Hyparrhenia Hirta Research Articles

Critical notes on grasses (Poaceae) of Madeira, Portugal

As a result of fieldwork in the island of Madeira (Portugal) in the autumn of 2021 and the spring of 2022, nine non-native grasses are newly reported: Axonopus fissifolius, Chloris pycnothrix, Digitaria radicosa, D. violascens, Eragrostis multicaulis, Nassella hyalina, Paspalum notatum, P. urvillei and Sporobolus aff. fertilis. All are at least locally naturalized in the island of Madeira and, elsewhere in the world, they are often considered invasive species or weeds. In addition, the identity of species from the Hyparrhenia hirta and Setaria verticillata complexes is discussed. Finally, some miscellaneous notes on other noteworthy grasses are also presented.

Competition between alien and native species in xerothermic steno-Mediterranean grasslands: Cenchrus setaceus and Hyparrhenia hirta in Sicily and southern Italy

AbstractPerennial dry grassland communities, vital for plant biodiversity conservation in the Mediterranean, often harbor rare and endangered species. However, these habitats face threats, including the invasion of alien species. Cenchrus setaceus, a highly invasive grass, is spreading in the Mediterranean region. Historical records and observations document its establishment and invasiveness across various Italian regions. This study investigates the impact of C. setaceus on native grasslands dominated by Hyparrhenia hirta. We assessed the impact of C. setaceus invasion on plant biodiversity in Sicily and southern Italy, and we identified and characterized plant species’ composition using Ellenberg indicator values. The intention to analyze species richness, diversity, and ecological indicators is also emphasized. Starting from the use of the phytosociological method, multivariate analysis and Ellenberg indicator values to assess the impact of C. setaceus on grasslands composition were considered. There are several similarities and differences in diversity, floristic composition, and ecological traits between the two grassland types. A deep comparison with central European studies and evaluation of the impact of C. setaceus on species richness and community dynamics in Mediterranean habitats were concluded. Although C. setaceus is invading native grasslands, it does not drastically reduce species richness. The ecological implications of the invasion are explored, urging ongoing monitoring and collaborative efforts for effective conservation. The importance of interdisciplinary cooperation is highlighted to address the threat of invasive species and sustain the biodiversity of Mediterranean grasslands.

Diet preferences of common warthogs (Phacochoerus africanus) in Gassi and Haro Aba Diko controlled hunting areas, Western Ethiopia

To assess feeding ecology and diet preferences of common warthogs (Phacochoerus africanus (Gmelin, 1788), the study was conducted in Gassi Controlled Area (GCHA) and in Haro Aba Diko Controlled Hunting Area (HADCHA) from May 2017 to June 2018. Diet composition of common warthog was determined using feeding quadrat and microhistological methods. From the leaf cuticle fragments observed of feces, 41 and 45 plant species were recognized as annual dietary components of common warthog in GCHA and HADCHA, respectively. Uncertainty of epidermal fragments and fine digestion, led certain forage species consumed by warthogs to be unidentified. In Gassi Controlled Hunting Area, Cynodon nlemfuensis (75.5%), Cynodon dactylon (69%), and Cyperus fischerianus (47%) had the higher relative frequency occurrence (RFO) in the feces of the animal during the wet season. In Haro Aba Diko Controlled Hunting Area, C. nlemfuensis (76.5%), C. dactylon (73.5%) and H. rufa (57.5%) were the top three forage species with higher RFO in the feces of the warthog during the dry season. During the wet season in GCHA, C. fischerianus, D. abyssinica, C. dactylon, C. nlemfuensis, Hyparrhenia rufa, A. abyssinicus, Sesbania sesban and Diplolophium africanum were identified as the staple forage species of common warthogs. In HADCHA, C. fischerianus, D. abyssinica, C. dactylon, C. nlemfuensis, H. rufa, H. hirta, S. poiretiana, A. abyssinicus, and S. sesban were identified as the staple forage species of warthogs during the wet season. In GCHAC. dactylon, C. nlemfuensis and A. abyssinicus were the top three species which showed high acceptability during the wet and dry seasons. Hyparrhenia hirta, was high acceptability during the wet season which was less acceptability during the dry season but the difference was not significant. In HADCHA C. fischerianus, D. abyssinica, C. dactylon, and C. nlemfuensis, showed high acceptability during both seasons. Therefore, common warthogs foraged on wide range of food resources of graminoids, forbs, and shrubs in the study areas. Certain staple forage species were frequently preferred, because of their compatibility with the physiology of warthogs.

Phytosociology of Atractylis cancellata and Micromeria microphylla communities in southern Italy with insights on the xerothermic steno-Mediterranean grasslands high-rank syntaxa

In the present paper a phytosociological study on the dry grassland communities identified in the western sector of the Murgia Plateau (Murgia delle Gravine) and in the Lucanian badlands territory is presented. Forty vegetation releves were carried out using the Braun-Blanquet phytosociological approach. Two new associations characterized by a therophytic dominance, namely Lysimachio foeminae-Atractylidetum cancellatae and Campanulo erini-Micromerietum microphyllae, are described and discussed from a syntaxonomic and biogeographic viewpoint. In addition, new phytosociological data concerning the Petrosedum ochroleucum communities developed on limestone outcrops, the perennial Hyparrhenia hirta steppe-like grasslands of the low-altitude areas of the Murgia hills and the small-size Brachypodium distachyum therophytic communities are presented.

Rangeland utilization by beef cattle in the dry Savanna areas of Southern Africa

A literature review was done on the selection and utilization of grass species by beef cattle in the Limpopo province. The literature study was complimented by research done on the Towoomba Research station and the University of Limpopo, both in Limpopo Province, in South Africa. The Province is well known for its low rainfall and good quality rangeland. The main aim was to categorize the most important grass species in different utilization (palatability) classes. The thirteen grass species which were under investigation could be classified as follows: Highly palatable species: Panicum maximum and Urochloa mosambicensis; Palatable species: Digitaria eriantha, Heteropogon contortus, Schmidtia pappophoroides and Themeda triandra. Less palatable: Trachypogon spicatus and Themeda triandra and Least palatable: Eragrostis rigidior, Hyparrhenia hirta, Pogonarthria squarrosa, Melinus repens and the Aristida species.

Assessing the effectiveness of Hyparrhenia hirta in the rehabilitation of the ecosystem of a gold mine dump

The mining of gold is associated with several environmental challenges such as acid mine drainage, release of toxic metals which are associated to tailing sediments and have adversely impacted human health and the ecosystem. With increasing global population that is faced with limited land resources for agricultural activities, there is need for land restoration through effective rehabilitation of contaminated soils. The introduction of Hyparrhenia hirta, an indigenous grass specie as a phytoremediation technique for in situ rehabilitation of degraded soil is not only an economically viable approach but also environmentally friendly. Hyparrhenia hirta being a tufted and wiry perennial grass that is invasive with deep root system often aid in stabilizing the ecosystem owing to their self-fertile and drought resistant potentials that support that prevalence in harsh conditions at mine dump sites. In this study, mine tailings at Gold One Mine, Ekuhurleni, South Africa were assessed for heavy metal contents at the same time analysing the uptake of such heavy metals by Hyparrhenia hirta grass specie. The total metal mean concentrations was high (4023.67 mg/kg) for Hyparrhenia hirta which absorbed more of the following mean metal concentrations: 46.10 mg/kg for Cu; 40.08 mg/kg for Zn; 859.12 mg/kg for Pb; 618.26 mg/kg for Cr; 151.70 mg/kg for Co and 2308.41 mg/kg for Ni. The tailings were strongly acidic with a pH range of 3.86 – 4.34. These heavy metals despite the acidic environments were successfully absorbed by Hyparrhenia hirta grass specie. Along these lines Hyparrhenia hirta was discovered reasonable for re-vegetation of mine tailings dump as it has the capacity to hold together tailings sediments against wind and water erosion.

Suitability of Wild Host Plants and Firewood as Hosts of Prostephanus truncatus (Coleoptera: Bostrichidae) in Mozambique.

Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) populations are maintained in wild host plants such as trees that act as pest reservoirs from where beetle infestation of maize granaries take place. In this study, we assessed the suitability of plant species sold and transported as firewood as well as other plant species in Mozambique as hosts for P. truncatus. Prostephanus truncatus was only recorded from three tree species, which are sold as firewood, i.e., Brachystegia spiciformis, Strychnos spinosa, and Colophospermum mopane. The pest survived and bred in 13 tree and 7 grass species. Dry wood of several tree species and the grasses Acroceras macrum and Hyparrhenia hirta were suitable hosts for pest development. Sale and transport of certain firewood species may be an important driver of the spread of this pest. The importance of dry maize stalks and several grass species in sustaining pest populations is described for the first time. Several grass species are used as thatch or fencing material and, together with maize crop residues close to small-scale granaries, may provide significant sources of beetle infestation.

The role of seedbanks in invasions by Hyparrhenia hirta (L.) Stapf in Australia

Hyparrhenia hirta (L.) Stapf (also known as Coolatai grass, South African bluestem or thatching grass) has become a serious invasive weed in Australia. Within its native range, it is generally regarded as a useful grass particularly for thatching, and seed production is low with a low soil seed bank of from 2 to 200seedsm–2. Several hundred accessions of H. hirta were deliberately introduced into Australia up until the 1980s and nearly all were discarded because of poor seed production. However, at least one introduction in the 1890s in northern New South Wales (NSW), Australia, has possibly contributed to the present serious weed problem. Annual seed production from roadside stands in northern NSW ranged from 7000 to 92000seedsm–2 in 2015. The soil seed bank under dense H. hirta infestations in the same region in 2006 and 2007, was found to be ~30000seedsm–2 mostly confined to the top 2cm, with few dormant seeds and a large reduction of these numbers over the next 12 months when further seed input was prevented. Similar studies of other perennial grass weeds have found seed banks of similar sizes, but dormancy mechanisms ensure that their seed banks last for at least 10 years without further seed input. These results suggest that the present weedy populations of H. hirta have dramatically increased fecundity enabling a large seed bank to develop beneath dense stands. The development of seed dormancy and consequently a long-lived seed bank would make this weed even more difficult to control. Until seed dormancy develops, control of H. hirta in northern NSW can be effective provided further input into the seed bank can be prevented.

Field studies on occurrence, alternate hosts and mortality factors of Date Palm Mite, Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae)

The occurrence of date palm mite (DPM), Oligonychus afrasiaticus, its association with other mite species and alternate host plants were studied in nine provinces of Saudi Arabia during eight consecutive years (2011–2018). In addition, different mortality factors of DPM during the fruiting season were assessed in Riyadh city. The results showed that all DPM developmental stages were recorded on date palm young-aged fronds as well as grasses growing underneath the trees during off-fruit periods, even in severe winters. Interestingly, DPM was found only on narrow leaf alternate host plant species belonging to the families Arecaceae and Poaceae. Moreover, Hyphaene thebaica, Phoenix canariensis, Cenchrus ciliaris, Dichanthium annulatum, Hilaria sp., Hyparrhenia hirta, Pennisetum ciliarae, P. divisum, Pennisetum sp. and Aeluropus littoralis were reported for the first time as alternate host plants of the DPM. Two phytophagous mites, Eutetranychus orientalis and E. palmatus (Tetranychidae), and the predatory mite Spinibdella cronini (Bdellidae) were found associated with DPM on date fruits. However, the phytoseiid mite Cydnoseius negevi was found on the grasses growing under the trees. Amongst mortality factors, pathogens followed by predators were responsible of deaths in different DPM stages. However, the unknown environmental factors caused maximum mortality of all DPM stages than any other factor. Based on the obtained data, it is suggested that young-aged fronds should be sampled prior to fruit setting for early detection of DPM and consequently should be chemically treated during the off-season. In addition, the alternate host plants as well as date palm trees growing along the roadside should be chemically treated as they may be a source of DPM. Also, more attention should be given to search and conserve indigenous predators which can be used efficiently against DPM. It is anticipated that such data can provide valuable information to improve IPM program for controlling DPM in other regions of Saudi Arabia.

Exploring the potential of wild perennial grasses as a biomass source in semi-arid Mediterranean environments

In Mediterranean environments, few perennial grass species are available for cultivation in rainfed systems and marginal lands, where plants with excellent adaptation are required. The aim of the present work was to determine the potentiality of five native Mediterranean perennial grasses for lignocellulosic biomass production. Wild accessions of three hemicryptophytes (Ampelodesmos mauritanicus, Hyparrhenia hirta, and Piptatherum miliaceum) and two geophytes (Saccharum spontaneum ssp. aegyptiacum and Sorghum halepense) were collected at three Mediterranean sites (Sicily, Sardinia and Majorca), and their morphological, physiological, productivity and quality traits were evaluated in the field. The species differed in height, with S. spontaneum and A. mauritanicus being the tallest. The leaf mass ratio ranged from 0.23 to 1.0 g g–1 among species. Maximum net photosynthesis was measured in the C4 species S. spontaneum and S. halepense (26.6 and 23.8 mmol CO2 m–2 s–1, respectively). A. mauritanicus showed the lowest transpiration rate and the highest instantaneous water use efficiency (2.7 mmol H2O m–2 s–1 and 6.9 mmol CO2 mmol H2O–1, respectively). S. spontaneum was the most productive species, yielding more than 18 Mg DM ha–1 as a three-year average. The highest content of acid detergent lignin was found in P. miliaceum, while A. mauritanicus was the species richest in hemicellulose and cellulose and poorest in ash. S. spontaneum showed the highest moisture content at harvest. Overall, the studied species showed interesting morphological, physiological, productive and qualitative traits. Nevertheless, additional research is necessary to investigate their long-term performance under different management strategies.

The unspecificity of the relationships between the invasive Pennisetum setaceum and mycorrhizal fungi may provide advantages during its establishment at semiarid Mediterranean sites

The involvement of mutualistic plant-fungal interactions in invasion processes, especially in some climatic regions including semiarid areas, has not been sufficiently investigated. We compared the arbuscular mycorrhizal fungi (AMF) communities hosted by the invasive plant Pennisetum setaceum with those from the co-occurring native Hyparrhenia hirta at five Mediterranean semiarid locations with different edaphic characteristics. Illumina technology was used to investigate the AMF communities in the roots. The subsequent multivariate analysis showed that native and non-native host plants shared a similar AMF community, whereas the invaded locations differed in AMF communities harbored in the plant roots. The indicator species analysis revealed the absence of indicator virtual taxa for the fungal communities of the roots of native or invasive plants. In contrast, different numbers of indicator species were recorded in different sampling locations. According to the canonical correspondence analysis, the variability in the AMF communities between sampling sites was related to changes in soil total carbon, electrical conductivity, respiration, and protease and urease activities. These findings reveal the unspecificity of P. setaceum in relation to its association with the AMF community encountered in the invaded locations, which could have facilitated its successful establishment and spread.

Habitat, occurrence and conservation status of the Saharo-Macaronesian and Southern-Mediterranean element Fagonia cretica L. (Zygophyllaceae) in Italy

Fagonia cretica L. is an important component of Mediterranean dry grasslands and a rare and isolated species of Italian flora. In this study, an assessment is presented on the distribution, habitat, and conservation status of F. cretica in Italy. The results of field investigation and herbarium analysis show that this species grows in a small area within the southern Calabria region characterized by a warmest and driest Mediterranean climate on the Italian peninsula. F. cretica is a semi-desert plant species growing in Italy in only one peripheral and isolated population at the northern limit of its distribution. Plant community analysis, using the phytosociological method, shows that F. cretica grows in wintergreen perennial dry grasslands dominated by Lygeum spartum and Hyparrhenia hirta. F. cretica plant communities are located in thermo-xeric habits such as south-, southeast- and east-facing slopes on clays and sandy clays in southern Calabria. The population of F. cretica is fragmented in six neighbouring localities, with two of which belonging to a Site of Community Importance (SCI). The conservation status of F. cretica population is not very good, and is defined as “Critically Endangered” in accordance with IUCN criteria. There are many threats affecting the F. cretica population in Italy, primarily the changes in land uses due to urban expansion and reforestation with exotic plants. The southern end of the Italian peninsula hosts other plants from thermo-xeric habits that do not adapt to the current local climate. This territory can be considered as a microrefugia for plants currently distributed in the arid territory of the southern Mediterranean. These results contribute to the discussion of some conservation measures, and the possibility of establishing a micro-reserve. For all these reasons, we propose to include F. cretica in the lists of protected plant species at regional (Calabria) and country (Italy) scales in Italy.

Molecular phylogenetics and definition of the Acrapex minima Janse group (Lepidoptera, Noctuidae, Apameini, Sesamiina) with the description of four new species from the Afrotropics

SummaryFive morphologically similar species of Acrapex Hampson (Lepidoptera, Noctuidae, Noctuinae, Apameini), from sub-Saharan Africa are reviewed, including four new species that are described: Acrapex mondogeneta Le Ru n. sp., A. mubale Le Ru n. sp., A. robe Le Ru n. sp. and A. rubona Le Ru n. sp. These five species belong to a species complex that we hereby define as the Acrapex minima group. Host plants of three species are recorded; Acrapex minima is recorded for the first time on a host plant, Digitaria natalensis Stent; A. mondogeneta on Hyparrhenia hirta (L.) Stapf and A. rubona on Imperata cylindrica (L.) P. Beauv. We also conducted molecular phylogenetics (using both Bayesian inference and maximum likelihood) and molecular species delimitation analyses (Poisson tree processes) on a six gene multi-marker dataset (four mitochondrial and two nuclear gene fragments; 4582 nucleotides in length) of 42 specimens and 22 species, including 23 specimens from the Acrapex minima group. The results of the corresponding analyses support the monophyly of the group and the species status of the newly described taxa.

Preparation of poly(methyl methacrylate)–grafted Hyparrhenia hirta for methyl red removal from colored solutions

ABSTRACTPoly(methyl methacrylate)–grafted Hyparrhenia hirta (PMMA-g-Hh) biopolymer was prepared through radical polymerization using potassium persulfate (KPS) and applied in adsorption of methyl red from colored solutions. Solvent amount, initiator concentration, monomer concentration, temperature, and reaction time were the reaction parameters investigated for grafting. The biopolymer was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and x-ray diffraction spectroscopy (XRD). The adsorption process was investigated with respect to pH, contact time, initial concentration, adsorbent dosage, and temperature. The optimum adsorption parameters were pH 6, contact time 90 min, adsorbent dosage 0.6 g, and initial concentration 50 mg/L. The Langmuir adsorption model best fitted the adsorption process, with maximum adsorption capacities of 19.95, 6.89, and 4.02 mg/g at adsorbent dosages of 0.2, 0.6, and 1.0 g, respectively. The pseudo-second-order model described the kinetics data better. The adsorption process was physical, spontaneous, and endothermic. The adsorbent was still active after 10 adsorption-desorption cycles, showing its suitability for use in colored solutions treatment.

Why non-native grasses pose a critical emerging threat to biodiversity conservation, habitat connectivity and agricultural production in multifunctional rural landscapes

ContextLandscape-scale conservation planning is key to the protection of biodiversity globally. Central to this approach is the development of multifunctional rural landscapes (MRLs) that maintain the viability of natural ecosystems and promote animal and plant dispersal alongside agricultural land uses.ObjectivesWe investigate evidence that non-native grasses (NNGs) in rangelands and other low-intensity agricultural systems pose a critical threat to landscape conservation initiatives in MRLs both in Australia and globally.MethodsWe first establish a simple socio-ecological model that classifies different rural landscape elements within typical MRLs based on their joint conservation and agro-economic value. We then quantify the impacts of eight Australian NNGs (Andropogon gayanus, Cenchrus ciliaris, Eragrostis curvula, Hyparrhenia hirta, Nassella neesiana, Nassella trichotoma, Phalaris aquatica and Urochloa mutica) on different landscape elements and then classify and describe the socio-ecological transformations that result at the MRL scale.ResultsOur data indicate that two broad classes of NNGs exist. The first reduces both conservation and agro-economic value (‘co-degrading’ species) of invaded landscapes, while the second improves agro-economic value at the expense of conservation value (‘trade-off’ species). Crucially, however, both classes cause hardening of the landscape matrix, agricultural intensification, reduced habitat connectivity, and the loss of multi-value land use types that are vital for landscape conservation.ConclusionsNNGs drive socio-ecological transformations that pose a growing threat to landscape-scale connectivity and conservation initiatives in Australia and globally. There is an urgent need for further research into the impacts of NNGs on habitat connectivity and biodiversity within multifunctional landscapes, and the socio-ecological goals that can be achieved when landscape transformation and degradation by these species is unavoidable.

Evaluation of six candidate DNA barcode loci for identification of five important invasive grasses in eastern Australia.

Invasive grass weeds reduce farm productivity, threaten biodiversity, and increase weed control costs. Identification of invasive grasses from native grasses has generally relied on the morphological examination of grass floral material. DNA barcoding may provide an alternative means to identify co-occurring native and invasive grasses, particularly during early growth stages when floral characters are unavailable for analysis. However, there are no universal loci available for grass barcoding. We herein evaluated the utility of six candidate loci (atpF intron, matK, ndhK-ndhC, psbE—petL, ETS and ITS) for barcode identification of several economically important invasive grass species frequently found among native grasses in eastern Australia. We evaluated these loci in 66 specimens representing five invasive grass species (Chloris gayana, Eragrostis curvula, Hyparrhenia hirta, Nassella neesiana, Nassella trichotoma) and seven native grass species. Our results indicated that, while no single locus can be universally used as a DNA barcode for distinguishing the grass species examined in this study, two plastid loci (atpF and matK) showed good distinguishing power to separate most of the taxa examined, and could be used as a dual locus to distinguish several of the invasive from the native species. Low PCR success rates were evidenced among two nuclear loci (ETS and ITS), and few species were amplified at these loci, however ETS was able to genetically distinguish the two important invasive Nassella species. Multiple loci analyses also suggested that ETS played a crucial role in allowing identification of the two Nassella species in the multiple loci combinations.

Striking alterations in the soil bacterial community structure and functioning of the biological N cycle induced by Pennisetum setaceum invasion in a semiarid environment

The objective of this study was to determine whether native and invasive plants harbor different bacterial communities in their rhizospheres and whether there are bacterial indicator species associated with the invasive rhizosphere. Additionally, physico-chemical, biochemical, and biological properties have been determined in the native and invasive rhizospheres in order to ascertain the relationships between these soil properties and the rhizosphere bacterial communities. We carried out a study in five independent locations under Mediterranean semiarid conditions, where the native Hyparrhenia hirta is being displaced by Pennisetum setaceum. Partial 16S rRNA genes of the rhizosphere bacterial communities were amplified and 454-pyrosequenced. Principal coordinate analysis revealed differences in the composition and structure of the rhizosphere bacterial communities between native and invasive plants, the values of the richness index being higher in the invasive microbial community. Rhizosphere microbial community structure was also influenced by invaded location. The indicator species analysis showed a higher number of indicators for the invasive community at all the taxonomic levels studied, the genus Ohtaekwangia being the most abundant indicator. As shown by canonical correspondence analysis, the protease and dehydrogenase activities and soil respiration were related to the rhizosphere bacterial community of invasive plant. However, only protease activity was significantly affected by the plant type, being higher in the invasive plant rhizosphere. Our results show that P. setaceum invasion has produced an intense interaction with the soil bacterial community, shifting its structure, composition, and protease activity related to N cycling, which may be altering the function of the invaded ecosystem.

Carbon storage of Mediterranean grasslands

Secondary grasslands are one of the most common vegetation types worldwide. In Europe, and in the Mediterranean basin, human activities have transformed many woodlands into secondary grasslands. Despite their recognized role in the global carbon cycle, very few data are available for estimating the biomass of Mediterranean grasslands. We developed linear regression models in order to predict the biomass of two native Mediterranean grasses ( Ampelodesmos mauritanicus and Hyparrhenia hirta ) and an invasive alien grass ( Pennisetum setaceum ). Ampelodesmos mauritanicus is very common throughout the Mediterranean basin, mostly on north-facing slopes, H. hirta characterizes thermo-xeric grasslands, while P. setaceum is an alien species that is rapidly spreading along coastal areas. The measured morphometric attributes of individual plants as potential predictors were considered. The validation results corroborate the ability of the established models to predict above ground and total biomass of A. mauritanicus and P. setaceum . We also evaluated the total biomass per hectare for each species. The highest biomass per hectare was found for A. mauritanicus , whereas biomass was higher for H. hirta than for P. setaceum . The replacement of H. hirta by P. setaceum may reduce the total carbon storage in the ecosystem; however, P. setaceum allocates more resources to the roots, thus increasing the more stable and durable pool of carbon in grasslands.

Evaluation of Trace Metal Profile in Cymbopogon validus and Hyparrhenia hirta Used as Traditional Herbs from Environmentally Diverse Region of Komga, South Africa.

FAAS was used for the analysis of trace metals in fresh and dry plant parts of Cymbopogon validus and Hyparrhenia hirta species with the aim of determining the trace metals concentrations in selected traditional plants consumed in Eastern Cape, South Africa. The trace metal concentration (mg/kg) in the samples of dry Cymbopogon validus leaves (DCVL) showed Cu of 12.40 ± 1.000; Zn of 2.42 ± 0.401; Fe of 2.50 ± 0.410; Mn of 1.31 ± 0.210; Pb of 3.36 ± 0.401 mg/kg, while the samples of fresh Hyparrhenia hirta flowers (FHHF) gave Cu of 9.77 ± 0.610; Zn of 0.70 ± 0.200; Fe of 2.11 ± 0.200; Mn of 1.15 ± 0.080; Pb of 3.15 ± 0.100 mg/kg. Abundance of metal concentrations follows the order: Cu > Fe > Pb > Mn > Zn in the flower samples of Cymbopogon validus and Hyparrhenia hirta species. The concentrations of trace metals in both plant parts were below the permissible limits (PL) set by WHO. It is suggested that pharmacovigilance be carried out periodically to improve the quality, safety, and efficiency of various herbal products.

Competition between a Lawn-Forming Cynodon dactylon and a Tufted Grass Species Hyparrhenia hirta on a South-African Dystrophic Savanna.

South African savanna grasslands are often characterised by indigestible tufted grass species whereas lawn grasses are far more desirable in terms of herbivore sustenance. We aimed to investigate the role of nutrients and/or the disturbance (grazing, trampling) by herbivores on the formation of grazing lawns. We conducted a series of common garden experiments to test the effect of nutrients on interspecific competition between a typical lawn-forming grass species (Cynodon dactylon) and a species that is frequently found outside grazing lawns (Hyparrhenia hirta), and tested for the effect of herbivore disturbance in the form of trampling and clipping. We also performed a vegetation and herbivore survey to apply experimentally derived insights to field observations. Our results showed that interspecific competition was not affected by soil nutrient concentrations. C. dactylon did show much more resilience to disturbance than H. hirta, presumably due to the regenerative capacity of its rhizomes. Results from the field survey were in line with these findings, describing a correlation between herbivore pressure and C. dactylon abundance. We conclude that herbivore disturbance, and not soil nutrients, provide C. dactylon with a competitive advantage over H. hirta, due to vegetative regeneration from its rhizomes. This provides evidence for the importance of concentrated, high herbivore densities for the creation and maintenance of grazing lawns.