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Global warming, elevated atmospheric CO2 concentrations and increased likeliness of extreme drought and wildfires in many regions will likely favour C4 grass species. To support future management actions, we explored the effect of the encroachment of an invasive perennial C4 grass, Sporobolus cryptandrus on the composition of soil seed banks in dry sand grasslands in Central Europe. In five mass‐locality sites of the species we assessed the composition and vertical segmentation of the soil seed bank in 12 1‐m2 plots along an increasing cover of the invasive species. We found that the seed bank diversity and density decreased with increasing sampling depth; the decrease in density was affected by the increasing S. cryptandrus cover. Neither the diversity nor the seed bank density of other species were affected by increasing S. cryptandrus cover but both were affected by the sampling site. Most of the studied seed bank characteristics were affected by the sampling depth, but none of them were affected by the increasing cover of S. cryptandrus. Increasing cover of S. cryptandrus in the vegetation was associated with an increasing proportion of S. cryptandrus seeds in the seed bank, and we found a low‐density soil seed bank of the species even in plots with no S. cryptandrus cover. Our finding that S. cryptandrus forms a massive soil seed bank, together with the predicted decrease in the precipitation of the summer months and increase in the frequency of droughts in the region, projects further rapid spread of the species. [ABSTRACT FROM AUTHOR]

The specialisation-disturbance hypothesis (SDH) predicts that specialist and generalist taxa respond differently to disturbance, with generalists more tolerant of disturbance, while habitat stability (i.e. no/limited disturbance) should favour specialist species. If the SDH holds true, this would have implications for the design and implementation of biological control programmes, in terms of performing native-range surveys in search of candidate agents and subsequent development of management programmes for their release in the weeds invaded range. We assessed the effect of anthropogenic disturbance (mowing/slashing and fire) on the endophagous insect communities associated with two African grasses, Sporobolus pyramidalis and Sporobolus natalensis (Poaceae), that are targets for biological control in Australia. Comparisons, of insect community structure and presence/abundance of each species between disturbed and undisturbed sites, were made at 19 sites in South Africa. Disturbance caused a shift in insect species composition and abundance, whereby specialist insects were less frequently encountered and less abundant at disturbed versus undisturbed sites. If the potential agents for Sporobolus spp. are released in Australia they may be negatively affected by disturbance and may therefore be incompatible with certain integrated management strategies, such as mowing and prescribed burning. Moreover, our results suggest that field sites with limited disturbance should be prioritised during native-range surveys to maximise the chances of locating specialist natural enemies. The effect disturbance has on insect community composition may be particularly relevant for the biological control of invasive grasses, due to the intensity of disturbance of grasslands worldwide. [ABSTRACT FROM AUTHOR]

Understanding how the salt marsh vegetation will evolve under future climate conditions is essential for predicting the role of marsh ecosystem services in a warmer climate with higher CO2-concentrations. In a mesocosm experiment in the northern Wadden Sea, the impact of increased temperature (+ 3 °C) and CO2 (800 ppm) on salt marsh vegetation was investigated, assessing biomass production in the pioneer zone and low marsh. The pioneer zone, which was dominated by Spartina anglica and exposed to natural tidal inundations, demonstrated a differentiated response between belowground and aboveground biomass. Aboveground biomass increased in response to enhanced CO2 availability, and belowground biomass increased in response to raised temperatures. Other plant species accounted for less than 18% of the aboveground biomass, and their biomass was suppressed under high CO2 availability. Increased biomass by Spartina anglica may improve resilience toward sea level rise. Hence, the pioneer zone is expected to maintain its coastal protection and blue carbon storage capacity under future climate conditions. The low marsh, which was dominated by Elymus athericus, was exposed to higher than usual tidal inundations and resembled a scenario with increased sea level. The low marsh showed no response in biomass to increased CO2 or temperature, which may be due to the increased flooding. The positive response of Spartina anglica (C4 plant) and the lack of response in Elymus athericus (C3 plant) counter the notion that C3 plants are more productive under future climate conditions and demonstrate that C4 plants can also thrive in future salt marshes. [ABSTRACT FROM AUTHOR]

Whole genome duplications (WGDs) lead to polyploid specimens and are regarded as major drivers for speciation and diversification in plants. One prevalent problem when studying WGDs is that effects of polyploidization in ancient polyploids cannot be disentangled from the consequences of selective evolutionary forces. Cytotypic differences in distribution, phenotypic appearance and in response to surface elevation (determined by HOF-modeling) were identified in a relatively young taxa-group of a hexaploid F1-hybrid (Spartina× townsendii H. Groves & J. Groves, Poaceae) and its dodecaploid descendent (Spartina anglica C.E. Hubbard, Poaceae) using vegetation assessments (1029 plots; 1 × 1 m2) from the European Wadden Sea mainland salt marshes, including elevational and mean high tidal (MHT) data. While the F1-hybrid was mainly present in the eastern part of the Wadden Sea, its dodecaploid descendent occurred in the entire Wadden Sea area. The Spartina cytotypes differed in phenotypes (median of Spartina cover: hexaploid = 25% vs. dodecaploid = 12%) and in elevational niche-optimum (hexaploid = − 49.5 cm MHT vs. dodecaploid = 8.0 cm MHT). High ploidy levels correlated with establishment success in Spartina along geographic gradients but did not seem to increase the capacity to cope with abiotic severity downwards the elevational gradient in salt marshes. [ABSTRACT FROM AUTHOR]

Salt marshes are ecosystems of significant ecological importance for coastal stability and fundamental roles in marine ecosystems. Salt marshes are declining due to anthropogenic and natural causes including sea level rise. Coastal restoration efforts have increased worldwide, but many fail in long-term coastal stability. We used a naturally occurring arbuscular mycorrhizal fungus (AMF) to test whether survival and early growth of the salt marsh grass Sporobolus pumilus (formerly Spartina patens) improved under simulated salt marsh conditions. Using a tidal mesocosm bench, we grew inoculated plants with varying AMF treatments under simulated tidal regimes to determine if AMF could aid in establishment of healthy Sporobolus communities. Rhizome-derived S. pumilus had greater survival and grew faster than seed-derived plants. Plants inoculated with propagated AMF consistently outperformed both sterile and native sediment controls in terms of plant survival and growth. Use of rhizome-derived Sporobolus inoculated with propagated Funneliformis geosporum showed the most promise in producing successful plant populations for salt marsh restoration. This may be due to plant life stage and improved plant nutrient status, allowing rhizome-derived plants to grow more quickly than seed-derived plants. Using these plants in future large-scale restoration may increase re-establishment of salt marsh ecosystems.

Sporobolus vaginiflorus is native to North America but it has been introduced in some areas beyond its natural range and has been recently recorded in Bosnia and Herzegovina. In the period of 2018-2019, it was recorded in 43 new localities in South Herzegovina and Central Bosnia. On the basis of the number of populations and the number of individuals within populations, the authors assume that this species is now invasive in Bosnia and Herzegovina. [ABSTRACT FROM AUTHOR]

Biological control (biocontrol) of invasive alien plants is a widely utilised weed management tool. Prospective biocontrol agents are typically assessed through host specificity testing and pre‐release efficacy studies performed in quarantine. However, rearing of the potential biocontrol agents and/or test plants is often difficult or impossible under quarantine conditions. Moreover, practitioners may attain laboratory artefacts in quarantine, which may result in the potential agent being needlessly rejected. Field‐based studies in the weed's indigenous distribution could overcome these issues.Sporobolus pyramidalis and Sporobolus natalensis (giant rat's tail grass; Poaceae) are indigenous in Africa but have become problematic invasive alien plants in Australia. A previous biocontrol program was terminated because the candidate agent could not be reared and tested in quarantine. We performed field‐based host specificity and efficacy studies for prospective biocontrol agents in South Africa (indigenous distribution). Forty‐seven non‐target grass species were sampled during host specificity assessments. Candidate agent efficacy was estimated based on damage to the target weeds, for each host specific candidate individually and in combination with other host‐specific candidates.Three species of endophagous wasps were deemed host specific. Efficacy assessments identified an undescribed stem‐boring wasp (Tetramesa sp.) species as the most damaging candidate. A second Tetramesa species was much less damaging alone but had a cumulative impact on the plant in combination with the more damaging Tetramesa species. Both Tetramesa species are recommended for importation into quarantine in Australia for confirmatory host specificity testing with a significantly reduced test plant list.Synthesis and applications. Similar field‐based assessments in the indigenous distribution of weeds targeted for biocontrol could be included in the future programs. Where rearing of potential agents and/or test plants is difficult or impossible under quarantine conditions, our field‐based method provides an alternative. Where quarantine‐based testing is feasible, this method ensures that only candidates that have passed an ecologically realistic host‐specificity and potential efficacy screening are imported into quarantine. This may reduce the number of agents that are imported and the length of time each agent is kept in quarantine. This is advantageous because quarantine space is highly valuable and is usually a limiting factor in pre‐release assessments of biocontrol agents. [ABSTRACT FROM AUTHOR]

The cordgrass Spartina anglica C.E. Hubbard (Poaceae) is an invasive transformer in many salt marsh ecosystems worldwide. Relatively little is known about the capacity of Spartina to accelerate salt marsh succession and to protect salt marshes against sea level rise. We analyzed long-term changes in vegetation and elevation in mainland salt marshes of the European Wadden Sea in Schleswig-Holstein, Germany, to estimate the impact of non-native Spartina on the geomorphological resistance of salt marshes to sea level rise and on changes in species diversity. From 1989 to 2019, the Spartina-zone shifted and expanded upwards to elevations of the high marsh zone and Spartina increased in frequency in several salt marsh vegetation communities. At sites where Spartina dominated the vegetation already three decades ago, elevation and species diversity increased with a higher rate compared to sites lacking Spartina. The median change rates reached for elevation MHT +8.6 versus +1.5 mm per year, for species richness +3 versus ± 0 species per three decades, and for evenness +0.04 versus −0.08 per three decades, regarding plots with versus without former Spartina dominance, respectively. Invasion of salt marshes by Spartina and its continued, long-term presence were associated with increased elevation and species diversity in the face of sea level rise. [ABSTRACT FROM AUTHOR]

Soil salinization and alkalinization frequently co-occur in nature, but very few studies focus on the interactive effects of mixed salt and alkali stresses on plants. Sporobolus marginatus Hochst. ex A. Rich. (perennial halophytic grass) collected from extreme saline sodic Kachchh plains, Bhuj, Gujarat was analyzed to evaluate the stress specific responses in osmoprotectants, antioxidants, ionic relations and protein profiling under saline, sodic and mixed saline-sodic soils. Osmotic adjustments in terms of total soluble sugars (TSS), glycine betaine, proline content and protein concentration exhibited differential responses to variable stress conditions. Proline content increased 4.8 folds at pH2 10.0, 5.2 folds at ECe 35 dSm-1 and 5 folds at pH2 9.0 + ECe 20 dSm-1. The greater accumulation of proline in Sporobolus, may presumably be one of the factor for tolerance to higher salt. At the same time, superoxide dismutase (SOD) activity in leaves increased with increasing sodicity i.e. 30.73 and 33.55 units g-1 FW at pH 9.5 and pH 10.0, respectively. Gradual increase in peroxidase enzyme (POX) activity was observed under all the stresses. Under control condition, POX activity was 21.67 units g-1 FW in Sporobolus, which increased to 26.56 units g-1 FW at pH 10.0, 27.89 units g-1 FW at ECe 35 dSm-1 and 27.44 units g-1 FW at pH 9.0 + ECe 20 dSm-1. The basal activity of APX increased with increasing stress conditions and was maximum (43.91 units g-1 FW) at pH 10.0. On the other hand, 2 times higher glutathione reductase (GR) activity was obtained under sodic stress of pH 9.5 and pH 10.0. SDS-PAGE revealed that five new polypeptide bands of MW 58.5, 53.7, 39.7, 31.8 and 28.3 kDa were expressed at higher saline level while one polypeptide band of 39.7 kDa disappeared at higher salinity level of 35 dSm-1 which may be due to its degradation at higher salt concentration. Synthesis of common polypeptides of MW 98.1, 69.3, 35.45, 24.89 and 23.3 kDa under all the stress conditions need special mention. Furthermore, the enhanced expression of these proteins, which also existed in the control plants, were specifically increased under stress condition which revealed that these proteins were up-regulated in specific regions of Sporobolus adapted to salt stress. Therefore, further exploration is needed to test the contribution of salt stress related proteins/genes or regulatory factors from the salt tolerant grasses (STGs) for possible utilization in cereal crop improvement. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to survey the abundance and genetic diversity of legume-nodulating rhizobia (LNR) in the rhizosphere of a salt-tolerant grass, Sporobolus robustus Kunth, in the dry and rainy seasons along a salinity gradient, and to test their effectiveness on Prosopis juliflora (SW.) DC and Vachellia seyal (Del.) P.J.H. Hurter seedlings. The results showed a significant decrease in LNR population density and diversity in response to salinity, particularly during the dry season. A phylogenetic analysis of the 16S-23S rRNA ITS region clustered the 232 rhizobium isolates into three genera and 12 distinct representative genotypes: Mesorhizobium (8 genotypes), Ensifer (2 genotypes) and Rhizobium (2 genotypes). Of these genotypes, 2 were only found in the dry season, 4 exclusively in the rainy season and 6 were found in both seasons. Isolates of the Mesorhizobium and Ensifer genera were more abundant than those of Rhizobium, with 55%, 44% and 1% of the total strains, respectively. The abundance of the Mesorhizobium isolates appeared to increase in the dry season, suggesting that they were more adapted to environmental aridity than Ensifer genospecies. Conversely, Ensifer genospecies were more tolerant of high salinity levels than the other genospecies. However, Ensifer genospeciesproved to be the most efficient strains on P. juliflora and V. seyal seedlings. We concluded that S. robustus hosts efficient rhizobium strains in its rhizosphere, suggesting its ability to act as a nurse plant to facilitate seedling recruitment of P. juliflora and V. seyal in saline soils. [ABSTRACT FROM AUTHOR]

Highlights • Plant performance on identical green roofs differed in cities 1000 s of km apart. • Climate altered plant survival, growth and phenology. • Canopy density higher in three species polyculture compared with monocultures. Abstract Green rooftops are installed in many climates worldwide to support urban ecosystem services. Across North America, green roofs often make use of the same limited set of plant species, but the effects of regional climates on the survival and growth of a core set of plant species has seldom been investigated. To identify the impact of climate on green roof plant performance, we installed an identical green roof system in three Canadian cities that experience different climate conditions: Calgary, Alberta; London, Ontario; and Halifax, Nova Scotia. The green roofs were monitored across three growing seasons for plant survival, plant height, and canopy density of three species grown in monoculture: Aquilegia canadensis , Sporobolus heterolepis , and Sedum spurium , and a mixture planting with all three species. Green roof vegetation canopy density, plant height and growth rates differed by city, plant species, substrate depth and planting type (monoculture or mixture treatment). Between sites, plant species exhibited different growth phenologies. Mixture treatments performed slightly better than monoculture plantings at each site in canopy density measures but were not significantly greater in plant height measures. The growth rate between years two and three was greatest for the mixture treatment, indicating greater potential for long term survival and performance of mixture plantings. The London, Ontario site, with a relatively moderate climate, supported the best green roof growth and performance compared to the cooler and drier Calgary and the rainier Halifax. [ABSTRACT FROM AUTHOR]

Building on the advances in molecular technology, two genetic based tools are being developedby Biosecurity Queensland to improve conventional invasive plant detection, monitoring andcontrol. [...]

The dropseed gall-forming nematode, Afrina sporoboliae sp. n., is described from seed galls of Sporobolus cryptandrus (Poaceae: Chloridoideae: Sporobolinae) collected in Idaho, USA. This is the third report of an Afrina species in North America and the first report of this genus in a natural plant population on this continent. Morphological, morphometric, and molecular analyses placed this nematode in genus Afrina and demonstrated that it differs from Afrina hyparrheniae and Afrina spermophaga by having longer body and stylet lengths for females and males, and from Afrina wevelli by the absence of tip irregularities on the tails of female and presence of lips noticeably protruding beyond the body contour. The new species has several characters that overlap with Afrina tumefaciens, but differs from this species by inducing seed galls, whereas Afrina tumefaciens induces ovoid galls on stems, leaves, and in flower heads. Evolutionary relationships of Afrina sporoboliae sp. n. with other representatives of the family Anguinidae are presented based on analysis of the internal transcribed spacer (ITS) 1-5.8S-ITS2 rRNA and the D2-D3 regions of the rRNA genes. Analysis of 270 sequences of the coxl gene from 25 populations of Afrina sporoboliae sp. n. revealed seven haplotypes with sequence divergence up to 5%. This study did not demonstrate a significant positive relationship between genetic difference and geographic distance. Seed gall nematodes are important quarantine pests in many countries. The association of this and other seed gall nematodes with Rathayibacter species and their ability to serve as vectors, especially of R. toxicus, is of concern for U.S. agriculture. [ABSTRACT FROM AUTHOR]

The existing variations and diversity of Sporobolus spicatus and its suitability as turf grass needed to be assessed for conservation and to combat salinity problem. For this purpose, various ecotypes of Sporobolus spicatus were investigated by conducting mowing tests in the year 2013 under UAE climatic conditions. Fifty ecotypes of Sporobolus spicatus were cut at various heights, i.e. 1, 2, 3, 4 and 5 cm. Significant differences were found among various ecotypes and mowing heights for different growth and quality parameters including green cover, canopy stiffness, leaf length and width. Most of the ecotypes gave better performance at mowing height 3 and 4 cm, which comply with the standard mowing height for turf grasses. Ecotypes RS2, MZADS1 and SAADS1 resulted in the best performance against mowing shock. Based on their performance, these ecotypes could be used for turf purposes in public landscape under saline environments. [ABSTRACT FROM AUTHOR]

A Bacillus velezensis strain from the rhizosphere of Sporobolus airoides (Torr.) Torr., a grass in central-north México, was isolated during a biocontrol of phytopathogens scrutiny study. The 2A-2B strain exhibited at least 60% of growth inhibition of virulent isolates of phytopathogens causing root rot. These phytopathogens include Phytophthora capsici, Fusarium solani, Fusarium oxysporum and Rhizoctonia solani. Furthermore, the 2A-2B strain is an indolacetic acid producer, and a plant inducer of PR1, which is an induced systemic resistance related gene in chili pepper plantlets. Whole genome sequencing was performed to generate a draft genome assembly of 3.953 MB with 46.36% of GC content, and a N50 of 294,737. The genome contains 3713 protein coding genes and 89 RNA genes. Moreover, comparative genome analysis revealed that the 2A-2B strain had the greatest identity (98.4%) with Bacillus velezensis. [ABSTRACT FROM AUTHOR]

In many arid and semiarid regions worldwide, high levels of soil salinity is a key driver of land degradation, as well as a key impediment to re-establishing plant cover. Combating land degradation and erosion associated with soil salinity requires experimental determination of plant species that can grow in soils with high levels of salinity and can be used to re-establish plant cover. Herein, we evaluated the responses of untested candidate cultivars of two halophytic grass species to high soil salinity: alkali sacaton (Sporobolus airoidesTorr.) and seashore paspalum (Paspalum vaginatumSwartz). We evaluated the growth responses of both species in a greenhouse under control (no-salt) and various levels of NaCl salinity (EC 8, 16, 24, 32, 40, and 48 dSm−1) using Hoagland solution in a hydroponics system in a randomized complete block design trial. At all salinity levels, sacaton grass had a greater shoot height, shorter root length, lower shoot fresh and dry weights, and poorer color and general quality compared to seashore paspalum. The shoot fresh and dry weights of both grasses were greatest at the low to medium levels of salinity, with the greatest response observed at EC 16 dSm−1. At the highest level, salinity significantly reduced shoot fresh and dry weights of both grasses. Because growth of both halophytic species exhibited high tolerance to salinity stress and were stimulated under low to medium levels of salinity, both species could be considered suitable candidates for re-establishing plant cover in drylands to combat desertification and land degradation associated with high levels of soil salinity. [ABSTRACT FROM PUBLISHER]

Seedlings ofS. robustuswere exposed to increasing NaCl concentrations (0, 50, 100, 150, 200, 250, and 300 mM) for 50, 100, and 150 days, in greenhouse conditions. Total dry weight and salt tolerance index decreased gradually with increasing NaCl concentrations. The optimum growth ofS. robustus(4.12 to 5.25 g · plant−1) was obtained between 0 and 150 mM at 150 days after salt stress. Foliar chlorophyll a and total chlorophyll contents increased with NaCl concentration at 50 days after treatment. There was no significant effect of salinity on chlorophyll a, b and total chlorophyll contents at 100 and 150 days after treatment. Higher Na contents were found in the shoots as compared to the roots. The Na content increased, while K decreased with increasing NaCl concentrations, suggesting competitive inhibition between absorptions of Na and K as a consequence, the K/Na ratios in shoots and roots decreased with increasing salinity. The proline contents inS. robustuswere more pronounced at 300 mM (2.02 µmol/g), 250 mM (2.64 µmol/g), and 200 mM NaCl concentrations (2.98 µmol/g) for 50, 100, and 150 days, respectively, as compared to the treatment without added NaCl. Overall,S. robustuscould be considered as salt tolerant on the basis of their performance in biomass production, accumulation of Na, similar foliar chlorophyll a, chlorophyll b and total chlorophyll contents, and accumulation of proline with increasing salinity. The potential ability ofS. robustusto accumulate significant amounts of Na makes this halophyte promising as a desalinization tool of salted soils. [ABSTRACT FROM AUTHOR]

Growing season aridity and livestock grazing seasonality can influence primary productivity of perennial grasses in dryland systems. For this study, we used a long-term dataset (1967–2004) to investigate the independent and joint effects of growing season aridity and season of grazing (yearlong continuous, fall, winter/spring, or summer season grazing) on the mean annual primary productivity of the perennial grasses Bouteloua eriopoda (black grama), Aristida spp. (threeawn), and Sporobolus spp. (dropseed) in a southwestern United States Chihuahuan Desert rangeland system. Over the 37-year study period, total perennial grass biomass decreased as aridity increased, but the extent of this relationship depended upon season of grazing and specific grass taxon. Aridity-related decreases in total perennial grass biomass were most severe in the summer grazing treatment. Our findings indicate that over time, summer and fall grazing can potentially exacerbate the negative effects of increasing aridity on perennial grass biomass. As arid and semi-arid rangelands globally face increasing aridity associated with a changing climate, land managers can modulate the season of grazing, dependent on dominant taxa present, to minimize these effects. Our study and those from other arid land locations indicate continuous grazing at light to conservative intensities can better sustain key perennial grasses than strategies involving concentrated seasons of grazing. However, growing season aridity levels must also be taken into consideration. • Temporal variation of Aridity in Chihuahuan Desert. • Grazing Seasonality Treatments influencing perennial grasses. • Drylands jointly impacted by temporal aridity and grazing seasonality treatments. • Black grama and Sporobolus primary forage in CDRRC. [ABSTRACT FROM AUTHOR]

Invasive plant species diminish ecosystem integrity and limit restoration success when they compete with reintroduced native species. The invasive annual forb halogeton (Halogeton glomeratus (M. Bieb.) C.A. Mey. [Chenopodiaceae]) is increasing in abundance on disturbed lands and energy extraction sites in the Intermountain West. Successful seedings in the presence of halogeton in the past relied on competitive nonnative forage species. Because disturbance increases nutrient availability in otherwise stressful environments, we hypothesized that annual native species may be more competitive at the seedling stage than are perennial natives. We hypothesized that annuals would increase aboveground growth in the presence of the exotic while perennials would increase allocation to root growth. We documented growth and survival of halogeton in the presence of 10 species native to the western North American basin shrublands and in monocultures. Sporobolus cryptandrus (Torr.) A. Gray (Poaceae), Gaillardia aristata Pursh (Asteraceae), and Helianthus annuus L. (Asteraceae) reduced survival of halogeton (< 30%). Sporobolus and Gaillardia had greater biomass while Helianthus grew taller in the presence of halogeton than when grown with conspecifics. Halogeton aboveground growth was less when grown with H. annuus and Cleome serrulata Pursh (Capparaceae) (2 annual forbs). Annuals that demonstrated rapid biomass production also limited survival of halogeton. In general, perennials did not differ in aboveground tissue allocation in competition with halogeton. We suggest reclamation seedling establishment may be improved by including native annuals with the potential for rapid aboveground growth on arid land restoration sites where halogeton seedbanks persist. [ABSTRACT FROM AUTHOR]

Natural populations of a desert halophyte Sporobolus ioclados were investigated to explore morpho-anatomical and physiological modifications at differently salt-affected habitats. Derawar Fort (DF) was the least affected site, Trawaywala Toba and Bailahwala Dahar (BD) were moderately saline sites and Ladam Sir (LS) and Pati Sir (PS) were highly saline sites. At root level, S. ioclados showed increased root cross-sectional area, epidermal and endodermal thicknesses, and greater proportion of cortical parenchyma as salinity level of the habitat increased. Sclerification of outer cortex was visible only at the highest saline site. Decreased stem area, epidermal cell area, cortical and vascular bundle cell area, and increased hypodermal thickness at stem level were recorded with increase in the salinity level of the habitats. At leaf level, S. ioclados showed smaller and thicker leaves, increased epidermis thickness, and well-developed bulliform cells, increased mesophyll area and increased trichome density under high salinities. The plants at high salinities were better adapted in terms of growth, exclusion, internal structure, and restricted uptake of Na + by roots, accompanied by increased concentration of K + and Ca 2+ in shoots. All these changes may be an evolutionary strategy that has been developed by the S. ioclados plants during the long process of evolution. [ABSTRACT FROM AUTHOR]

In a small plot study we used a systematic additive design to evaluate at what severity and frequency of defoliation sideoats grama (Bouteloua curtipendula) would remain competitive and recover from defoliation while growing with meadow dropseed (Sporobolus compositus). In the 3-year study plants were transplanted from pots into the experimental design when equal in size. WhenB. curtipendulawas selectively defoliated moderately or severely, at both 30- and 60-day intervals, it still produced as much as when undefoliated growing with undefoliatedS. compositus. Moderately defoliatedB. curtipenduladid not reduce biomass yield ofS. compositusgrowing with it compared to whenS. composituswas growing alone. When both plants were non-selectively defoliated severely,S. compositusresponded very weakly andB. curtipendularecovered at the same rate as it had under the other defoliation treatments. The total biomass produced by both species growing together was highest whenB. curtipendulawas moderately defoliated. As soil moisture was not limited in this experiment we do not believe our results refute the hypothesis that selective grazing by livestock in these ecosystems has contributed to a reduction ofB. curtipendularelative toS. compositus. AlthoughS. composituswas reduced more thanB. curtipendulaby heavy nonselective defoliation this treatment is unlikely to produce desirable results in the long term as the highest total vegetation production occurred whenB. curtipendulawas moderately defoliated. [ABSTRACT FROM AUTHOR]

A selected germplasm release of sand dropseed (Sporobolus cryptandrus (Torr.) A. Gray [Poaceae]) was cooperatively released in 2015 by the South Texas Natives project and the USDA NRCS E "Kika" de la Garza Plant Materials Center in Kingsville, Texas. This release is intended for use in range and wildlife plantings, right-of-way reseeding, and critical site seedings. Nueces Germplasm comprises 5 populations of sand dropseed collected from native plants in the Rio Grande Plains, Coastal Sand Plains, and Gulf Coast Prairies and Marshes ecoregions of southern Texas. Selections were made from 26 accessions of sand dropseed based on plant performance data collected over 2 y at 3 evaluation sites representative of the intended area of use of the germplasm across South Texas. Following selection, outplants were grown from the original seed stock of each of the 5 accessions, were increased in isolation, and then blended for release in order to preserve genetic integrity of each source population. Nueces Germplasm represents the first selected, ecotypic seed source of sand dropseed for use in South Texas. [ABSTRACT FROM AUTHOR]