoptera: Curculionidae), a stem-galling weevil, was first released in Canada in 2014 to evaluate its potential to controlL. vulgaris.Rhinusa pilosarequires young, vigorously growing shoots to establish. Ability to estimate when adequate shoots will be available could inform release timing, thus improving establishment success. There is currently no growing degree-day (GDD) model forL. vulgaris. Our main objective was to develop a GDD model for the emergence ofL. vulgarisshoots and discuss the utility of such a model in relation to the establishment ofR. pilosain Nova Scotia. Four sites containing five randomly placed 1-m2quadrats were monitored for the emergence ofL. vulgarisshoots twice weekly in spring to summer 2017 and 2018 by recording number of shoots and shoots with flower buds. A GDD (Tbase2 C) model for shoot emergence ofL. vulgariswas developed and validated using independent shoot emergence data. Shoots emerged in the spring between 124 and 244 GDD with 90% of all shoots emerged between 681 and 1,117 GDD. Model estimation for the initiation of shoot emergence was 74 GDD, with 10%, 50%, and 90% shoot emergence estimated to occur at 179, 409, and 811 GDD, respectively.Rhinusa pilosaadults were released in 2016 (three sites) and 2017 (one site), and number of shoots with galls was recorded. Galls were observed in all three sites in 2016 and in three of the four sites in 2017, with none found in 2018. Timing of release and soil moisture are discussed as factors affecting establishment ofR. pilosain Nova Scotia.