Grazed Site Research Articles

Peripheral Population Status and Habitat Suitability Assessment of the Kiang (Equus kiang) on the Eastern Tibetan Plateau

Shiqu County, Sichuan Province, forms the eastern edge of the distribution area of the kiang (Equus kiang). It is important to assess the population and habitat status of peripheral populations, as these play a significant role in the development of conservation strategies for kiangs. Based on field transect data collected from July to August 2023, this study predicted the suitable habitat distribution of kiangs in Shiqu County using a MaxEnt model and estimated the population size and density using the ‘Distance’ package. Additionally, it analyzed the responses of the group size of kiangs to environmental factors in Shiqu County. The results showed that the area of suitable habitat for kiangs is 3402.45 km2, accounting for 13.51% of the total area of Shiqu County. The estimated population was 1395.00 ± 272.20, with a population density of 0.41 ± 0.08/km2. Additionally, the group size of kiangs was significantly positively correlated with the distance from the road and grazing site. The distance from the grazing site, elevation, and temperature annual range are the main environmental factors affecting the distribution of kiangs. This study initially revealed the peripheral population Status and suitable habitat of the kiang on the eastern Tibetan Plateau, and the potential threat of grazing interference and road obstruction. The research results can provide a scientific reference for the population and habitat protection of kiangs in this area.

Responses of plant and microbial C:N:P stoichiometry to livestock removal

Livestock removal (LR) is considered an effective strategy for recovering ecosystem functions in degraded grasslands. Carbon (C), nitrogen (N), and phosphorus (P), as well as their ratios in plants and microorganisms, act as key regulators of ecosystem stability and nutrient limitation during grassland succession. However, few studies have comprehensively evaluated plant and microbial nutrient limitations through C:N:P stoichiometry following LR over different durations. Here, our study explored the C, N, P contents, and C:N, C:P and N:P ratios of green and senescent leaves, microbial biomass and extracellular enzymes after 33 years of LR on the Loess Plateau, China. The results showed that LR increased the C, N, and P contents of plant and microbial communities. LR (>26 years) enhanced C, N, P contents of green leaves by 364.7 %, 232.2 %, 134.6 %, and C, N, P contents of senescent leaves by 164.8 %, 230.8 %, 86.3 %, respectively. LR also increased plant C:P and N:P ratios and the P reabsorption efficiency, indicating that the plant communities shifted from N to P-limitation during grassland restoration. Compared with the grazing sites, LR26 increased C, N, P contents, C:P and N:P ratios of soil microbial biomass, whereas reduced soil N-acquiring enzyme activity and enzymatic N:P ratio, indicating that the microbial community experienced higher P limitation than that of grazing sites. Plant and microbial communities showed strong plastic relationships with soil resource. Vegetation cover and productivity played strong roles in altering the plant and microbial C:N:P stoichiometry following LR. These findings indicate that long-term LR (>26 years) will exacerbate plant and microbial P limitation during grassland succession.

Effects of Grazing on Plant Diversity and Their Carbon Stocks in Different Types of Grasslands

With the drying and warming of the climate and irrational grazing, various types of grasslands in Inner Mongolia have been degraded to different degrees, and different management modes will inevitably affect the plant diversity and vegetation carbon stock of soil grasslands. To clarify the changes and influencing factors of plant diversity and carbon stock in different types of grasslands under different management modes, plant species composition, aboveground biomass, and vegetation carbon were analyzed based on 18 sentinel monitoring stations across three different types of grasslands in Inner Mongolia. The results showed that grazing increased the dominance of typical grassland and desert grassland, whereas meadow grassland decreased, and the evenness index and Shannon Wiener diversity index increased less in meadow grassland and desert grassland. Grazing decreased graminaceous biomass in meadow grassland and typical grassland, whereas it increased in desert grassland. Above-ground vegetation and below-ground root carbon stocks were much higher than those in grazing areas, 1.5 and 1.2 higher, respectively, but vegetation carbon stocks in long-term grazing sites were significantly lower than those in short-term grazing. Further, the structural equations showed that the effects of geographic location, climatic factors, and soil factors on the biomass and vegetation carbon stocks of the three grassland types differed significantly. The results can provide a reference for the ecologically sustainable development of grassland and the optimization of management mode.

Tracking Free-Ranging Pantaneiro Sheep during Extreme Drought in the Pantanal through Precision Technologies

The Pantanal has been facing consecutive years of extreme drought, with an impact on the quantity and quality of available pasture. However, little is known about how locally adapted breeds respond to the distribution of forage resources in this extreme drought scenario. This study aimed to evaluate the movement of free-grazing Pantaneiro sheep using a low-cost GPS to assess the main grazing sites, measure the daily distance traveled, and determine the energy requirements for walking with body weight monitoring. In a herd of 100 animals, 31 were selected for weighing, and six ewes were outfitted with GPS collars. GPS data collected on these animals every 10 m from August 2020 to May 2021 was analyzed using the Python programming language. The traveled distance and activity energy requirements (ACT) for horizontal walking (Mcal/d of NEm) were determined. The 31 ewes were weighed at the beginning and end of each season. The available dry matter (DM) and floristic composition of the grazing sites were estimated at the peak of the drought. DM was predicted using power regression with NDVI (normalized difference vegetation index) (R2 = 0.94). DM estimates averaged 450 kg/ha, ranging from traces to 3830 kg/ha, indicating overall very low values. Individual variation in the frequency of use of grazing sites was observed (p < 0.05), reflecting the distances traveled and the energetic cost of the activity. The range of distances traveled by the animals varied from 3.3 to 17.7 km/d, with an average of 5.9 km/d, indicating low energy for walking. However, the traveled distance and ACT remained consistent over time; there were no significant differences observed between seasons (p > 0.05). On average, the ewes’ initial weight did not differ from the weight at the drought peak (p > 0.05), indicating that they maintained their initial weight, which is important for locally adapted breeds as it confers robustness and resilience. This study also highlighted the importance of the breed’s biodiverse diet during extreme drought, which enabled the selection of forage for energy and nutrient supplementation. The results demonstrated that precision tools such as GPS and satellite imagery enabled the study of animals in extensive systems, thereby contributing to decision-making within the production system.

Effects of livestock grazing on herbaceous species composition and biomass in the Simien Mountains National Park, Ethiopia

Abstract Simien Mountains National Park (SMNP) provides valuable ecosystem services. Despite its ecological values, the effect of livestock-free grazing on habitat quality has not been investigated. The present study aimed to examine how livestock grazing within the Simien Mountains National Park affects herbaceous plant diversity and biomass. The study was carried out from February 2019 to July 2019 in livestock-grazed and ungrazed sites. In each grazing site, ten transects with a length of 25 m were set monthly. Along each transect line, five temporary sample plots (1 m2) were established. For aboveground biomass estimation, grass and forbs were clipped from 0.25 m2 in every sample plot, whereas below-ground biomass was estimated from two soil core (diameter = 6.35 cm, depth =20 cm) samples in each transect. Species diversity and evenness were estimated using the Shannon-Wiener diversity and evenness index. A total of 43 plant species belonging to 20 families were identified. Aboveground biomass and below-ground biomass were significantly higher in ungrazed areas than in the grazed ones. Similarly, species diversity and richness were relatively lower in the grazed areas than in ungrazed areas. The study concluded that livestock grazing has affected the habitat by degrading the vegetation diversity and biomass production. Therefore, stakeholders should be encouraged to innovate appropriate grazing management technologies for the local livestock ranchers to support the conservation efforts of the park.

The impact of grazing on biodiversity and forest succession in the Brazilian dry forest region is constrained by non-equilibrium dynamics

The impacts of grazing on rangelands have historically been studied within the framework of the equilibrium model, which predicts significant impacts of grazing on ecosystems. However, in recent decades, studies have observed a non-equilibrium pattern, suggesting that abiotic factors play a primary role compared to grazing. These studies are primarily focused on rangelands, despite animal husbandry occurring in other biomes, such as seasonally dry tropical forests. Our study examines the influence of goat grazing on biodiversity and forest succession in the Brazilian dry forest (Caatinga). Considering its high interannual precipitation variability, we hypothesize a response that aligns with the non-equilibrium paradigm. We established a gradient of grazing intensity and history in areas at different stages of vegetation succession. A survey of tree - shrub and herbaceous species was conducted at each site and the biomass of both strata was quantified. Linear mixed models and Permanova were employed to assess differences in richness, composition, structure, and biomass among the areas. Our results suggest that grazing (history and intensity) and forest fallow age did not affect species richness, but only species composition. Low and high grazing intensity drive ecosystems toward similar compositions, which align with the non-equilibrium model predictions. Biomass in the herbaceous layer remained unaffected by grazing history, intensity, or forest fallow age, whereas woody biomass was influenced by grazing intensity in older forest fallows. Although trees in low-intensity grazing sites were significantly taller compared to those in other levels, overall, grazing did not disrupt the natural succession process. Older forest fallows exhibited greater diversity and higher basal area compared to new forest fallows, irrespective of grazing intensity. Our findings suggest that: a) grazing has minimal effects on biodiversity and biomass due to non-equilibrium dynamics, and b) with appropriate management, grazing can coexist with the conservation of the Caatinga.

Mammalian community responses in relation to anthropogenic disturbances and resource gradients in the shade coffee forest ecosystem of Southwestern Ethiopia

Understanding the effects of variation in resource availability and habitat disturbance on the ecology of mammals is vital for successful conservation management. In this study, we examined how human disturbances, resource availability and elevation gradients influence mammal assemblages in both managed coffee forest and natural forest of the Belete-Gera National Forest Priority Area, southwestern Ethiopia. We surveyed mammals using motion-detecting infrared camera traps in 90 locations for a total of 4142 camera days. We measured distance from main roads and settlements as disturbance factors, and distance from water sources, key grazing sites, and forest edges and woody plant diversity as resource variables. We assessed the mammal assemblages in coffee forest and natural forests using generalized linear models. Further, we used linear modelling to compare the relationships of mammal detection rates by feeding guilds and body size to resource variables. In total, we recorded 8815 videos identifying 23 different mammal species. The mammal assemblages in coffee forests were negatively associated with increasing distances from key grazing sites, water sources, and elevation. In contrast, the association with increasing distance from the road and woody plant diversity was positive. In addition, herbivores and large (25–200 kg) and very large (≥200 kg) mammals, were all negatively associated with increasing distance from the natural forest edges. With the conversion of natural forest to coffee forest and the intensification of coffee forest management, sustainable management of key grazing sites, water sources, and diverse woody plant species will be essential to the conservation of mammals. In addition, to ensure mammal conservation, adjacent natural forests around coffee forests should also be protected.

Arbuscular mycorrhiza and rhizosphere soil enzymatic activities as modulated by grazing intensity and plant species identity in a semi-arid grassland

Understanding the symbiosis of arbuscular mycorrhizal fungi (AMF) with plants in relation to soil nutrients and enzyme activities under different grazing intensities can be an important guide for the management and protection of semi-arid grasslands. The aim of the present study was to evaluate how the interaction of grazing intensity and plants shapes the composition of AMF communities and enzyme activities in a semi-arid grassland ecosystem in Iran. Sampling focused three dominant plant species (i.e., Salsola laricina, Artemisia siberia, and Stipa hohenackeriana) at sites with different grazing intensities. Soil chemical properties, enzyme activities, root colonization by AMF and AMF communities in the roots were evaluated. Potassium and nitrogen, as well as alkaline phosphatase and urease enzymatic activities were significantly increased at the heavily grazed site, whereas root colonization by AMF was reduced by the high grazing intensity. In addition, AM fungal root colonization is dependent on the host plant species and easier to measure as a sensitive indicator of sustainable grazing. Neither plant species nor grazing intensity affected AM fungal diversity in roots, which could be due to the overall low phylogenetic diversity of AMF in the grassland and the lack of significant differences in soil humidity, pH and organic carbon between the sites. However, plant species and soil properties were the two factors explaining variation in AMF community composition, while grazing had no significant effect. Therefore, AMF communities in root of the semi-arid grassland plants responded largely to plant type rather than to grazing intensity.

Slope aspect of a mountainous grassland landscape shapes the structure of an encroaching shrub (Euryops floribundus N.E. Br): insights from communal grazing sites located at varying distances from rural homesteads

Mountainous grassland landscapes are severely threatened by the proliferation of shrub encroachment. So far, it remains unclear though how slope aspect coupled with land disturbances linked to the proximity of homesteads to communal grazing sites affects the distribution, density and structure of the encroaching shrubs in these grassland ecosystems. In this study, we investigated the role that slope aspect plays in determining the density and structure of an encroaching shrub species Euryops floribundus N.E. Br in three communal grazing sites located at varying distances from rural homesteads in a semi-arid mountainous grassland in the Eastern Cape Province of South Africa. Three sites were strategically chosen in Cala communal grazing lands in an encroached mountainous grassland landscape that depicted north and south-facing slope aspects. The selected sites were Tsengiwe; a site located in close proximity to homesteads at a distance of less than 100 m, Upper Mnxe situated at an intermediate distance ranging from 200 to 800 m away from homesteads and Manzimdaka, which was located furthest from homesteads at a distance greater than 1600 m. In each site and corresponding slope aspect, the density and structure of the shrub E. floribundus were evaluated on 36 randomly distributed plots, yielding a total of 108 plots across all sites. We found that shrub density was significantly higher (50%) on the north-facing slope compared to the south-facing slope in Tsengiwe, the site located near homesteads. Shrub height was significantly higher (53 and 17%) on the north-facing slope compared to the south-facing slope at Upper Mnxe and Manzimdaka, which were located at intermediate and furthest distances from the homesteads. Notably, shrub height was significantly lower (37%) in the north-facing slope compared to the south-facing slope in Tsengiwe. Following a similar pattern to shrub height, total stem number was significantly higher (20 and 85%) in the north-facing slope compared to the south-facing slope at Upper Mnxe and Tsengiwe, respectively. Shrub crown area was higher (33 and 11%) in the north-facing slope compared to the south-facing slope at Upper Mnxe and Manzimdaka, respectively. A strong positive relationship was established between the height of shrubs and their longest crown diameter, shortest crown diameter and shrub crown area across all sites, suggesting that the investigated shrub species E. floribundus employs its structural characteristics to survive, and thrive and this was more evident in the north-facing slope. The results highlight the importance of considering the proximity of homesteads into account in ecological studies, and puts emphasis on improved understanding of the vegetation patterns shaped by shrub encroachment in mountainous grasslands, which is crucial in the development of effective land management strategies.

Soil quality and vegetation cover characteristics as influenced by diverse grazing regimes and soil disturbance histories in a semi-arid rangeland (Iran)

This study investigates the soil functioning and regeneration processes in a semi-arid rangeland subject to an eleven-year conservation grazing (CG) program within the Gonbad paired watershed in Hamadan, Iran. Five distinct sites with varying rangeland vegetation cover were selected based on differences in grazing regimes and soil disturbance histories. These sites include: CG site with Astragalus-Artemisia vegetation (CG(A-A)); CG site with Astragalus-Bromus vegetation (CG(A-B)); CG site, easily accessible to grazing livestock, with Astragalus-Lactuca vegetation (CG(EA)); CG site with a history of past rainfed farming and Centaurea-Grasses vegetation (CG(PRF)); and free grazing (FG) site with Astragalus-Euphorbia vegetation. In addition, a long-term rainfed farming site (RF) was studied as the dominant land use. Rangeland management practices had a discernible impact on nearly all soil quality (SQ) indicators. However, due to their strong interdependence, only soil aggregate stability, carbohydrates, and phosphatase activity proved to be critical indicators representing soil functioning in the area. The general SQ index illustrated a decline in soil functioning at RF (58%), CG(PRF) (55%), FG (42%), and CG(EA) (22%) sites compared to sites classified as "good" (CG(A-A) and CG(A-B)). Total organic carbon and carbon stock were only recovered in well-restored sites, characterized by a predominance of shrubs and perennial grasses. Meanwhile, active carbon and carbohydrates revealed the positive effects of conservation grazing in moderately and poorly restored sites, characterized by a predominance of forbs and annual grasses. Our findings suggest that soil disturbance history and grazing accessibility are critical factors for successfully implementing conservation grazing management in the area.

Effects of SNP marker density and training population size on prediction accuracy in alfalfa (Medicago sativa L.) genomic selection.

Effects of individual single-nucleotide polymorphism (SNP) markers and the size of "training" and "test" populations affect prediction accuracy in genomic selection (GS). This study evaluated 11 subsets of 4932 SNPs using six genetic additive methods to understand marker density in GS prediction in alfalfa (Medicago sativa L.). In the GS methods, the effect of "training" to "test" population size was also evaluated. Fourteen alfalfa populations sampled from long-term grazing sites were genotyped using genotyping by sequencing for the identification of SNPs. These populations were also phenotyped for six agromorphological and three nutritive traits from 2018 to 2020. The accuracy of GS prediction improved across six GS methods when the ratio of "training" to "test" population size increased. However, the prediction accuracy of the six GS methods reduced to a range of -0.27 to 0.11 when random, uninformative SNPs were used. In this study, five Bayesian methods and ridge-regression best linear unbiased prediction (rrBLUP) method had similar GS accuracies for "training" sets, but rrBLUP tended to outperform Bayesian methods in independent "test" sets when SNP subsets with high mean-squared-estimated-marker effect were used. These findings can enhance the application of GS in alfalfa genetic improvement.

A field assessment to validate the assumptions of the Tea Bag Index (TBI) as a measure of soil health

This study evaluated key assumptions underlying the Tea Bag Index (TBI) as a soil health assessment tool through a time series conducted under field conditions. The TBI assesses soil health by measuring the decomposition rates of standardized green and red tea over a 90-day incubation period. Our research was conducted on a degraded 33.6-ha agricultural site in North Saanich, British Columbia, where we compared two plots: a reference site and a grazed site, each representing distinct land use conditions.The first assumption evaluated was that the TBI metrics of S (stabilization rate) and k (decomposition rate) follow exponential decay models. While S adhered to this assumption, k did not, suggesting additional as yet undetermined influences on decomposition rates. We introduced new biological metrics, Bg and Br, which followed polynomial models of decay, and may reflect the decomposition of different materials over time by different soil organisms.The second assumption tested was that a 90-day incubation period adequately captures the timeframe required for labile litter consumption. Our findings indicated that decomposition variance plateaued after 105 days, and that an increase in incubation time by 35 days increased the precision of mathematical decomposition models by a mean value of 18.1 %.The final assumption tested was that litter decomposition rate varies with land use. Our findings affirm that land use does affect litter decomposition rate, although the specific sources of that variance remain unclear.TBI accuracy can be improved by extending the litter incubation time to at least 105 days. Incorporating biological metrics (Bg and Br) increases the TBI's precision. Our results reaffirm the TBI's sensitivity to land use differences, highlighting its potential as a cost-effective tool for assessing soil health under varying conditions.

Soil and plant attributes under grazing exclusion in semi-steppic semi-arid rangelands, Iran

The aim of this study was to investigate the effect of exclusion (20 years) on the attributes of soil and vegetation in northwest of Iran. Three sites in grazed and three sites in exclusion areas were selected. At each site, three 100 m transects were established for sampling purposes. Soil attributes, including electrical conductivity, pH, calcium carbonate, organic carbon, nitrogen, phosphorus, potassium, clay, silt, calcium, magnesium, and bicarbonate were measured in the lab. Additionally, the primary and secondary attributes of vegetation including density, canopy cover, aboveground net primary production (ANPP) of plant functional types (PFTs), diversity, richness and evenness indices were recorded. The findings of our study indicate that the exclusion site exhibited significantly higher levels of soil organic carbon (1.91%), total nitrogen (0.95%), available phosphorus (1.75 ppm), and soluble potassium (163.52 ppm) compared to the grazed site. However, no significant differences were observed in other soil characteristics between the two sites. Density, canopy cover percentage, ANPP of PFTs (p < .01), diversity (1.92), and richness index (9.64), were higher in the exclusion area (p < .05), while, evenness showed no significant difference. The total species density and canopy cover within the exclusion area were also found to be higher than in grazed areas. Results suggest that exclusion in semi-arid semi-steppes plays an important role in rangeland management.

Effect of moderate livestock grazing on soil and vegetation characteristics in zokor mounds of different ages

Mounds formed by plateau zokors (Eospalax baileyi) in alpine meadows are easily disturbed by livestock. We aimed to reveal the effect of moderate livestock grazing (from October 15 to March 15 of the following year) on plant and soil characteristics of zokor mounds. This study explored the effect of zokor mounds of different ages (2015–2018) on soil nutrient content, soil enzymatic activity, plant diversity, and aboveground biomass (AGB) at grazing and non-grazing sites. Compared with the non-grazing sites, soil organic carbon (SOC), total soil phosphorus, and ratio of SOC to total nitrogen were 16.6%–98.7% higher and soil urease activity was 8.4% and 9.6% higher in 1- and 3-year-old mounds, respectively, at the grazing sites. Grazing significantly increased the plant Pielou index, richness, and Shannon–Wiener diversity index of 4-year-old mounds by 20.7%–52.4%. Partial least squares path modeling showed that plant species diversity was the main factor affecting the plant AGB of mounds at the grazing sites, whereas soil enzyme activity was the primary factor at the non-grazing sites. We propose that moderate grazing increases soil nutrient content and the plant diversity in zokor mounds in alpine meadows, which should be considered in future grassland restoration.

Determining fire frequency and its relationship with rangeland aboveground grass biomass using MODIS and Landsat imagery

ABSTRACT High frequency burned area (BA) images provide an opportunity to monitor rangeland fire frequency (FF). This study related grass aboveground biomass (AGB) to FF in a 4800 ha biodiversity conservation savannah-grassland rangeland. Archived (2000–2021), 500 m resolution MODIS burned area monthly images were used. Following Boolean coding (fire event pixel = 1, no-fire pixel = 0), addition GIS overlay analysis yielded total fires per pixel location. Fire detection accuracy was assessed using 2018–2021 management fire event records. Sample grass AGB data were obtained at the end of the 2020 and 2021 growing seasons from widely dispersed sampling sites with wide grass cover uniformity, where a 1 m quadrat was tossed randomly in a 20 m × 20 m plot up to three times. The quadrat-enclosed grass was harvested to soil level, air-dried, and weighed to generate site average AGB values, which were correlated with vegetation index (VI) values from sampling near-concurrent surface reflectance (L2SP) Landsat-8 OLI images. Four biomass-sensitive VIs utilising Landsat sensor spectral ranges were tested. The Enhanced Vegetation Index (EVI) yielded the strongest relationship (r = 0.410, p < 0.01). A linear model predicting grass AGB from EVI values was developed using 58% of sample data for training (R 2 = 0.3062, p < 0.01) and 42% for validation (R 2 = 0.5225, p < 0.001). Using the model, sampling site historical grass AGB values were predicted on same season, L2SP Landsat (TM, ETM+, OLI) images from 2000, 2002, 2006, 2009, 2013 and 2016, whose dates were selected by comparing rainfall. The MODIS images detected 73% of fires larger than 25 ha (one pixel). Most sites experienced long-term AGB gains, at faster rates in high FF (4–5 fires), low grazing sites. Most fires occurred as ecologically undesired late burns, indicating the utility of archived high-frequency BA images for rangeland management.

Effects of grazing on soil water recharge of rehabilitated grassland under natural rainfall on the Loess Pla-teau, Northwest China.

Rainfall is critical to the regulation of slope runoff and soil water recharge. Grazing affects land cover and soil structure, with consequence on slope runoff generation and soil water recharge. Little attention has been paid to the effects of rainfall on soil water recharge caused by grazing. In this study, we examined land covers and soil water contents under different grazing intensities (G1-G5: 2.2, 3.0, 4.2, 6.7, 16.7 sheep·hm-2) and no grazing sites (NG), aiming to analyze soil water recharge under natural rainfall conditions after grazing. The results showed that grazing exerted significant effects on vegetation and biocrust coverage. The vegetation coverage was decreased by 8.3%-16.4% under G1-G5 grazing, while the biocrust coverage was increased by 106.9% under G2 grazing compared to NG. The soil surface roughness under G1-G5 grazing was increased by 53.1%-152.5%, and the thickness of biocrust was decreased by 24.1% under G5. Soil wetting front velocity decreased with increasing rainfall intensity, and that of 0-5 cm layer under the G2 grazing intensity decreased by 60.0% to 83.3% under rainfall between 18.0 mm and 70.3 mm compared to NG. The effect of grazing on soil wetting front velocity was significantly related to biocrust coverage and soil bulk density of 0-5 cm soil layer. Generally, grazing did not affect soil water recharge rates of the slope grassland on the Loess Plateau. G2 grazing may prolong the migration time of soil water in the surface layer by increasing the coverage of cyanobacteria biocrusts, which may be beneficial to the restoration of soil microenvironment. Our results provided scientific basis for water management in the enclosure grassland of the Loess Plateau in the "post-conversion era".

Structure and Phenology of Herbaceous Stratum in the Sahelian Rangelands of Senegal

This study describes the structure and phenology of Sahelian rangelands during the rainy season. It was undertaken on a grazed plot and a fenced plot. Measurements were taken every 10 days over two rainy seasons between July and October 2018 and between August and October 2019. The measurements included the phenological stage, the vegetative and flowering height, the coverage, and the phytomass. The results showed that phytomass did not systematically differ between grazed and fenced plots. Flowering started as early as mid-July, but most of the plants flowered in early October. Flowering and fruiting occurred earlier (based on the number of days after the first rain) in the late rainy season (2019) than in the early one (2018). These stages reached their peak in October; senescence began in October. Vegetative height, reproductive height, and coverage were similar between the two years. Height peaks were similar, but they were reached earlier (based on the number of days after the first rain) in the late rainy season than in the early one. Coverage peaks were similar (59.8% in the early rainy season vs. 65.8% in the late one). Vegetative height (around 30 cm), reproductive height (around 36 cm), and coverage (around 60%) reached their maximum in October, but reproductive height was greater than vegetative height. These parameters were lower at the grazed site compared to the fenced site, and flowering started earlier at the grazed site. The pasture had a negative impact on coverage, height, and early flowering. Structure and phenology were more sensitive than to changes in rainfall between years. Phenology results will help determine the best time to harvest the phytomass (phytomass stock), as the nutritional quality of the forage is known to decrease after fruiting.

Genetic diversity and local adaption of alfalfa populations (Medicago sativa L.) under long-term grazing

Genomic information on alfalfa adaptation to long-term grazing is useful for alfalfa genetic improvement. In this study, 14 alfalfa populations were collected from long-term grazing sites (> 25 years) across four soil zones in western Canada. Alfalfa cultivars released between 1926 and 1980 were used to compare degree of genetic variation of the 14 populations. Six agro-morphological and three nutritive value traits were evaluated from 2018 to 2020. The genotyping-by-sequencing (GBS) data of the alfalfa populations and environmental data were used for genotype-environment association (GEA). Both STRUCTURE and UPGMA based on 19,853 SNPs showed that the 14 alfalfa populations from long-term grazing sites had varying levels of parentages from alfalfa sub-species Medicago sativa and M. falcata. The linear regression of STRUCTURE membership probability on phenotypic data indicated genetic variations of forage dry matter yield, spring vigor and plant height were low, but genetic variations of regrowth, fall plant height, days to flower and crude protein were still high for the 14 alfalfa populations from long-term grazing sites. The GEA identified 31 SNPs associated with 13 candidate genes that were mainly associated with six environmental factors of. Candidate genes underlying environmental factors were associated with a variety of proteins, which were involved in plant responses to abiotic stresses, i.e., drought, cold and salinity-alkali stresses.

A Vision-Based Cattle Recognition System Using TensorFlow for Livestock Water Intake Monitoring

This letter presents a new method for identifying individual cattle for the purpose of tracking and efficiently measuring their daily water intake using a vision-based machine learning system. In addition to the current solution of using radio frequency identification (RFID), the proposed system uses TensorFlow Object Detection to detect labels on the RFID tag. The proposed system can be integrated into the current water intake monitoring system and alleviates the errors introduced by the unreliable RFID readers. The system allows users to train an object recognition model that can recognize and differentiate the labels on the ear tags of individual farm animals, so the drinking events can be recorded by the water intake monitoring system. The models are trained using custom datasets of manually annotated tag images with pretrained model architectures from TensorFlow 2 Model Zoo. The system is tested using images from event-triggered weather-proof cameras deployed in the grazing site. Experimental results of the system showed an accuracy of around 90%. In comparison to other present methods, this newly proposed system provides scalability and flexibility, making it an attractive vision-based solution for machine learning systems in agriculture.

Displacement Effects of Conservation Grazing on Red Deer (Cervus elaphus) Spatial Behaviour

Conservation grazing uses semi-feral or domesticated herbivores to limit encroachment in open areas and to promote biodiversity. However, we are still unaware of its effects on wild herbivores. This study investigates the influence of herded sheep and goats on red deer (Cervus elaphus) spatial behavior by testing three a-priori hypotheses: (i) red deer are expected to avoid areas used by livestock, as well as adjacent areas, when livestock are present, albeit (ii) red deer increase the use of these areas when sheep and goats are temporarily absent and (iii) there is a time-lagged disruption in red deer spatial behavior when conservation grazing practice ends. Using GPS-telemetry data on red deer from a German heathland area, we modelled their use of areas grazed by sheep and goats, using mixed-effect logistic regression. Additionally, we developed seasonal resource selection functions (use-availability design) to depict habitat selection by red deer before, during, and after conservation grazing. Red deer used areas less during conservation grazing throughout all times of the day and there was no compensatory use during nighttime. This effect mostly persisted within 21 days after conservation grazing. Effects on habitat selection of red deer were detectable up to 3000 meters away from the conservation grazing sites, with no signs of either habituation or adaption. For the first time, we demonstrate that conservation grazing can affect the spatio-temporal behavior of wild herbivores. Our findings are relevant for optimizing landscape and wildlife management when conservation grazing is used in areas where wild herbivores are present.