Native Rangeland Research Articles

PSI-38 Relationship between body condition score, claw set, and foot angle in Angus and Red Angus beef cows grazing native annual-grass rangeland in northern California

Abstract Evaluating the structure of beef cows, especially when replacement females are being selected, has great emphasis on production goals, particularly longevity of the female. Two structure traits that are important when evaluating beef cattle are claw set and foot angle, yet the relationship between body condition scores (BCS), claw set, foot angle and year of age has not been extensively investigated. The objective of this study was to determine the relationship between BCS, claw set and foot angle in Angus (n = 40) and Red Angus (n = 19) beef cows grazing irrigated pasture and annual-grass rangeland in northern California. Traits were collected 44 d post-weaning and included BCS, claw set, and foot angle. Claw set and foot angle were collected using the scale of the American Angus Association (e.g., scale = 1–9). Spring-calving beef cows were under similar management. At time of trait collection cows were grazing irrigated pasture (CP: 38%, and NDF: 49.2%, on a DM basis). Data were analyzed using ANOVA and Pearson correlation. Fixed effects were claw set, foot angle and breed, and respective interactions. Body condition score was related to foot angle scores (r = 0.38; P < 0.01). Claw set was related to foot angle scores (r = 0.30; P < 0.05). Results showed BCS was not different among breeds, claw set, or year of age (P > 0.05). No relationship was detected among BCS and claw set. Interaction terms were not significant (P > 0.05). Cows with acceptable foot angle had lower BCS than unacceptable cows (5.86 ± 0.15 vs. 6.72 ± 0.21 BCS). Results indicate that BCS and foot angle are related. Further research to investigate effect of BCS on differences of foot angle is warranted.

PSIV-20 Evaluation of calf performance when cows grazing native rangeland are vaccinated for bovine viral diarrhea virus and infectious bovine rhinotracheitis using either a modified live or killed vaccine

Abstract Bovine viral diarrhea virus (BVDV) is a pathogen associated with gastrointestinal, respiratory, and reproductive diseases of cattle worldwide. Vaccination of cattle with antivirals have proven effective to reduce instances of BVDV. However, vaccination protocol adoption by producers and animal response to vaccination varies. The objective of this study was to determine if administration to the dam of a modified-live viral vaccine (MLV) or killed viral vaccine (KV) would impact the growth and rumen fermentation end products of the calf. The hypothesis for this study was that calves from dams vaccinated with MLV would have improved performance. Calves (n=20) born to dams that received either MLV or KV over the course of their lifetime, were housed on rangeland at the Corona Range and Livestock Research Center in Corona, NM. Cow ruminal contents were collected at birth. Both cow and calf ruminal contents were collected at 7, 35, 63, and 205 d of age. Cow body condition score did not differ between treatments (P > 0.05) (average KV = 4.3 + 0.8 and MLV = 4.3 + 0.8) at calving. Additionally, calf birth (P =0.66) weight and weaning weight (P > 0.05) did not differ between dam vaccine type. At days postpartum x vaccine type interaction was not observed for calf ruminal pH (P = 0.20) and volatile fatty acid concentrations (P > 0.28). However, calf ruminal pH increased with age (P < 0.0001). Butyrate concentrations were least at 7 days of age (P = 0.0069). Therefore, we reject our hypothesis; calves born from dams receiving MLV do not have improved performance when compared to KV counterparts. Results indicate birth weight, weaning weight, pre-weaned calves pH, and volatile fatty acid concentration, are not impacted by dam’s vaccination type. However, impacts on calf immunity have not been evaluated and require further research.

PSI-35 Foot and hair shedding scores of crossbred cattle grazing native rangeland differ by age group

Abstract Structural soundness is crucial to improve productivity and longevity of beef cattle in rangeland landscapes. In addition, hair shedding scores are utilized to select for heat tolerant cattle. Thus, the objective of this study was to collect data indicative of cattle adaptability to extensive rangeland landscapes in the Cal Poly beef cattle herd. Three trained technicians assigned claw set, foot angle and hair shedding scores. All data were collected over a 2-day period (n = 3 ranch locations) and foot scores were only collected from females (n = 211) that were at least 1 year of age. Each female was assigned a score for foot angle and claw set (1–9, 5 being ideal). A hair shedding score was also allocated (1–5, 1 = 0% winter coat, 5 = 100% winter coat) to both cows and calves of dams assigned to different age groups. Cattle were retrospectively assigned to a group based on age (Young = 2–3 years of age, Moderate = 4–7 years of age, Old = 8+ years of age) and data were analyzed with the main effects of ranch location and cow age group. Ranch location had no impact (P > 0.05) on foot score or hair shedding score. Cow age group had a significant impact (P < 0.01) on claw set, with young cows exhibiting a lower and more ideal foot score. However, cow age had no effect on hoof angle (P = 0.23). Young cows had a greater (P < 0.001) hair shedding score than their counterparts. Calf hair shedding score was not different (P ≥ 0.23) among dam age groups or ranch locations. Thus, these data indicate that feet and leg structure is compromised as cows age, and younger cows with higher hair shedding scores may lack adaptability to heat stress.

PSI-33 Evaluation of calf performance when cows grazing native rangeland are vaccinated for bovine viral diarrhea virus and infectious bovine rhinotracheitis using either a modified live or killed vaccine

Abstract Bovine viral diarrhea virus (BVDV) is a pathogen associated with gastrointestinal, respiratory, and reproductive diseases of cattle worldwide. Vaccination of cattle with antivirals have proven effective to reduce instances of BVDV. However, vaccination protocol adoption by producers and animal response to vaccination varies. The objective of this study was to determine if administration to the dam of a modified-live viral vaccine (MLV) or killed viral vaccine (KV) would impact the growth and rumen fermentation end products of the calf. The hypothesis for this study was that calves from dams vaccinated with MLV would have improved performance. Calves (n = 20) born to dams that received either MLV or KV over the course of their lifetime, were housed on rangeland at the Corona Range and Livestock Research Center in Corona, NM. Cow ruminal contents were collected at birth. Both cow and calf ruminal contents were collected at 7, 35, 63, and 205 d of age. Cow body condition score did not differ between treatments (P > 0.05) (average KV = 4.3 + 0.8 and MLV = 4.3 + 0.8) at calving. Additionally, calf birth (P =0.66) weight and weaning weight (P > 0.05) did not differ between dam vaccine type. At days postpartum x vaccine type interaction was not observed for calf ruminal pH (P = 0.20) and volatile fatty acid concentrations (P > 0.28). However, calf ruminal pH increased with age (P < 0.0001). Butyrate concentrations were least at 7 days of age (P = 0.0069). Therefore, we reject our hypothesis; calves born from dams receiving MLV do not have improved performance when compared to KV counterparts. Results indicate birth weight, weaning weight, pre-weaned calves pH, and volatile fatty acid concentration, are not impacted by dam’s vaccination type; however, impacts on calf immunity have not been evaluated and require further research.

Spatial analysis of rangeland's vegetation intensity as related to selected physical soil variables over ABQAIQ municipality of Saudi Arabia.

Through most of the natural rangelands of Saudi Arabia, overgrazing, sand drifting, and off-road vehicles driving are almost the major contributing factors that lead to vegetation damage and land degradation in natural landscapes. The current study aimed at examining the dynamic nature of Abqaiq rangelands' vegetation, generating a vegetation intensity map, and investigating possible impacts caused by the spatial variability of obtained soil texture, sand content (%), and the derived available water capacity (DAW capacity (%)) on the intensity distribution of vegetation cover. Ordinal-nominal correlation type and spatial autocorrelation processes were adopted throughout the study to analyze the spatial correspondences as well as the interrelated patterns of the given variables. The resultant correlation between vegetation and soil texture (ordinal versus nominal variables) has yielded a significant (p-value < 0.001) relevancies, where, silt loam texture class, in particular, has proven to have the most correlated values to the most intensive vegetation habitats, where 5%, 35%, and 28% of the silt loam class were occupied by 80%, 60%, and 40% of vegetation intensities, respectively. Whereas, for the continuous variables, correlation outcomes have achieved a substantial negative spatial autocorrelation concerning vegetation intensity and sand content percentage, revealing a total absence of green biomass over the sandy soils. Additionally, vegetation intensity versus DAW capacity percentage significantly yielded a positive autocorrelation, revealing a high clustering of green biomass cover that associates with high clustering of high-water capacity soils. The autocorrelation strength identifier (Morn's I), produced an approximate value of 0.3 with a pseudo p-value of 0.001, for both relationships. The findings of this study would help researchers and relative authorities to grasp the reasons, consequences and behaviors of rangeland flora, considering Abqaiq's area as an example.

Reproductive traits in four spontaneous Pappophorum vaginatum populations in arid Argentina

Arid zones, where native rangelands are common, are essentials for millions of people livelihood. These areas support 50% of the world's livestock and are where 44% of the world's food is grown. In rangelands of Central Argentina, Pappophorum vaginatum is basically the unique, warm-season perennial grass species palatable to grazing livestock. Our major objective was to determine variability in reproductive characteristics among four spontaneous, overgrazed populations (i.e., P1, P2, P3, P4) of that species to identify promissory materials for domestication. Studies were conducted during three consecutive growing seasons within the southwestern part of the Phytogeographical Province of the Monte, in southwestern Buenos Aires, Argentina. Measured reproductive characteristics were related to flowering initiation, seed production and natural reseeding potential. Significant differences were found for flowering initiation and natural reseeding potential, but not for viable anthecia per plant among the four populations of P. vaginatum. This species fructified from the beginning to the end of the studied growing seasons with a great anthecia production per plant. The light weight of these anthecia and their awns would favor a great wind dispersal and most likely the establishment of new seedlings of P. vaginatum. This suggests that sexual reproduction might have a relatively greater importance than asexual reproduction (i.e., tillering) in the persistence of the overgrazed P. vaginatum in the plant communities of the studied region. Selection of plant materials with a late flowering initiation will allow to extend the forage production of a better quality. The variability among and within populations found on this study supports the idea that would be promissory to start selection programs to obtain improved germplasm to reincorporate to grasslands of the south of the Phytogeographical Region of the Monte (Argentina) not only to increase livestock production but also to recover and maintain biodiversity.

Dormant season grazing on northern mixed grass prairie agroecosystems: Does protein supplement intake, cow age, weight and body condition impact beef cattle resource use and residual vegetation cover?

Dormant season livestock grazing reduces reliance on harvested feeds, but typically requires protein supplementation to maintain animal performance. Individual variation in supplement intake can impact animal performance; however, it is unknown if this variation leads to individual or herd-level effects on grazing behavior, resource utilization, and grazing impacts to native rangelands. To examine effects of protein supplementation on dormant season cattle resource use and, subsequently, post-grazing habitat conditions, we examined cattle grazing behavior, resource utilization and biomass removal of vegetation on a native rangeland in Montana. A commercial herd of 272 (yr 1) and 302 (yr 2) cows grazed a 329-ha rangeland pasture from November to January. Intake of a 30% crude protein supplement was measured for each individual. Five individuals within each of six age groups were equipped with GPS collars. Time spent grazing declined with supplement intake ( = −0.05 ± 0.02; P < 0.01). Distance traveled per day had a positive asymptotic association with supplement intake ( = 0.35 ± 0.09; P < 0.01). On average, resource utilization by cattle grazing dormant season forage decreased with terrain ruggedness ( = −0.09 ± 0.03), but was unrelated to aspect, temperature and wind speed. Notably, we observed high individual variability in resource utilization for elevation, distance from supplement and water. A post-hoc analysis suggested that individual attributes (age, body weight, supplement intake) influenced cattle resource use. At moderate stocking rates, dormant season livestock grazing did not affect residual vegetation conditions (P values > 0.22). However, residual cover of forbs and litter increased with relative grazing intensity ( = 1.04 ± 0.41; = 3.06 ± 0.89; P ≤ 0.05). In summary, high individual variability in grazing resource utilization of cattle suggests individual-level factors could be the dominant drivers in grazing behavior and landscape use.

Do haematological profiles of cows in drought prone areas differ with conformation?

Aim of study: Severe and frequent droughts have resulted in loss of thousands of rangeland cattle worldwide. The objectives of the current study were to assess the reduction in dimensionality of seven conformation traits and to determine the relationships between extracted constructs and haematological parameters associated with drought resilience in beef cows.Area of study: Muzarabani district, Zimbabwe.Material and methods: Fifty multiparous Mashona cows kept on natural rangelands were used. The collinearity of seven conformation traits of the cows was reduced using principal component analysis. The relationships between the principal components and hematological profiles of the cows were subsequently determined using regression analysis.Main results: First extracted principal component described body capacity (body depth, flank circumference, chest girth). The second component described the frame size (stature and body length) of the cows and the third component was comprised of sheath height and dewlap size. Cows characterised by deep bodies, large flanks and chest girths had low percent haematocrit (HCT), mean capsular haemoglobin concentration (MCHC) and red cell distribution (RDW) (p&lt;0.05). Small-framed cows were associated with low mean platelet volume (MPV), HCT, MCHC and RDW levels in blood (p&lt;0.05). As principal component 3 of conformation traits increased, white blood cell count, mean corpuscular volume, RDW and MPV decreased (p&lt;0.05).Research highlights: Small-framed cows with large thoracic capacities, large dewlaps and belly bottoms far away from the ground surface are able to maintain haematological normalcy under rangelands in drought prone areas.

Characterizing Temporal Ecophysiology for Herbicide Management of Huisache (Acacia farnesiana [L.] Willd.)

Huisache (Vachellia farnesiana [L.] Wight & Arn.) is a woody species native to the western hemisphere that can invade a variety of native rangeland habitats around the world. In South Texas, it is native yet increasing in density and range while displacing more desirable forage plants, and because it resprouts prolifically it has been difficult to control. We therefore attempted to characterize optimal timing and environmental conditions for herbicide control. We collected weather data in four huisache-invaded pastures along the Texas Coastal Bend and recorded the average huisache phenological stage at those pastures each month. We also analyzed root crown total nonstructural carbohydrate (TNC) and huisache mortality resulting from herbicide treatment each month between April 2012 and November 2014. Huisache mortality and TNC data were analyzed using a randomized complete block analysis of variance, with post hoc tests to separate means; Akaike's information criterion determined best-fit models for mortality data. Root crown TNC increased during May, August, and December, indicating downward translocation and the potential for increased mortality of treated plants. Actual mortality was greatest during the months of May, September, October, and November. The best fit model for mortality was a sixth-order polynomial function of mortality versus month; when month was removed as a model factor, the best fit model was a quadratic function of soil temperature (peaking at ≈24.5°C), combined with a quadratic function of phenology (highest at full canopy stage). These results indicate that huisache is best treated with chemicals when soil temperature is near 24.5°C and during the full canopy stage. In the coastal plains of South Texas these variables coincide with two windows of optimal mortality for huisache treatment: May and September−November.

Plantations d’&lt;em&gt; Atriplex canescens &lt;/em&gt; en vue de la restauration des parcours dégradés en steppe algérienne

La steppe algérienne est le milieu d’élevage du mouton par l’exploitation de ses parcours. Dans sa partie aride, la vulnérabilité du milieu est aggravée par une exploitation principalement pastorale de plus en plus intense durant ces dernières décennies. Cette tendance régressive est caractérisée par une baisse dela productivité fourragère et les espèces pérennes sont les plus touchées. L’Etat algérien a mis en oeuvre un programme d’aménagement des espaces steppiques très dégradés à travers la plantation d’espèces végétales résistantes et productives de biomasse comme Atriplex spp. L’objectif de ce travail a été d’estimerla productivité pastorale de quelques stations réhabilitées par la plantation d’Atriplex canescens, comparativement aux parcours naturels pâturés. Les résultats ont montré une amélioration du recouvrement végétal (de 49 % à 60 %) et de meilleures valeurs pastorales (phytomasse, productivité, valeur énergétique et charge pastorale). Sur les zones réhabilitées une productivité énergétique et protéique de 604 unités fourragères lait / ha/an et 29 kg de matière sèche / ha/an, et une charge pastorale de 1,51 unité ovine / ha/an ont été enregistrées, alors que sur les parcours naturels dégradés ces valeurs ont été respectivement de 14 UFL, 0,422 kg MS/ha/an, et 0,03 unité ovine / ha/an. Les stations naturelles sont surexploitées et tendent vers un état de dégradation sévère de la végétation et des sols steppiques. A moins de restaurer ou de réhabiliter les parcours steppiques, leur capacité de productivité pastorale sera fortement réduite.

Habitat selection of female sharp-tailed grouse in grasslands managed for livestock production.

Habitat selection links individual behavior to population abundance and dynamics, so evaluation of habitat selection is necessary for conservation and management. Land management can potentially alter both the structure and composition of habitats, thus influencing habitat selection and population size. Livestock grazing is the dominant land use worldwide and, while overstocking has been linked to the decline of many wildlife species, properly managed grazing could improve habitat quality and maintain native rangeland habitats. We evaluated breeding season habitat selection of female sharp-tailed grouse, an indicator species for grassland ecosystems, in relation to grazing management and landscape features in eastern Montana and western North Dakota. At broad spatial scales, females selected for multiple landscape features, including grassland, but exhibited no selection for either landscape or management variables when selecting habitat at smaller spatial scales. Females selected for pastures managed with rest-rotation grazing when choosing a home range, but selection did not equate to improved fitness. Moreover, we observed strong individual variation in both home range size and third-order habitat selection. While the high variability among individuals makes specific management recommendations difficult, selection for grassland habitats at broad scales suggests that strategies that maintain intact native rangelands are important for the conservation of sharp-tailed grouse.

Development of a soil quality index for characterizing effects of land‐use changes on degradation and ecological restoration of rangeland soils in a semi‐arid ecosystem

AbstractThe aim of this research was to study the influence of land‐use changes on degradation and ecological restoration of rangeland soils by quantifying 15 soil attributes and the subsequent development of a soil quality index (SQI). Soil properties were determined to establish a minimum data set (MDS) for the development of an overall weighted additive SQI. The soil attributes were measured on samples (0 to 15 and 15 to 30‐cm depths) collected in undisturbed rangelands, cultivated rangelands, and restored rangelands following cultivation abandonment for 12 or 45 years in a semi‐arid ecosystem, Central Iran. The selected MDS indicators consisted of the mean weight diameter (MWD), total nitrogen (TN), microbial respiration (MR), and alkaline phosphomonoesterase activity (ALP). Overall, soil aggregation, N content, microbial activity, and ALP activity were found to be the key indicators contributing considerably to the SQI of rangeland ecosystems. Soil MWD had the highest contribution (31%) to the estimated SQI values, followed by TN (27%), MR (22%), and ALP (21%). Results indicated a clear difference in soil quality among the common land uses with a significant decline of SQI after conversion of native rangelands (0.80) to croplands (0.53). Restored rangeland soils were characterized by a higher value of SQI (0.63–0.73) as compared with cultivated rangelands (0.53). This suggests a good recovery of soil capacity and functions after the abandonment of cropping activity in previously cultivated rangelands. Vegetation restoration and plant productivity appeared to be the major driver of improved soil quality of the abandoned croplands in these rangelands. Our SQI tool could be useful to determine the success of agricultural abandonment and ecological restoration of rangeland soils in the studied semi‐arid environment.

Surveillance of Baladi Goat Feeding Behavior in Response to a Mediterranean Natural Rangeland Evolution

The Lebanese Baladi goat dairy production sector suffers from food availability problems due to the dependence on natural rangelands and the scarcity of crop residues and forage pastures, leading to lower production. Thus, the nutritional values of the pastures were evaluated in an observational study where 48 Baladi lactating goats were selected and kept within a farm in Qâa er Rîm located in the region of Zahleh, Lebanon. Animal responses in feeding behavior were measured on four different circuits of natural rangelands (NR1, NR2, NR3, and NR4) surrounding the farm site, during a period of ≈75 d (from April to mid-June). Observations and measures consisted of evaluating the rangeland’s botanical composition, selective feeding and analysis of forage nutritional values, recording of daily foraging dynamic, and estimation of daily intake. Natural rangelands revealed a large botanical diversity that changed according to season and altitude: From NR1 to NR4, as summer season advanced and animals were moved to higher altitudes, bushes increased, whereas grasses retreated. In parallel, mean diet nutritional value decreased; dry matter (DM) content increased, as well as acid detergent fiber and neutral detergent fiber contents, while crude protein levels decreased. The animals, however, adapted their feeding dynamics on the rangelands accordingly: With the advancement of summer time, total duration of grazing day was increased in order to compensate for longer resting periods at noon and longer walking periods in higher altitudes, without a decrease in total feeding duration. On the other hand, animals were able to adjust their feeding regimen to the available plant species by increasing their daily intake of 0.56 kg/d between NR1 and NR3 and by substituting grasses with shrubby species; a shift from 25% to 28% to 53% to 54% DM in the animals’ diet. These adaptive behavioral responses explain the capacity of Baladi goats to survive in their harsh environment and even tolerate feeding perturbations.

Beef cattle production impacts soil organic carbon storage

Grazing of natural rangeland and seeded pasture is an important feeding strategy for the Canadian beef cattle industry. As a consequence, beef cattle population has a direct influence on the proportion of land base maintained as perennial forage, which in turn changes soil organic carbon (SOC) stocks. We examined historical relationships between the net change in SOC resulting from perennial/annual crop conversion and beef cattle populations. We observed strong negative linear relationships, both regionally and nationally, between the population of beef cattle and the estimated change in SOC (negative sign indicating soil C sink) resulting from the conversion of annual crops and vice versa. These relationships indicate that as beef cattle population declines there is a corresponding loss of SOC resulting from a reduction in the relative proportion of perennial to annual crops on the landscape. The annual C loss resulting from land use conversion was roughly equivalent to 62% (±13%) of the combined enteric and manure annual emissions of CH4 and N2O [(1400 (±440) kg CO2 eq head−1 yr−1] resulting in net greenhouse gas emissions of 850 (±360) kg CO2 eq head−1 yr−1. These results highlight the importance of an integrated analysis that considers land use conversion and its impact on SOC when assessing the environmental footprint associated with beef cattle production.

A toxic grass Achnatherum inebrians serves as a diversity refuge for the soil fungal community in rangelands of northern China

In many grasslands under grazing pressure, unpalatable plants have become abundant and these areas are refuges for plant diversity. We hypothesize that unpalatable plants may also serve as refuges for soil microbes. We tested this hypothesis by investigating soil fungal diversity and community composition, soil properties, and plant parameters in areas dominated by the unpalatable drunken horse grass (Achnatherum inebrians), and areas without this toxic grass, in three types of natural rangelands in northern China. Our results showed that the areas dominated by A. inebrians had a higher fungal diversity, higher microbial biomass, higher abundance of plant pathogens in soil, and higher plant biomass than areas that did not contain A. inebrians. Soil fungal community composition was positively correlated with plant community composition across the three study sites. Fungal diversity and microbial biomass were positively correlated with higher plant biomass. Abundance of soil plant pathogens was positively correlated with coverage of A. inebrians. The results indicated that plant community composition significantly correlated with soil fungal community composition, and refuge effects of A. inebrians drive higher fungal diversity, microbial biomass and abundance of plant pathogens in the soil. Increased abundance of A. inebrians potentially has considerable effects on the soil fungal community in grasslands.

Similar Bird Communities Across Grazing Systems in the Nebraska Sandhills

ABSTRACTMuch of the remaining native rangeland in the Great Plains in the United States is privately owned and managed for beef production, and this single priority for land use may be contributing to declining avian biodiversity through a loss of structural heterogeneity. One proposed solution is to use multiple grazing systems across ranches, under the assumption that this approach will increase heterogeneity of vegetation structure and avian diversity across the landscape. We tested the relationship between grazing systems and avian diversity in the Nebraska Sandhills during 2014 and 2015 on a landscape that included 11 management units containing 5 different grazing systems. We used multivariate models to examine the relationship of bird diversity and communities to grazing systems at the management unit scale, and we used simulations to combine empirical data from ≥1 grazing system into virtual landscapes to test the hypothesis that multiple grazing systems would result in greater heterogeneity. The 5 most common avian species made up 84% of observations (28 species), and songbird richness was 5–6 species/7.06 ha at 53% of our plots. Variation in each of the diversity measures (Shannon diversity range = 0.41–2.2, Simpson's diversity range = 0.24–0.88) was best explained by the previous dormant season's stocking rate, and richness declined by about 1 species/plot with an increase in 1 animal unit month (AUM)/ha. Songbird community structure showed the most variance between management unit, but grazing system explained little community variation. None of the simulated landscapes consistently had greater structural heterogeneity of visual obstruction reading, litter depth, and cover of bare ground than others, and there was a limited level of heterogeneity overall in the simulated landscapes. In contrast to our predictions, a variety of grazing systems did not increase heterogeneity of vegetation structure across the landscape. Thus, conservation practitioners should encourage the use of other strategies to create structural heterogeneity, such as prescribed fires and extreme stocking rates, which will support a diverse grassland songbird community (i.e., a greater variety of bird species) across the landscape. © 2020 The Wildlife Society.

Belowground biomass decomposition is driven by chemical composition in subtropical pastures and native rangelands

AbstractLitter decomposition, particularly from belowground pools, is a key process controlling the flow of nutrients and the sustainability of native and cultivated grazinglands. This study evaluated in situ belowground decomposition of saw‐palmetto (Serenoa repens [W. Bartram] Small) and bahiagrass (Paspalum notatum Flügge; BG), which corresponded to the predominant plant species in native and cultivated pastures in the southeastern United States. Belowground biomass decomposition (180 d) was estimated using the litterbag technique during the summer and winter. Season showed no effect on belowground decomposition. Decomposition followed a double exponential model (P ≤ .01) and was greater for BG than for native rangeland (NR) (−0.0008 and −0.0001 g g−1 d−1, respectively; P = .0035), resulting in less remaining material at the end of incubation for BG (74% compared with 93% for NR; P ≤ .002). Greater decomposition in BG occurred due to more favorable chemical composition than NR, namely greater initial N concentration (17 and 8 g kg−1 organic matter for BG and NR, respectively) and lower initial C/N ratio (29 and 65 for BG and NR, respectively), lignin/N ratio (13 and 54 for BG and NR, respectively), and C/P ratio (407 and 1,327 for BG and NR, respectively). Despite the differences in initial C/N ratios, remaining N was similar between BG and NR at end of incubation (96 and 84%, respectively; P = .3711). Land use intensification in grazinglands, in particular conversion of native rangelands to cultivated pastures, can have major impacts on belowground decomposition and on the biogeochemical cycle of nutrients in these ecosystems.

MUŞ İLİ KIYIBAŞI KÖYÜ MERASININ FARKLI YÖNEYLERİNİN BOTANİK KOMPOZİSYONUNUN BELİ

This study was carried out in order to determine the botanical composition of a natural rangeland area in Kiyibasi Village, Central District of Mus. In this study; dominant species in rangeland areas, plant-covered area, botanical composition, frequency and grazing capacity were investigated. In the study area, 55 genera belonging to 21 plant families and 66 taxa belonging to these genera were found and 11 of these species were grasses, 10 were legumes and 45 were other family plants. The majority of other family plants were found to be Asteraceae, Lamiaceae, Boraginaceae and Aranunculaceae. While the ratio of rangeland-covered area is 85.8%, the ratio of grasses in the botanical composition is 39.37%, the ratio of legumes is 15.15% and the ratio of other family plants is 33.55%. Grasses were found mostly in the East (46.6%) and in the same group statistically in the North, while other family plants were found in the West (41.2%) and in the same group in the South and East. The most common species in the rangeland were found to be Aegilops umbellulata (50.56%), Minuartia hamata Mattf. (23.75%), Medicago minima L. (13.00%), Stipa lagascae L. (10.75%) and Festuca rubra (10.50%). The grazing capacity of the rangeland was found as 51 Animal Units. As a result of this study, it was concluded that excessive, early and irregular grazing was done in this rangeland as in other rangelands in our country, therefore the yield of rangeland examined was very low, other family plants were dominant in vegetation and therefore the rangeland was weak.

Distribution and abundance of Aphanomyces euteiches in agricultural soils: effect of land use type, soil properties, and crop management practices

Aphanomyces euteiches is a soil-borne pathogen that causes root rot in susceptible pulse crops. Although widespread across Canada, A. euteiches was not reported in Saskatchewan until 2012. The distribution of this pathogen across the Canadian prairies is unknown and it is unclear whether it is native to the region. The objective of this study was to conduct a survey of A. euteiches across the major agricultural soils of Saskatchewan, Canada to determine its distribution and to assess the relative importance of factors related to its distribution and possible spread across the province. Soil samples were collected from lentil and pea fields and their associated roadside ditches, as well as from native and tame rangelands. Soil samples were analyzed using a quantitative polymerase chain reaction (qPCR) assay to detect and quantify the presence of A. euteiches. In addition, root rot severity was assessed on affected pea and lentil plants, and the physical and chemical properties of the soils were measured. A. euteiches was present across all land use (i.e., annual cropland, roadside ditches, and rangeland) and soil types in Saskatchewan. A. euteiches abundance was highest in samples collected from annually cropped fields. Within annual cropland, A. euteiches abundance was higher in pea fields than lentil fields. Soil moisture, total and organic carbon, and total nitrogen were positively correlated to A. euteiches abundance in field and roadside soils. Based on this survey, A. euteiches is wide-spread across all the major agricultural regions of Saskatchewan and is not limited to specific soil or land use types. The frequent detection of A. euteiches in native rangeland indicates it is likely native to Saskatchewan. The significant relationship between A. euteiches gene abundance and disease severity in pea fields indicates that the qPCR assay may be a useful indicator for predicting the potential for certain agricultural soils to cause A. euteiches root rot in pea crops.

Resiliency of Native Mixed-Grass Rangelands and Crested Wheatgrass Pasture Lands to Spring Wildfire

Previous research has suggested that prescribed fire will become more necessary in the northern Great Plains of the United States as woody encroachment and invasive plant species cover increase. Prescribed fire will likely become a more frequent management strategy to mimic natural processes in grasslands—a combination of fire and grazing. However, the amount of research on fire is somewhat lacking since the 1980s, with few land managers and producers willing or able to use fire in the western half of the northern Great Plains. We evaluated the impact of a wildfire in northwest South Dakota on two ecological sites (sandy and shallow sandy) and two vegetation types (native rangelands and crested wheatgrass pasture lands) to gain more insights into potential fire effects by comparing burned with adjacent nonburned sites, as well as comparing sites 5 yr prefire and 4 and 16 mo post fire. We collected data on plant species composition, bare ground, and biomass production. We did not detect any negative effects to the overall plant community, but crested wheatgrass did increase on some burned sites 16 mo post fire. The most prominent difference between burned and nonburned sites was the increase in bare ground and reduced basal litter on burned sites, but these changes were undetectable 16 mo after fire. Our results suggest mixed-grass prairies in the northern Great Plains are resilient to fire, and prescribed fire could be an appropriate management strategy when applied at the correct spatial-temporal scale and fire prescription. When specific management strategies, like fire, are perceived as negative, research has the potential to overcome perception and provide more context for land managers and producers on the conditions that affect management strategies.