Background: The time-series data of the Normalized Difference Vegetation Index (NDVI) is a crucial indicator for global and regional vegetation monitoring. However, the current assessment of global and regional long-term vegetation changes is subject to large uncertainties due to the lack of spatiotemporally continuous time-series data sets.

Methods: In this study, a long time-series monthly NDVI data set with a spatial resolution of 250m from 1982 to 2020 was developed by combining Moderate Resolution Imaging Spectroradiometer (MODIS) and AVHRR (Advanced Very High-Resolution Radiometer) time-series NDVI products using the Random Forest (RF) downscaling model.

Results: Compared to the MODIS NDVI product, the fused product shows RMSE and mean absolute error ranging from 0 to 0.075 and from 0 to 0.05, respectively, with R² values mostly above 0.7.

Conclusions: The long time-series NDVI products generated in this study are reliable in terms of accuracy and have great potential for long-term dynamic monitoring of terrestrial ecosystems on the Qinghai–Tibet Plateau.

Background: Perennial ryegrass (Lolium perenne) in New Zealand pastures is typically infected with the mutualist Epichloë fungal endophyte. This endophyte assists the plant in resisting biotic and abiotic stresses, but the standard strain of endophyte is toxic to livestock. Elite ryegrasses with selected endophytes have been developed to provide protective properties to the grass plant and lessen or eliminate the negative impacts on livestock.

Methods: Using immunology and molecular techniques, the presence of endophyte infection and endophyte strain in ryegrass tillers was determined for 24 dairy pastures sampled for up to 7 years in regions of the North and South Islands.

Results: In general, infection levels were high and showed small increases over time. Some pastures failed to reach 70% infection. The sown, selected endophytes were the dominant endophyte strains present and these were stable over time. Standard endophyte was the primary nonsown endophyte, and while generally low and so of little importance, it increased over time and for some pastures, this would have been detrimental to livestock. Pasture establishment technique influenced the level of contamination.

Conclusions: Results reinforce the importance of following best practice procedures in the seed industry and on-farm. Researchers should monitor trials for contaminating nonsown standard endophyte.

Bermudagrass (Cynodon dactylon (L.) Pers.) is one of the primary perennial forages in the southeastern USA. Newer hybrid cultivars have superior production and nutritive value compared to common ecotypes. However, there are many challenges facing bermudagrass production in the region. First, the bermudagrass stem maggot (BSM; Atherigona reversura Villeneuve) has severely damaged bermudagrass throughout the region. Strategically timed pyrethroid applications significantly reduce adult BSM populations, but efforts are needed to develop integrated pest management plans. Second, an increasing number of producers are noting challenges with green-up following winter dormancy. This may be attributed to disease, unbalanced soil fertility, and weed pressure. Perhaps one of the most limiting factors for continued production is the deficit of sprigs and trained personnel to sprig hybrid bermudagrasses. This research is critically important as the need for cold-tolerant bermudagrass is increasing as tall fescue (Lolium arundinaceum (Schreb.) S. J. Darbyshire) is declining due to changes in temperature and precipitation throughout the northern parts of the region. Plant breeders are investigating hybrid bermudagrass at latitudes >35° with respect to freeze or cold tolerance. Despite the many challenges facing hybrid bermudagrass in the southeastern USA, researchers are working to ensure its persistence, productivity, and availability for the future.

Background: Tall wheatgrass is a perennial salt-tolerant bunchgrass, which is a promising candidate for establishing a “Coastal Grass Belt” in China, particularly in the coastal saline–alkaline soils surrounding the Bohai Sea.

Methods: Seven harvesting treatments were performed to explore the optimal harvesting time and frequency for tall wheatgrass in coastal area. The dry matter yield (DMY) and forage nutritional values were investigated for each cut. The correlation between harvesting time and frequency thereof among the investigated traits was also determined.

Results: The results showed that the two-cut on June 18 and October 29 produced the highest DMY. Another two-cut on May 26 and October 29 produced a relatively high crude protein (CP) yield. The DMY, contents of neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude cellulose (CC) as well as CP yield were positively correlated to plant height, while the CP content and the relative feed value (RFV) were negatively correlated to plant height. The accumulating growing degree days, accumulated precipitation, and sunshine duration were positively correlated with plant height, DMY, contents of NDF, ADF, and CC as well as CP yield, but negatively correlated with CP content and RFV for the first cut.

Conclusions: The two-cut treatment at the end of May and October may be suitable for tall wheatgrass in the “Coastal Grass Belt” targeted area.

Background: Genotype × environment interaction (GEI) slows genetic gains and complicates selection decisions in plant breeding programs. Forage breeding program seed sales often encompass large geographic regions to which the cultivars may not be adapted. An understanding of the extent of GEI in perennial, cool-season forage grasses will facilitate improved selection decisions and end-use in areas with harsh winters.

Methods: We evaluated the dry matter yield of nine meadow brome (Bromus biebersteinii Roemer & J. A. Schultes), nine orchardgrass (Dactylis glomerata L.), seven tall fescue (Lolium arundinaceum (Schreb.) Darbysh.), and 10 timothy (Phleum pratense L.) cultivars or breeding populations at seven high latitude and/or elevation locations in Canada and the United States from 2019 to 2021.

Results: For each of the species, we found significant differences among the genotypes for dry matter yield across environments and found significant levels of GEI. Using site regression analysis and GGE biplot visualizations, we then characterized the extent of the interactions in each species. Except for tall fescue, there was little evidence for the broad adaptation of genotypes across locations.

Conclusions: This research adds further evidence to the limitations of perennial, forage breeding programs to develop widely adapted cultivars and the need to maintain regional breeding efforts.

Background: Gut microbiota is pivotal in regulating hosts’ biological processes and maintaining homeostasis, but knowledge about its role in wild herbivores in extreme environments remains limited.

Methods: Gut bacteria and fungi were sequenced in ruminant (Chiru and Yak) and nonruminant (Kiang) herbivores on the Qinghai–Tibet Plateau, and their community structure, co-occurrence networks, functions, and assembly mechanisms were investigated using multivariate ecological and statistical methods.

Results: Kiang had lower gut microbial diversity than Chiru and Yak. Bacterial host-specific exclusivity was greater than that of fungi. In addition to the evidence of glycan biosynthesis and carbohydrate metabolism, Chiru had a high Firmicutes/Bacteroidetes ratio and low animal pathogen abundance, suggesting better adaptation to the plateau’s harsh environment. Additionally, members of gut microbiota tended to co-occur rather than co-exclude in all herbivores. Different network complexity and stability patterns were observed between bacterial and fungal communities. Furthermore, gut bacterial assembly was primarily controlled by stochastic dispersal limitation and drift, whereas fungal assembly was primarily controlled by deterministic homogeneous selection except in Chiru.

Conclusions: On the Qinghai–Tibet Plateau, Chiru and Yak exhibit more diverse gut microbiota and more diverse metabolic functions than Kiang, and gut bacteria are more divergent than gut fungi in these herbivores.

Background: Soil structure is a key indicator of the functioning of soil processes in grasslands, which is influenced by site conditions and management.

Methods: In this study, we investigated soil structure and its relationship with root growth in 31 Leptosols under different grassland management intensities using X-ray microcomputed tomography. A close relationship between land use intensity, soil structure, and root growth was observed.

Results: Our results show that land use type affects root development and soil structure. Pastures had more developed roots and more structured soils than meadows and mown pastures. However, all pastures were unfertilized, while meadows and mown pastures had both fertilized and unfertilized plots. Although no significant differences were found in the unfertilized plots, sample size was limited. In particular, fertilization negatively affected root growth and soil structure, resulting in significant differences between fertilized and unfertilized grasslands. Mowing frequency also had an effect on soil physics, but to a much lesser extent than fertilization.

Conclusions: Increased land use intensity, characterized by increased fertilization and more frequent mowing, reduces root growth and adversely affects soil structure. Therefore, X-ray microcomputed tomography is a suitable method to investigate the relationship between soil structure and roots in the soil.

Alfalfa use (Medicago sativa L.; “lucerne”) in warm, humid regions of the world represents a potential area of expansion for the alfalfa industry. The objective of this review paper is to demonstrate how alfalfa forage breeding and systems research efforts have identified opportunities for increasing alfalfa contributions in these regions, along with potential pathways for seed industry and farming operations to increase adoption. Our review draws primarily on reports from the Southeast United States and Argentina. Significant technological advancements in plant screening and selection have identified alfalfa plant populations that are more adapted to the growing conditions experienced in these regions, which are often characterized by mild temperature, long growing seasons, and multiple other abiotic and biotic stressors. Management systems research conducted in the United States and Argentina has demonstrated the use of alfalfa for conserved forage, grazing, or dual-purpose use in monoculture or mixtures with warm-season grasses such as bermudagrass (Cynodon spp.). These trials report increased forage production, nutritive value, and ecosystem services of alfalfa–grass mixtures when compared with traditionally N-fertilized warmseason grass-based systems. Grazing-based alfalfa systems in Argentina have demonstrated methods for utilizing alfalfa as part of beef, dairy, and finishing systems. Some approaches for expanding alfalfa production in the region include targeted marketing efforts for adapted varieties and demonstrating alfalfa applications within existing farming frameworks. This includes educational programming efforts and on-farm demonstrations to promote alfalfa use as a component of the livestock diets, integration into grass-based systems, crop rotations, and wildlife use. Continued emphasis on a systems approach to alfalfa inclusion represents an opportunity for improved forage and livestock production in warm, humid regions of the world.

Background: The ability to finish livestock on pasture over the summer–autumn period could improve the profitability of red meat enterprises in drought-prone temperate regions. In south-eastern Australia, traditional perennial options are limited by poor warm-season performance (phalaris, Phalaris aquatica L.) and widespread environmental constraints (lucerne, Medicago sativa L.). We aimed to identify perennial species suitable for summer–autumn finishing.

Methods: We tested pure swards of summer-active perennial grasses and herbs (20 cultivars across 14 species) in replicated small-plot experiments at two sites on the Southern Tablelands of New South Wales, Australia. We assessed early persistence, productivity and warm-season nutritive characteristics over 2–3 years.

Results: Lucerne and chicory (Cichorium intybus L.) persisted well through drought and produced herbage of high quantity and quality through summer–autumn. Digit grass (Digitaria eriantha Steud.) was highly persistent and productive but nutritive values were generally poor. Cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), perennial ryegrass (Lolium perenne L.), prairie grass (Bromus willdenowii Kunth.) and plantain (Plantago lanceolata L.) were productive but less persistent through drought, while nutritive values were sometimes inadequate.

Conclusions: Chicory is a good alternative to lucerne, given its excellent summer–autumn performance, ability to survive droughts and superior acid soil tolerance. If appropriate management resolves issues with persistence and nutritive value, several of the other species could also be used to close the warm-season feed gap in drought-prone temperate environments.