scholarly journals Field-Deployed Extruded Seed Pellets Show Promise for Perennial Grass Establishment in Arid Zone Mine Rehabilitation

2020 ◽  
Vol 8 ◽  
Author(s):  
Emma Stock ◽  
Rachel J. Standish ◽  
Miriam Muñoz-Rojas ◽  
Richard W. Bell ◽  
Todd E. Erickson
Keyword(s):  
Organic Amendment ◽  
Arid Zone ◽  
Mine Waste ◽  
Seedling Emergence ◽  
Perennial Grass ◽  
Rainfall Regime ◽  
Native Plant ◽  
Mine Rehabilitation ◽  
Trade Offs ◽  
Soil Mixtures

Current methods of mine rehabilitation in the arid zone have a high failure rate at seedling emergence largely due to limited availability of topsoil and low water-holding capacity of alternative growth substrates such as mining overburden and tailings. Further, seedlings have consistently failed to emerge from seeds sown on the soil surface using traditional broadcasting methods. Seed pellets, formed by extruding soil mixtures and seeds into pellets, can potentially increase soil water uptake through enhanced soil-seed contact and thereby improve seedling emergence. We tested an extruded seed pelleting method in a three-factor field experiment (i.e., different pellet-soil mixtures, organic amendments, and simulated rainfall regimes) in north-western Australia. Given the observed lack of seedling emergence from broadcast seeds, the aims of the experiment were to assess: (i) the use of pellets to promote native seedling emergence and establishment and; (ii) the soil physico-chemical and microbiological changes that occur with this method of rehabilitation. The effects of pellet-soil mixtures, organic amendment, and rainfall regime on seedling emergence and survival of three native plant species suggest trade-offs among responses. Pellets made with a 1:1 blend of topsoil and a loamy-sand waste material had the highest seedling emergence, while 100% topsoil pellets had lower emergence probably because of hardsetting. Triodia pungens (a native grass) survived to the end of the experiment while Indigofera monophylla and Acacia inaequilatera (native shrubs) emerged but did not survive. Adding an organic amendment in the extruded pellet inhibited Triodia seedling emergence but increased soil microbial activity. Overall, extruded pellets made from a 1:1 blend showed promise for the establishment of Triodia seeds and beneficially, incorporates mine waste overburden and lesser amounts of topsoil. Further research is needed to improve pelleting production and to test the applicability of the method at scale, for different species and other ecosystem types.

Benefits of adopting seed-based technologies for rehabilitation in the mining sector: a Pilbara perspective

2017 ◽  
Vol 65 (8) ◽  
pp. 646 ◽  
Author(s):  
Todd E. Erickson ◽  
Miriam Muñoz-Rojas ◽  
Olga A. Kildisheva ◽  
Brad A. Stokes ◽  
Stephen A. White ◽  
...  
Keyword(s):  
Western Australia ◽  
Large Scale ◽  
Iron Ore ◽  
Seedling Emergence ◽  
Growth Media ◽  
Native Plant ◽  
Media Management ◽  
North West ◽  
Seed Collection ◽  
Mine Rehabilitation

The use of native plant seeds is fundamental to large-scale rehabilitation and the re-establishment of self-sustaining ecosystems after high-impact mining activity has ceased. However, many of the biological attributes of seeds are often overlooked in large-scale rehabilitation programs. Multi-disciplinary, long-term research collaborations are required to improve seed-based mine rehabilitation. In this paper, we review the steps that BHP Western Australia Iron Ore (WAIO), a large iron ore mining company that operates in the Pilbara bioregion of north-west Western Australia, has taken over the past 9 years to ensure continuous improvement in rehabilitation procedures. We introduce the mining activities that WAIO undertake in the Pilbara, and emphasise specific examples of how research findings have led to incremental improvements in the seed management cycle, growth media management and mine rehabilitation practices. Specifically, we outline how the implementation of structured seed collection and storage programs has created the capacity to maintain high-quality seed stocks sufficient for 3–5 years of future rehabilitation. Research has documented the prevalence of seed dormancy in the flora (>70% of 105 species examined produce dormant seeds), with physical and physiological classes of dormancy most commonly encountered. We discuss the development of seed-treatments such as optimised wet-heat and dry after-ripening that have increased the germination capacity of many previously dormant seed batches. In addition, we highlight how seed enhancement technologies, such as hydro-priming with smoke-derived germination stimulants and polymer seed coating, and a greater understanding of the biological and physical limitations present in the growing environment, have vastly improved seedling emergence performance under field conditions for key framework Triodia species. Ongoing industry support (e.g. construction of a purpose-built rain manipulation shelter) has ensured research in the Pilbara will continue to unpack and resolve the complex challenges associated with seed regeneration of biodiverse native plant communities after mining.

No bush foods without people: the essential human dimension to the sustainability of trade in native plant products from desert Australia

2011 ◽  
Vol 33 (4) ◽  
pp. 395 ◽  
Author(s):  
Fiona Walsh ◽  
Josie Douglas
Keyword(s):  
Research And Development ◽  
Reference Group ◽  
Rainfall Variability ◽  
Forest Products ◽  
Annual Rainfall ◽  
Ecological Sustainability ◽  
Small Scale ◽  
Native Plant ◽  
Plant Products ◽  
Trade Offs

Improvement in Aboriginal people’s livelihoods and economic opportunities has been a major aim of increased research and development on bush foods over the past decade. But worldwide the development of trade in non-timber forest products from natural populations has raised questions about the ecological sustainability of harvest. Trade-offs and tensions between commercialisation and cultural values have also been found. We investigated the sustainability of the small-scale commercial harvest and trade in native plant products sourced from central Australian rangelands (including Solanum centrale J.M. Black, Acacia Mill. spp.). We used semi-structured interviews with traders and Aboriginal harvesters, participant observation of trading and harvesting trips, and analysis of species and trader records. An expert Aboriginal reference group guided the project. We found no evidence of either taxa being vulnerable to over-harvest. S. centrale production is enhanced by harvesting when it co-occurs with patch-burning. Extreme fluctuations in productivity of both taxa, due to inter-annual rainfall variability, have a much greater impact on supply than harvest effects. Landscape-scale degradation (including cattle grazing and wildfire) affected ecological sustainability according to participants. By contrast, we found that sustainability of bush food trade is more strongly impacted by social and economic factors. The relationship-based links between harvesters and traders are critical to monetary trade. Harvesters and traders identified access to productive lands and narrow economic margins between costs and returns as issues for the future sustainability of harvest and trade. Harvesters and the reference group emphasised that sustaining bush harvest relies on future generations having necessary knowledge and skills; these are extremely vulnerable to loss. Aboriginal people derive multiple livelihood benefits from harvest and trade. Aboriginal custodians and harvester groups involved in recent trade are more likely to benefit from research and development investment to inter-generational knowledge and skill transfer than from investments in plant breeding and commercial horticultural development. In an inductive comparison, our study found there to be strong alignment between key findings about the strategies used by harvesters and traders in bush produce and the ‘desert system’..

Effects of invasive knapweed (Centaurea stoebe subsp. micranthos) on a threatened native thistle (Cirsium pitcheri) vary with environment and life stage

Botany ◽  
2015 ◽  
Vol 93 (9) ◽  
pp. 543-558 ◽  
Author(s):  
Tatyana A. Rand ◽  
Svata M. Louda ◽  
Kate M. Bradley ◽  
Kimberly K. Crider
Keyword(s):  
Invasive Plant ◽  
Lake Michigan ◽  
Life Stage ◽  
Seedling Emergence ◽  
Native Plant ◽  
Endemic Plant ◽  
Centaurea Stoebe ◽  
Seed Addition ◽  
Negative Effect ◽  
Cirsium Pitcheri

We examined the type and magnitude of invasive plant (Centaurea stoebe subsp. micranthos (Gugler) Hayek) effects on the demographic parameters of a rare plant (Cirsium pitcheri Torr. & A.Gray), using two seed addition experiments with three treatments in two dune habitats — lakeshore linear dunes and high perched dunes on Lake Michigan, USA. Treatments were near Centaurea stoebe subsp. micranthos, near a native plant, or in the open. Seedling emergence, establishment, and juvenile survivorship were significantly higher on perched dunes, with higher surface soil moisture, than on lakeshore dunes. Treatment effects varied significantly with habitat and life stage. Seedling establishment decreased near Centaurea stoebe subsp. micranthos on lakeshore dunes, but increased near any neighbor on perched dunes. However, juvenile survival was significantly lower near Centaurea stoebe. subsp. micranthos in both habitats. The probability of reaching the adult flowering stage was much lower, and occurred later, for plants near Centaurea stoebe subsp. micranthos, especially on lakeshore dunes. Thus, Centaurea stoebe subsp. micranthos had a strong negative effect on establishment, survival, and flowering of Cirsium pitcheri, but interaction intensity varied with habitat and life stage. The results suggest that coupling seed addition with watering and invasive plant removal could bolster populations of this rare endemic plant.

Soil seals in tropical tall grass pastures of northern Australia

Soil Research ◽  
1979 ◽  
Vol 17 (3) ◽  
pp. 483 ◽  
Author(s):  
J Mott ◽  
BJ Bridge ◽  
W Arndt
Keyword(s):  
Surface Soil ◽  
Seedling Emergence ◽  
Perennial Grass ◽  
Soil Surface ◽  
Mechanical Impedance ◽  
Organic Carbon Content ◽  
Grass Cover ◽  
Northern Australia ◽  
Tall Grass ◽  
Pastoral Management

Stable bare degraded areas exist in the lightly grazed perennial grass understorey existing in the eucalypt woodlands of northern Australia. Examination of these areas showed large differences in infiltration which led to increased runoff from the bare sites. However, there was little difference in soil composition between grass-covered and degraded sites apart from a higher organic carbon content in surface soil under grass. Micromorphological examination showed that soil without grass cover had lost its original open structure in the surface layers, developing a surface seal. The surface soil of the bare sealed area was shown to slake readily under quick wetting in contrast to soil surface under grass cover which did not slake. Heavy grazing of the grass understorey destroyed grass clumps within two wet seasons. Once the clumps were killed the soil surface quickly collapsed to form sealed areas, with the same properties as those occurring in ungrazed sites. The persistence of the bare sealed areas is attributed to seed removal during runoff, high temperatures and low moisture content in the sealed layer, as well as mechanical impedance preventing seedling emergence. As re-establishment of native grasses is difficult in this region, care must be taken in pastoral management to prevent the formation of degraded sites, which may take many years to re-vegetate.

Interspecific competitive potential of wavyleaf basketgrass (Oplismenus undulatifolius), a recent introduction to the mid-Atlantic United States

2020 ◽  
Vol 13 (1) ◽  
pp. 23-29
Author(s):  
Cody Kepner ◽  
Vanessa B. Beauchamp
Keyword(s):  
United States ◽  
Interspecific Competition ◽  
Invasive Plant ◽  
Perennial Grass ◽  
Community Diversity ◽  
Grass Species ◽  
Native Plant ◽  
Potential Threat ◽  
Japanese Stiltgrass ◽  
Wavyleaf Basketgrass

AbstractUnderstanding the mechanisms by which an invasive plant species is able to colonize and successfully expand into native plant communities can help in estimating the potential threat posed by a new invader and predict impacts on community diversity, structure, and function. Wavyleaf basketgrass [Oplismenus undulatifolius (Ard.) P. Beauv.] is a perennial, shade-tolerant grass species that has been recently introduced to the mid-Atlantic United States. Areas invaded by O. undulatifolius typically have low species richness, but it is unknown whether O. undulatifoius actively outcompetes other species or simply thrives primarily in species-poor habitats. This study used a greenhouse experiment to quantify interspecific competition in shade and sun among seedlings of O. undulatifolius; Japanese stiltgrass [Microstegium vimineum (Trin.) A. Camus], an invasive annual grass common in the region; and a mix of three native perennial grass species commonly used in restoring areas invaded by M. vimineum. In this experiment, shade did not significantly affect growth or competitive ability. Interspecific competition irrespective of shade had a negative effect on growth of all species, but O. undulatifolius was affected to a much greater degree than either M. vimineum or the native grass mix. These results suggest that, at least under these conditions, O. undulatifolius is a weak interspecific competitor and may be capable of forming dense monotypic stands only in areas that already have low species diversity. In the mid-Atlantic region, postagricultural legacies and overabundant deer populations, which lead to depauperate understories, may be a major facilitator of O. undulatifolius invasion in forests.

Effect of Forage Kochia on Seedling Growth of Cheatgrass (Bromus tectorum) and Perennial Grasses

2018 ◽  
Vol 11 (4) ◽  
pp. 201-207
Author(s):  
Parmeshwor Aryal ◽  
M. Anowarul Islam
Keyword(s):  
Seedling Growth ◽  
Aboveground Biomass ◽  
Bromus Tectorum ◽  
Perennial Grass ◽  
Perennial Grasses ◽  
Grass Species ◽  
Native Grasses ◽  
Native Plant ◽  
Competitive Effect ◽  
Forage Kochia

AbstractForage kochia [Bassia prostrata(L.) A. J. Scott] is competitive with annual weeds and has potential for use in reclamation of disturbed land. However, land managers are reluctant to use forage kochia in revegetation programs due to lack of understanding of its compatibility with or invasiveness in the native plant community. We conducted two greenhouse experiments, one to compare the competitive effect of forage kochia versus perennial grasses on growth of cheatgrass (Bromus tectorumL.) and one to study the effect of forage kochia on growth of native perennial grasses. In the first experiment, a single seedling ofB. tectorumwas grown with increasing neighbor densities (0 to 5 seedlings pot−1) of either forage kochia, crested wheatgrass [Agropyron cristatum(L.) Gaertner ×A. desertorum(Fisch. ex Link) Schultes; nonnative perennial grass], or thickspike wheatgrass [Elymus lanceolatus(Scribn. & J. G. Sm.) Gould; native perennial grass].Bromus tectorumgrowth was reduced moderately by all three perennial neighbors, butA. cristatumandE. lanceolatushad more effect onB. tectorumwhen compared with forage kochia. This experiment was repeated and similar results were observed. In the second experiment, forage kochia was grown with each of four native cool-season grass species: basin wildrye [Leymus cinereus(Scribn. & Merr.) Á. Löve], bluebunch wheatgrass [Pseudoroegneria spicata(Pursh) Á. Löve],E. lanceolatus, and western wheatgrass [Pascopyrum smithii(Rydb.) Á. Löve]. Forage kochia had no effect on height, tiller number, and aboveground biomass of native grasses. Similarly, native grasses did not show a significant effect on forage kochia seedlings. This experiment was also repeated, and forage kochia somewhat reduced the aboveground biomass ofL. cinereusandP. spicata. However, all native grasses significantly reduced change in height, branching, and aboveground biomass of forage kochia. These results suggest that forage kochia interfered withB. tectorumseedling growth, but it showed little competitive effect on native grass seedlings.

scholarly journals Basking and diurnal foraging in the dasyurid marsupial Pseudantechinus macdonnellensis

2008 ◽  
Vol 56 (2) ◽  
pp. 129 ◽  
Author(s):  
Chris R. Pavey ◽  
Fritz Geiser
Keyword(s):  
Predation Risk ◽  
Arid Zone ◽  
Activity Patterns ◽  
Active Phase ◽  
Temperature Sensitive ◽  
Body Temperatures ◽  
Mammal Species ◽  
Energetic Costs ◽  
Trade Offs

Several mammal species bask to passively rewarm during arousal from torpor, a strategy that can decrease energetic costs. Nothing is known about basking behaviour in these species or the trade-offs between energetic benefits of basking and potential costs associated with changes in activity patterns and increased predation risk. We assessed basking during winter in Pseudantechinus macdonnellensis, an Australian arid-zone marsupial that belongs to a family (Dasyuridae) that is typically nocturnal. Animals were implanted with temperature-sensitive transmitters to assess body temperatures and to assist in visually locating animals active during the day. Tagged animals regularly exhibited diurnal foraging. Foraging bouts occurred throughout the day; however, most bouts were observed within 3 h of sunset. By comparison, basking occurred much more frequently in the morning. Basking and a shift towards diurnal foraging in winter is associated with a decrease in richness and abundance of predators. P. macdonnellensis appears to compensate for the occurrence of torpor during the active phase (i.e. night) in winter by changing activity patterns such that foraging commences during what is usually the rest phase. These activity patterns are not expected to occur during the remainder of the year.

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