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Restoration of many grassland ecosystems is dependent on restoring native N cycling regimes, through methods such as nutrient stripping, C addition, and/or re-establishment of keystone species. We studied topsoil N pools and fluxes under five different understorey vegetation communities of different degradation states of grassy eucalypt woodlands across 11 sites in New South Wales, Australia, in order to identify whether high N flux but low standing N concentrations were responsible for the success of reference Themeda triandra communities. The presence of NO3− was the main differentiator between the annual exotic (AE) and reference states, which both demonstrated twofold-threefold increases N flux relative to the depleted states. Reference states were characterised by high proteolysis and dissolved organic N (DON) mineralisation rates, but also low δ15N and a high C:N ratio, which taken together indicate fresh organic matter inputs that turn over quickly. In quantifying fast rates of N cycling yet low NO3− pools in the reference states, our data highlight a productive ecosystem dominated by rapidly cycling DON rather than NO3− in its reference state. The higher NO3− concentrations coupled with fast N cycling in the degraded AE state indicate that although available N production is high in both systems, uptake is lower in the AE state, perpetuating a larger standing NO3− pool that may prevent re-establishment of native species. Steps that promote rapid DON cycling while inhibiting nitrification may lead to a soil biogeochemical status more suitable for the restoration of highly productive native grasslands.

Themeda triandra Forssk. — Habit: Herb. Habitat: LMDF; up to 3 200 m. Distribution: I. Voucher: Mutamayu Farm on Burguret River, Alt. 1 950 m, 29 Dec. 1999, Robertson 7307 (EA). References: Fries & Fries (1929), Young & Young (1983), Bussmann (1993, 1994)., Published as part of Zhou, Ya-Dong, Mwachala, Geoffrey, Hu, Guang-Wan & Wang, Qing-Feng, 2022, Annotated checklist of the vascular plants of Mount Kenya, East Africa, pp. 1-108 in Phytotaxa 546 (1) on page 40, DOI: 10.11646/phytotaxa.546.1.1, http://zenodo.org/record/6550464, {"references":["Fries, R. E. & Fries, T. C. E. (1929) Beitrage zur Kenntnis der Flora des Kenia, Mt. Aberdare und Mt. Elgon. XII. Notizblatt des Koniglichen Botanischen Gartens und Museums zu Berlin 10 (96): 594 - 621. https: // doi. org / 10.2307 / 3994784","Young, H. J. & Young, T. P. (1983) Local distribution of C 3 and C 4 grasses on Mount Kenya. Oecologia 58: 373 - 377. https: // doi. org / 10.1007 / BF 00385238","Bussmann, R. W. (1993) The forest of Mt. Kenya (Kenya): A phytosociological approach with special reference to ecological problems. Ph. D. Thesis, Eberhard Karls Universitat Tubingen, Tubingen, 119 pp.","Bussmann, R. W. (1994) The forest of Mt. Kenya (Kenya): Vegetation, ecology, destruction and management of a tropical mountain forest ecosystem. Ph. D. dissertation, Universitat Bayreuth Startseite, Bayreuth, 252 pp."]}

Global climate change poses a significant threat to natural communities around the world, with many plant species showing signs of climate stress. Grassland ecosystems are not an exception, with climate change compounding contemporary pressures such as habitat loss and fragmentation. In this study, we assess the climate resilience of Themeda triandra, a foundational species and the most widespread plant in Australia, by assessing the relative contributions of spatial, environmental and ploidy factors to contemporary genomic variation. Reduced-representation genome sequencing on 472 samples from 52 locations was used to test how the distribution of genomic variation, including ploidy polymorphism, supports adaptation to hotter and drier climates. We explicitly quantified isolation by distance (IBD) and isolation by environment (IBE) and predicted genomic vulnerability of populations to future climates based on expected deviation from current genomic composition. We found that a majority (54%) of genomic variation could be attributed to IBD, while an additional 22% (27% when including ploidy information) could be explained by two temperature and two precipitation climate variables demonstrating IBE. Ploidy polymorphisms were common within populations (31/52 populations), indicating that ploidy mixing is characteristic of T. triandra populations. Genomic vulnerabilities were found to be heterogeneously distributed throughout the landscape, and our analysis suggested that ploidy polymorphism, along with other factors linked to polyploidy, reduced vulnerability to future climates by 60% (0.25-0.10). Our data suggests that polyploidy may facilitate adaptation to hotter climates and highlight the importance of incorporating ploidy in adaptive management strategies to promote the resilience of this and other foundation species.

Land degradation is a global problem leading to a diminished production capacity of the rangelands. The consequence is reduced potential to provide ecosystem services and increased vulnerability to the inhabitants. Biological soil water conservation measures can reverse the trend. Different communities prefer different grass species for rehabilitation as communities vary in location, needs, priorities, preferences and the type of livestock reared. This study, therefore, sought to identify the suitable grass species for soil erosion and rehabilitation from the community in Keekonyoie ward In Narok county, Kenya. Data collection was through individual interviews, focus groups, key informant interviews and field observations. Results showed that level, indicators, causes and impacts are known to the community. Cynodon plectostachyus (76%), Chloris gayana (73%), Pennisetum clandestinum (69%), Cymbopogon citratus (46%) and Themeda triandra (42%) were most preferred for rehabilitation and soil erosion control. The primary reason for the grasses choice was a yearlong provision of livestock feed. Needs and livelihood priorities significantly influence decision-making among the Maa-speaking community in Keekonyoie ward. We recommend consideration of community needs, priorities and preferences in the selection of grass species for rehabilitation to increase the adoption measures that can reverse land degradation Key words: Indigenous knowledge, community perceptions, range grass species, rehabilitation, land degradation, Narok.

This study was conducted in Adami-Tullu Jido-Kombolcha and Arsi Negelle districts, south central Ethiopia. The objectives of the study were to evaluate the interactive effects of grazing management systems and rangeland sites on dry-matter production and chemical composition of herbaceous plants in south central Ethiopia. Data were analyzed using GLM procedure in SPSS 16.0 version, which was used for mean comparisons using post-hoc t-test that can be employed to compare mean differences for enclosure and open-grazed areas. To test the effects of management systems and altitudinal variation on dry-matter production and chemical composition of herbaceous species, mixed model analysis was employed using sample site as a random variable while grazing management systems and altitude were fixed variables. A total of 28 herbaceous species were identified. Of the identified herbaceous species, 20 species were grasses, 2 species were legumes while 6 species were forbs. Among the recorded grass species, some were highly desirable, while others were in the categories of intermediate in terms of desirability and less desirable. We identified the dominant and common grass species that included: Arstida adscensionis, Cenchrus ciliarus, Chloris gayana, Chloris roxburghiana, Bothriochloa insculpta, Eragrostis papposa, Heteropogon contorus, Panicum maximum, Indigofer spinosa, Tephrosia pumila, Sporobolus pyrmidalis, Themeda triandra, B. nigropedata, Ocimum basilicum, Amaranthus dubis, Tribulos terrestris and Achyrantes aspera. The chemical composition of herbaceous plants were analyzed for DM, CP, NDF, ADF, ADL and Ash comparing two grazing management systems and three rangeland sites as patch mosaic units. The results of the present analysis showed that the average CP content in the open-grazed areas was significantly (P

Our study investigated the effects of fire frequency on the tree and grass components of Cumberland Plain Woodland, an endangered grassy eucalypt woodland in eastern Australia. We located three sites within each of three fire frequency classes (high, moderate, low) based on fire history and a similar time since last fire. For trees, we asked whether fire frequency affected density, eucalypt population structure, basal area and spatial patterning. For grasses, we tested for fire frequency effects on total abundance and the abundance of two common species. Density of trees was not significantly affected by fire frequency for juveniles, saplings or adult trees and neither was basal area per hectare. Features of a recruitment bottleneck model were present for eucalypts. There was a large pool of suppressed juveniles making up more than half the population at each fire frequency. Saplings were the smallest group and were susceptible to fire‐induced stem mortality, with particularly low numbers relative to juveniles and small trees where fire was frequent or intense. Despite this difference in sapling mortality, numbers of small trees did not differ with fire frequency. Saplings could transition to small trees in equal numbers if they did so more quickly at high than at lower fire frequencies, and if recruitment of saplings into the tree layer was controlled independently of fire frequency. The size hierarchy of small to medium eucalypt trees was homogeneous over eight of the nine sites, spatial patterning of adult trees was random tending to regular, and mean tree size decreased with density at all sites. These features of eucalypt population structure are indicative of possible resource competition which could regulate tree recruitment. Total grass cover index was high across all fire frequencies, with Themeda triandra dominating at high and moderate fire frequencies and Microlaena stipoides at low fire frequency.

A comparative survey was done of the spider assemblages found in grass tussocks of three grass species (Cymbopogon pospischilii, Eragrostis lehmanniana and Themeda triandra) occurring in three diff...

QUESTIONS: The recovery of dominant tussock grasses following fire is crucial as they contribute disproportionately to the structure and function of grasslands. To determine how resilient native grasslands are to the re‐introduction of fire, we quantify how fire affects the resprouting of the dominant C₃ tussock grasses in long‐unburned grasslands (Austrostipa spp.) and compare this to the recovery of C₄ tussock grasses (Themeda triandra) in grasslands that have had regular exposure to fire. We also quantify if these two grassland types burn in different ways as a result of their different dominant grass compositions. LOCATION: Temperate native tussock grasslands on the Victorian volcanic plain, Australia. METHODS: To determine how fire affects tussock mortality, and whether this differs between C₄ (regularly) and C₃ (long‐unburned) grasslands, tussocks were permanently marked pre‐fire and re‐censused for survival and growth at seven weeks after fire. To assess whether C₃ grasslands burn in a different way to C₄ grasslands, fire behaviour was quantified at 11 sites. RESULTS: Fire behaviour was similar in both grassland types. Both C₃ and C₄ grass tussocks were resilient to fire, despite decades of fire suppression in C₃ grasslands. Tussock mortality was low (

Here we assessed N and P uptake of four grassland species grown together in response to a short-term drought event along a soil P gradient. We used 15N and 32P tracers to examine uptake of N and P by the grasses Bothriochloa macra, Themeda triandra, Lolium perenne and Microlaena stipoides grown together in pots with initial available P levels of 3, 8, 12, 20 mg P kg−1 soil. Soil moisture in half the pots was reduced from 60 to 30% water holding capacity during a 7-day period to simulate drought. Plant P uptake was strongly reduced by drought in all species across all P levels, much more so than N uptake, indicating decoupling in N and P uptake. Soil available P (Bray method) was not affected by drought, suggesting that the reduced P uptake with drought was due to reduced soil P mobility. Plant competition for N and P changed with drought and soil P levels, where relatively more N and P was taken up with drought by M. stipoides at the lowest soil P level. We showed that greater reductions in P than in N uptake and shifts in N and P uptake among species caused by a short-term drought have strong consequences for plant growth.

Ecotypes are distinct populations within a species which are adapted to specific environmental conditions. Understanding how these ecotypes become established, and how they interact when reunited, is fundamental to elucidating how ecological adaptations are maintained. This study focuses on Themeda triandra, a dominant grassland species across Asia, Africa and Australia. It is the most widespread plant in Australia, where it has distinct ecotypes that are usually restricted to either wetter and cooler coastal regions or the drier and hotter interior. We use whole genome sequencing for over 80 Themeda accessions to reconstruct the evolutionary history of T. triandra and related taxa. A chloroplast phylogeny confirms that Australia was colonised by T. triandra twice, with the division between ecotypes predating their arrival in Australia. The nuclear genome provides evidence of gene-flow among the ecotypes, largely restricted to two geographic areas. In northern Queensland there appears to be a hybrid zone with admixed nuclear genomes and shared plastid haplotypes. Conversely, in the cracking claypans of Western Australia, there is cytonuclear discordance with individuals possessing the coastal plastid and interior clade nuclear genomes. This chloroplast capture is potentially a result of adaptive introgression, with selection detected in the rpoC2 gene which is associated with water use efficiency. A stable hybrid zone in the east, and the displacement of one ecotype in the west, highlights the unpredictable nature of hybrid zones, with repeated contacts between the same ecotypes producing different outcomes.

Water sources in arid and semiarid ecosystems support humans, wildlife, and domestic animals, forming nodes of activity that sculpt surrounding plant communities and impact critical grazing and soil systems. However, global aridification and changing surface water supply threaten to disrupt these water resources, with strong implications for conservation and management of these ecosystems. To understand how effects of herbivore aggregation at water impact plant communities across contexts, we measured herbivore activity, plant height, cover (trees, grasses, forbs, and bare ground), diversity, and composition at 17 paired water sources and matrix sites across a range of abiotic factors in a semiarid savanna in Kenya. The effects of proximity to surface water and herbivore aggregation on plant communities varied substantially depending on soil and rainfall. In arid areas with nutrient-poor sandy soils, forb and tree cover were 50% lower at water sources compared to neighboring matrix sites, bare ground was 20% higher, species richness was 15% lower, and a single globally important grazing grass (Cynodon dactylon) dominated 60% of transects. However, in mesic areas with nutrient-rich finely textured soils, species richness was 25% higher, despite a 40% increase in bare ground, concurrent with the decline of a dominant tall grass (Themeda triandra) and increase in C. dactylon and other grass species near water sources. Recent rainfall was important for grasses; cover was higher relative to matrix sites only during wet periods, a potential indication of compensatory grazing. These findings suggest that effects of herbivore aggregation on vegetation diversity and composition will vary in magnitude, and in some cases direction, depending on other factors at the site. Where moisture and nutrient resources are high and promote the dominance of few plant species, herbivore aggregations may maintain diversity by promoting grazing lawns and increasing nondominant species cover. However, in arid conditions and sites with low nutrient availability, diversity can be substantially reduced by these aggregations. Our results highlight the importance of considering abiotic conditions when managing for effects of herbivore aggregations near water. This will be particularly important for future managers in light of growing global aridification and surface water changes.

Parthenium hysterophorus L. is among one of the most problematic invasive grassland weeds in Australia, and in many other countries around the world. It can reduce pasture and livestock production, natural community biodiversity, and negatively affect human and animal health. Sowing of selected suppressive pasture plants in parthenium weed infested grasslands has shown potential to improve efficacy of management. However, such species need to be tested for their ability to suppress weed growth under grazing conditions. The parthenium weed suppressive and fodder production capacity of six selected pasture species [purple pigeon grass (Setaria incrassata), buffel grass (Cenchrus ciliaris), butterfly pea (Clitoria ternatea), Kangaroo grass (Themeda triandra), bull Mitchell grass (Astrebla squarrosa) and Indian bluegrass (Bothriochloa pertusa)] was tested under no (0%), low (25%), moderate (50%) and heavy (75%) simulated grazing pressures in a grassland area of south-central Queensland, Australia. Purple pigeon grass, buffel grass and butterfly pea legume suppressed the growth of parthenium weed by >50% under low and moderate simulated grazing pressures, as well as generating moderate to high amounts of fodder biomass (up to 5.07 t ha per year). Native species, Kangaroo grass and bull Mitchell grass both suppressed the parthenium weed's growth by >50% under low simulated grazing pressure, however, they generated low to moderate amounts of biomass, 1.83 t ha and 2.7 t ha per year, respectively. The sowing of selected suppressive pasture species in parthenium weed infested grasslands with low-to-moderate grazing pressure, assuming this corresponds closely with the simulated treatment, would provide an additional tool to the best practice weed management strategy as well as sustaining fodder production.

Shrub invasion is a recent occurrence in African grassland ecosystems. This study assessed the distribution of Euryops floribundus (a native shrub species) along an elevation and invasion intensity gradients, and its relationship with soil and herbaceous vegetation in a South African grassland. Shrub density increased (p

The local ecological knowledge (LEK) and perceptions of grasses were investigated in six semi-arid communal areas in the central Eastern Cape province, South Africa, and compared with field studies and scientific knowledge. Of the total of 21 grasses identified in the field survey, communal farmers had vernacular names only for 11 species. Respondents rated Digitaria eriantha and Pennisetum clandestinum to have the highest (p < 0.05) grazing value. Respondents’ ratings of Eragrostis obtusa and Sporobolus africanus as having similar (moderate) grazing values to Themeda triandra is against the established knowledge. Respondents’ ratings of T. triandra and S. africanus as having higher (p = 0.01) ecological value than the other grasses concur with the scientific knowledge, whereas their nomination of E. obtusa and D. eriantha as providing less ecological benefits than Aristida conjesta disagrees with some ecologists. The study hinted at the complementarity and discrepancies between LEK and scientific knowledge that need ratification. The respondents’ lack of detailed knowledge is suggestive of a gradual eroding of LEK among the local communities that will adversely impact the local people’s ability to implement sustainable rangeland utilisation practice. The current study also recognised farmers’ familiarity as well as training needs that would expound their knowledge and management of grasses.Keywords: communal grazing, ecological value, forage production, grazing value, semi-arid

There is little experimental evidence to guide the design of substrate compaction for the optimal plant water use performance of a landfill phytocap. A glasshouse study was undertaken to address this with aim to evaluate the effect of substrate compaction on the water use of a phytocap plant community. Four levels of relative compaction (RC), i.e. the ratio of dry bulk density over the standard maximum dry bulk density, (72%, 77%, 82%, and 87%) were considered. The native tree and grass species selected were typical of an Australian phytocap plant community: Themeda triandra, Microlaena stipoides, Eucalyptus camaldulensis, Eucalyptus cladocalyx, Acacia mearnsii and Allocasuarina verticillata. Plant water use was measured by weight as the difference between planted and unplanted cores over 5 drying periods occurring through the first 6 months of plant establishment traversing winter, spring and summer. Plant water use was optimal for all species at low-intermediate RC (72%, 77% and 82%), and all species except Themeda triandra, were most negatively impacted by the highest RC of 87%. The best linear model based on Akaike’s Information Criterion included a second-order term for the continuous fixed factor ‘RC’ and the categorical fixed factor ‘species’. This model showed plant water use to be optimum at a RC of 76.5% and highlighted a wide range of RC’s (70–83%), for which plant water use is not 86% and a RC

Themeda triandra Forssk., Fl. Aegypt.-Arab.: 178 (1775). Distribution: Africa, Trop. & Subtrop. Asia to Australia Specimens: MOSHI Engare Nairobi, Greenway, P.J. 6700 (K, NH); Engare Nairobi, Moss, M. 13 (K); Holili, Hemp, A. 1868 (NHT, UBT); Lake Chala, Hemp, A. 680 (UBT); Lolorai Hill, Grimshaw, J.M. 931213 (K); Marangu, Schlieben, H.J. 4705 (K, NH); Marangu, Volkens, G. 1481 (E, K); Moshi, Haarer, A.E. 755 (K); Moshi, Hitchcock, A.S. 24583 (K); Moshi, Shantz, H.L. 789 (K); s. loc., Endlich, R. 32 (NH); s. loc., Milne, G. 13 (NH); s. loc., Schlieben, H.J. 4705B (NH); s. loc., Volkens, G. 303 (K); Simba Farm, Bigger, M. 2356 (K)., Published as part of Prunera-Olivé, Joan, Vorontsova, Maria S., Williams, Emma V., Mollel, Neduvoto P. & Hemp, Andreas, 2021, Checklist of Kilimanjaro grasses shows that both plot and herbarium methods are necessary to record diversity, pp. 201-244 in Phytotaxa 501 (2) on page 242, DOI: 10.11646/phytotaxa.501.2.1, http://zenodo.org/record/5424816

The aim of this thesis was to investigate the linkages between changes in habitat structure in Brisbane Forest Park and the distribution of macropod populations, particularly eastern grey kangaroo, the red necked wallaby, the whiptail wallaby and macropod species richness. The whiptail wallaby has been reported to have declined and possibly experienced local extinction in Brisbane Forest Park in recent decades. A key hypothesis of this thesis was that the reason for whiptail wallaby declines is alteration of the habitat structure and grass composition due to declines in the frequency of controlled burning. Multi-temporal analysis of aerial photographs shows that habitat structure of Brisbane Forest Park has become increasingly dominated by tree cover. Outcomes of interpretation of tree cover in aerial photographs reveal evidence of an increase in tree and shrub cover over the last 50 years in Brisbane Forest Park and the neighbouring Samford Valley, with a small increase in the Wivenhoe Dam area where whiptail wallabies were observed to be present. Changes in the incidence of fire during the last 30 years may also have had impacts on growth of grasses supporting wallaby presence. Using analysis of regression models, hierarchical partitioning analysis, analysis of variance and chi-squared analyses for eastern grey kangaroos showed grazing, tree cover, grass height, elevation and slope were important in that order. For the red-necked wallaby, tree cover, grazing, grass height, shrub cover, slope and elevation were most important in that order. For macropod species richness, grazing, tree cover, grass height, shrub cover, slope and elevation were most important in that order. The whiptail wallaby was only present at the Wivenhoe study area, with fire within the previous 6 months, grazing (especially by cattle), an open shrub and tree cover, short (

Themeda and Heteropogon are closely related grass genera frequently dominant in tropical C4 grasslands. Relationships between them are poorly resolved, impeding ecological study, especially of T. triandra with a broad distribution from Africa to East Asia, and H. contortus with a pantropical distribution. Our analyses of plastome and nuclear genomes with comprehensive sampling of Themeda and Heteropogon demonstrate that neither genus is monophyletic as currently circumscribed. Plastome and nuclear data place H. melanocarpus and H. ritchiei in Themeda. Nested in T. triandra are T. quadrivalvis and T. unica, demonstrating that this widespread species is more morphologically diverse than previously recognized. Heteropogon fischerianus is nested in H. contortus. The picture is more complex for H. triticeus that is sister to H. contortus in the nuclear analysis and to Cymbopogon in the plastome analysis. This incongruence between nuclear and plastid phylogenetic trees suggests hybridization between Cymbopogon-related genome donors and H. contortus. Plastome dating estimates the Themeda–Heteropogon crown age at c. 7.6 Myr, consistent with the Miocene C4 grassland expansion. Themeda triandra and H. contortus diversified 1–2 Mya in the Pleistocene. These results establish a foundation for studying the history of these ecologically significant widespread grasses and the ecosystems they form.

1. SITE DESCRIPTIONThe Cathedral Peak research catchments, which form part of a strategic water source area for South Africa, consist of ten (named I – X) well defined hydrological catchments, ranging in altitude from 1 820 m.a.s.l to 2 463 m.a.s.l (Figure 1). The catchments fall within the summer rainfall region of South Africa, experiencing wet, humid summers and cold, dry winters (Everson et al ., 1998). The mean annual precipitation (MAP) for the area is approximately 1 400 mm (Bosch, 1979), with 84 % of this rainfall occurring between the months of October and March (Schulze, 1976). Half of the rainfall events in the catchments are thunderstorms (Schulze, 1976). Approximately 49 % of the rainfall is converted to streamflow, with two thirds of the streamflow yield occurring during the four months from January to April (Bosch, 1979). The natural vegetation of the catchments is fire-adapted montane grassland, dominated by the grass (Themeda triandra) . Woody communities dominated by Leucosidea sericea and Buddleia salvifolia occur in narrow, fire-protected zones along the streams in some catchments (Bosch, 1979).

The annual herb Parthenium hysterophorus L. (Asteraceae), remains one of Southern Africa's most significant invasive weeds, commonly invading savannas, and their rangelands, causing severe losses to agriculture, livestock production and native biodiversity. Previous studies have suggested that perennial grasses may act as useful competitive species, capable of suppressing the growth and invasion of P. hysterophorus. To explore this, a total of 48 plots were established within an invaded savanna, using a randomised block design, and included treatments with and without the clearing of P. hysterophorus, as well as with and without the sowing of native perennial grass seed (Anthephora pubescens, Chloris gayana, Cynodon dactylon, Digitaria eriantha, Eragrostis curvula, Panicum maximum and Themeda triandra). Plots were assessed yearly in terms of P. hysterophorus density and growth as well as grass species composition, basal cover, and biomass over a three-year period. Clearing alone was found to exacerbate invasion, increasing P. hysterophorus density by 40%. Whereas the sowing of grass seed, in both the cleared and uncleared plots, increased the abundance of perennial grass species by 28%, subsequently reducing the size, reproductive output and density of P. hysterophorus over the three years. In addition, these sowing efforts contributed towards partial restoration of the plots, enhancing grass basal cover by ~15% and biomass production by 17%. Overall, this research suggests that sowing of native grass species, with or without clearing, may be a useful supplementary control or restoration tool towards the long-term management of P. hysterophorus invasions in managed savannas and rangelands in Southern Africa.

SummaryFragmented grassland ecosystems, and the species that shape them, are under immense pressure. Restoration and management strategies should include genetic diversity and adaptive capacity to improve success but these data are generally unavailable. Therefore, we use the foundational grass,Themeda triandra, to test how spatial, environmental, and ploidy factors shape patterns of genetic variation.We used reduced-representation genome sequencing on 487 samples from 52 locations to answer fundamental questions about how the distribution of genomic diversity and ploidy polymorphism supports adaptation to harsher climates. We explicitly quantified isolation-by-distance (IBD), isolation-by-environment (IBE), and predicted population genomic vulnerability in 2070.We found that a majority (54%) of the genomic variation could be attributed to IBD, while 22% of the genomic variation could be explained by four climate variables showing IBE. Results indicate that heterogeneous patterns of vulnerability across populations are due to genetic variation, multiple climate factors, and ploidy polymorphism, which lessened genomic vulnerability in the most susceptible populations.These results indicate that restoration and management ofT. triandrashould incorporate knowledge of genomic diversity and ploidy polymorphisms to increase the likelihood of population persistence and restoration success in areas that will become hotter and more arid.

This paper presents a random forest classification approach for identifying and mapping three types of lowland native grassland communities found in the Tasmanian Midlands region. Due to the high conservation priority assigned to these communities, there has been an increasing need to identify appropriate datasets that can be used to derive accurate and frequently updateable maps of community extent. Therefore, this paper proposes a method employing repeat classification and statistical significance testing as a means of identifying the most appropriate dataset for mapping these communities. Two datasets were acquired and analysed; a Landsat ETM+ scene, and a WorldView-2 scene, both from 2010. Training and validation data were randomly subset using a k-fold (k = 50) approach from a pre-existing field dataset. Poa labillardierei, Themeda triandra and lowland native grassland complex communities were identified in addition to dry woodland and agriculture. For each subset of randomly allocated points, a random forest model was trained based on each dataset, and then used to classify the corresponding imagery. Validation was performed using the reciprocal points from the independent subset that had not been used to train the model. Final training and classification accuracies were reported as per class means for each satellite dataset. Analysis of Variance (ANOVA) was undertaken to determine whether classification accuracy differed between the two datasets, as well as between classifications. Results showed mean class accuracies between 54% and 87%. Class accuracy only differed significantly between datasets for the dry woodland and Themeda grassland classes, with the WorldView-2 dataset showing higher mean classification accuracies. The results of this study indicate that remote sensing is a viable method for the identification of lowland native grassland communities in the Tasmanian Midlands, and that repeat classification and statistical significant testing can be used to identify optimal datasets for vegetation community mapping.

The functional relationship between arbuscular mycorrhizal fungi (AMF) and their hosts is variable on small spatial scales. Here, we hypothesized that herbivore exclusion changes the AMF community and alters the ability of AMF to enhance plant tolerance to grazing. We grew the perennial bunchgrass, Themeda triandra Forssk in inoculum from soils collected in the Kenya Long-term Exclosure Experiment where treatments representing different levels of herbivory have been in place since 1995. We assessed AMF diversity in the field, using terminal restriction fragment length polymorphism and compared fungal diversity among treatments. We conducted clipping experiments in the greenhouse and field and assessed regrowth. Plants inoculated with AMF from areas accessed by wild herbivores and cattle had greater biomass than non-inoculated controls, while plants inoculated with AMF from where large herbivores were excluded did not benefit from AMF in terms of biomass production. However, only the inoculation with AMF from areas with wild herbivores and no cattle had a positive effect on regrowth, relative to clipped plants grown without AMF. Similarly, in the field, regrowth of plants after clipping in areas with only native herbivores was higher than other treatments. Functional differences in AMF were evident despite little difference in AMF species richness or community composition. Our findings suggest that differences in large herbivore communities over nearly two decades has resulted in localized, functional changes in AMF communities. Our results add to the accumulating evidence that mycorrhizae are locally adapted and that functional differences can evolve within small geographical areas.

Shrub encroachment is an issue worldwide with consequences which may have both positive and negative outcomes for landscape and community health. Themeda-dominated communities on headlands are listed as endangered within New South Wales, Australia with shrub encroachment listed as threat. Coastal headlands are considered harsh environments and positive effects on species diversity patterns may occur due to variables that ameliorate these conditions or through indirect mechanisms. Shrubs are a natural component of coastal headlands in eastern Australian and tall shrub encroachment may have both positive and negative effects on non-shrub communities. I test whether tall shrubs may have a functional role that positively affects species diversity within and between plots and the distribution of species within Themeda-dominated communities on headlands. 352 2 × 2 m plots were placed on 46 headlands along a 530 km stretch of coastline on the North Coast Bioregion, New South Wales, Australia. Within plots vascular plant species were scored on cover and frequency. Species density, diversity, evenness, turnover and gamma diversity were calculated. Variables tested include cumulative tall shrub height from circular transects at 2, 4 and 8 m from plots, slope, aspect, altitude, ground layer height, distance to closest seaward edge and macropod grazing intensity. Rarefaction was performed on a subset of sites that had no shrubs and sites within shrubs within 8 m of plots. The relative interaction intensity (RII) was calculated for all taxa with more than one observation against plots without shrubs and plots with shrubs within 8 m radius. Analyses were performed using Canonical Correspondence Analysis (CCA) and Generalised Additive Modelling (GAM) on species frequency data. A total of 303 native taxa were recorded within plots. The most significant positive effects on species density, evenness and species accumulation included increasing proximity to, and density of tall shrubs. Tall shrubs may allow direct facilitation of less stress tolerant plants to colonise but may have an indirect interaction by reduction in the dominance of Themeda triandra. Other minor significant variables included distance from headland seaward edge, southern and western facing slopes, higher altitudes and a decrease in ground layer height. 178 (80%) of species were found to have a positive RII score associated with the presence of nearby taller shrubs. Tall shrubs may directly facilitate greater species diversity by ameliorating local conditions and indirectly facilitate by reducing the over-dominance of some taxa. In spite of the positive effect of shrubs on diversity eventually tall shrub encroachment may cause replacement of the Themeda-dominated communities with shrubland. Encroaching taller shrubs are therefore shown to be both of benefit to floristic species diversity at all scales within these Themeda-dominated communities on headlands in eastern Australia but also a potential threat. These results highlight the complex nature of community interactions requiring nuanced and potentially novel approaches to management.

Understanding fire regimes in the coastal region of the Pondoland center of plant endemism, (Eastern Cape, South Africa) is of critical importance, especially in areas where anthropogenic ignitions influence the fire regime. We characterized the fire regime (2007 to 2016) of Mkambati Nature Reserve (9200 ha) in terms of fire season, seasonality of fire-prone weather conditions, fire return interval (FRI), and influence of poaching-related ignitions. Fires were concentrated in winter when monthly fire danger weather index was highest. The mean FRI at Mkambati was

Grasses are an important part of the forage of many herbivorous mammals and their phytoliths have long been regarded as the most important agent of tooth wear. Recent work has challenged this “paradigm” in finding evidence 1. of native phytoliths to be much softer then tooth enamel and 2. indicating, that phytolith hardness is highly variable, 3. prone to methodology and 4. not easy to be related to habitat conditions. We conduct controlled silica-cultivations measuring SiO2 content in the common forage grass Themeda triandra. Phytoliths are extracted natively, and nano-indentation values are measured. Phytolith hardness in Themeda triandra is found to be independent of silicate availability in the substrate. We further investigate the phytolith ultrastructure of Hordeum vulgare phytoliths. Phytoliths are shown to be an anisotropic composite of at least 3 components, silica bodies, inter-body matrix (both mineralised) and globular inclusions (likely non-mineralised). It can be argued, that indentation will be largely influenced by the heterogeneity of the structure and thus nano-indentation measurements will largely reflect the matrix and its mechanical properties but not necessarily the silicate bodies, which make up the vast majority of a phytolith.

The present study assessed the potential of varying spectral configuration of Landsat 8 Operational Land Imager (OLI), Sentinel 2 MultiSpectal Instrument (MSI) and Worldview 2 sensors in the seasonal discrimination of Festuca costata (C3) and Themeda Triandra (C4) grass species in the Drakensberg, South Africa. This was achieved by resampling hyperspectral measurements to the spectral windows corresponding to the three sensors at two distinct seasonal periods (summer peak and end of winter), using the Discriminant Analysis (DA) classification ensemble. In summer, standard bands of the Worldview 2 produced the highest overall classification accuracy (98.61%), followed by Sentinel 2 (97.52%), whereas the Landsat 8 spectral configuration was the least performer, using vegetation indices (95.83%). In winter, Sentinel 2 spectral bands produced the highest accuracy (96.18%) for the two species, followed by Worldview 2 (94.44%) and Landsat 8 yielded the least (91.67%) accuracy. Results also showed that maximum separability between C3 and C4 grasses was in summer, while at the end of winter considerable overlaps were noted, especially when using the spectral settings of the Landsat 8 OLI and Sentinel 2 shortwave infrared bands. Test of significance in species reflectance further confirmed that in summer, there were significant differences (P 0.05) between the two species. In this regard, the peak summer period presents a promising opportunity for the spectral discrimination of C3 and C4 grass species functional types, than the end of winter, when using multispectral sensors. Results from this study highlight the influence of seasonality on discrimination and therefore provide the basis for the successful discrimination and mapping of C3 and C4 grass species.