Native Seeds Research Articles

Estimation of gut passage time of wild, free roaming forest elephants

Seed gut passage times, the time from ingestion to defecation, and frugivore movement patterns determine patterns of seed deposition across the landscape and are thus crucial parameters to quantify in wild populations. Recent advancements in satellite and telemetry technologies mean that animal movement patterns are readily quantifiable in increasingly high resolution. However, data on wild frugivore gut passage times are scarce to non-existent due to the difficulty of monitoring seed ingestion and defecation in natural habitats; therefore, GPT estimates are often extrapolated from captive species whose diets and activity patterns may have limited transferability to free-ranging populations. Here we develop, trial and deploy a suite of model seeds to address this shortfall in wild African forest elephants Loxodonta cyclotis – one of the most effective seed dispersers in the tropics. We use a combination of ‘active’ seed mimics, which indirectly measure gut passage through recording temperature fluctuations, and ‘passive’ seed mimics, which serve to mark the point of defecation to allow gut passage estimation from time-stamped GPS collar data. In doing so, we present the first ever GPT estimates from wild forest elephants: mean = 39.8 h (min = 16.6 h; max = 113.7 h). The estimates were derived exclusively from passive seed mimics (plastic beads and modified native seeds) as all active seed mimics were rejected by the focal elephant. The methods described are translatable to other free-ranging, GPS-collared, species and if widely adopted, will begin to address the current gap in our understanding of seed dispersal by wild frugivores.

Edible seeds, leaves and flowers as Maya Super Foods: Function and composition

Mesoamerica is a megadiverse region where one of the Vavilov center has developed; Guatemala is part of this region, and the heart of the Mayan world. The biodiversity include the traditional utilization of food (grains, fruits, herbs, flowers and rhizomes), flavors, aromas, condiments, dyes and colorants, medicinal and ritual plants, as well as other products from nature. At least 76 vegetal species were developed as food. In this paper it will be presented the information on seeds and grains (Amaranthus cruentus, Brosimum alicastrum, Crescentia alata, Cucurbita pepo, Phaseolus vulgaris, Salvia hispanica, Theobroma cacao, Zea mays), herbs (Amaranthus hybridus, Cnidoscolus aconitifolius, Crotalaria longirostrata, Dysphania ambrosioides, Lycianthes synanthera, Solanum americanum, S. nigrescens, S. wendlandii), and flowers (Cucurbita pepo, Chamedoroea tepejilote, Fernaldia pandurata, Erythrina berteroana, Gliricidia sepium, Yucca elephantipes,) traditionally used as food. Other foods include fruits, rhizomes, tubers and condiments. The functional properties and nutritive composition are described for 22 native seeds, leaves and flowers. In comparison with recognized international herbs, it is demonstrated that some native Mesoamerican herbs have an important nutritious and functional composition. A rich traditional culinary heritage is the way that these foods are consumed. The use of traditional dishes and innovative fusions with Maya Super Foods is recommended for economy improvement of the region as well as health and beauty.

Attraction of green lacewings (Neuroptera: Chrysopidae) to native plants used as ground cover in woody Mediterranean agroecosystems

Using native seeds to establish semi-natural habitats is a novel strategy to restore biodiversity and ecosystem services such as biological control. As green lacewings (Neuroptera: Chrysopidae) are regarded as major biological control agents in different crops, the objective of this study was to test the attractiveness of selected native plant species to lacewings. During a two-year (2016–2017) field experiment near Villarrubia (Andalusia, Spain), 42 native plant species belonging to 13 families were planted. Plant development was monitored, and arthropods were vacuumed from each plot twice during the peak May flowering period. Green lacewings were observed to use 28 of the 36 well developed species to reproduce, feed and/or rest. Chrysoperla lucasina was the predominant species among the captured adults. No clear pattern of attraction common to all species was observed during the two-year sampling period. In 2017, eight plant species showed above-average chrysopid abundance. In addition, Acari abundance correlated positively with chrysopid abundance. Given the attraction of chrysopids, the effect of pests and disease on olive orchards and satisfactory plant development, we consider Biscutella auriculata, Borago officinalis, Silene colorata, Crepis capillaris, Nigella damascena and Papaver rhoeas to be the native plant species best suited to host chrysopids and to restore ground cover in perennial Mediterranean crops.

Factoring restoration practitioner perceptions into future design of mechanical direct seeders for native seeds

The methods used to distribute seeds influence the success of a restoration project. We surveyed 183 restoration practitioners from across the globe with the aim of identifying common limitations to the effective use of mechanical direct seeding in large‐scale restoration practice to highlight avenues for design improvement to mechanized seeding equipment. Results from this survey show that direct seeding methods are commonly used for ecological restoration and agree with other studies that suggest the method can achieve results much quicker and cheaper than the alternative of distributing nursery‐grown tube stock. However, this study indicates that current mechanical direct seeding methods lack adequate control of seed sowing depth and spatial distribution and highlight that the inability to sow seeds of varying morphology over complex topography are common limitations to direct seeding. To improve restoration success, engineering improvements to mechanical direct seeders used in large‐scale restoration should focus in particular on addressing issues of precision of delivery for diverse seed types and landscapes.

Caries as an archaeological problem-solving tool: reconstructing subsistence patterns in late prehistoric west-central Tennessee

The dentition from two Middle Mississippian period (~AD 1100-1350) site samples (Gray Farm [~AD 1150-1400], Link/Slayden [~AD 1200-1400]) from the Kentucky Lake Reservoir of west-central Tennessee area are examined for the presence of caries to assess whether a maize-intensive subsistence economy is evident or the retention of the cultivation of domesticated native seeds (i.e., the Eastern Agricultural Complex). Given the absence of archaeological context, the caries prevalence operates as an archaeological problem-solving tool. The caries prevalence by tooth type are compared to a Late Woodland period (~AD 400-900) site sample (Hobbs) from the Kentucky Lake Reservoir as well as three unequivocal maize-intensive site samples from the Late Mississippian period (~AD 1300-1550) of East Tennessee. The Gray Farm site aligns statistically with the maize-intensive samples; Link/Slayden does not and resembles the caries prevalence of the Hobbs sample. The Mississippianization process in the Kentucky Lake Reservoir clearly varies in the adoption of maize as a primary cultigen. This may reflect the difference in geo-political location of Gray Farm and Link/Slayden relative to neighboring Mississippian economies, particularly to the east (Middle Cumberland Culture), or it may reflect potential temporal differences among the Middle Mississippian period settlements within the Kentucky Lake Reservoir.

Iron and manganese as dopants used in the crystallization of highly resistive HVPE-GaN on native seeds

An influence of doping with iron and manganese on GaN crystallized by halide vapor phase epitaxy is described in this work. This is a continuation of previous work where solid iron was used as a metal precursor and semi-insulating GaN co-doped with manganese and iron was crystallized. In this paper, metals of the highest purity were used. The acceptors (iron and manganese) were incorporated separately in order to compensate unintentional donors present in undoped GaN crystals. Native GaN wafers were used as seeds. The crystallized doped samples were examined in terms of their structural and electrical properties. Concentrations of dopants and unwanted impurities were determined. Iron-doped and Mn-doped GaN, with resistivity at room temperature exceeding 107 Ωcm, was presented and compared. It was shown that, at room temperature, for the same acceptor concentration, GaN:Mn crystals present better structural quality and higher resistivity than GaN:Fe.

Invasive birds spread native seeds

Ecological Networks When humans introduce exotic species to sensitive ecosystems, invasion and extinction of native species often follow. The resulting ecological communities can develop unusual interactions between the survivors and newcomers. Vizentin-Bugoni et al. analyzed the structure of seed dispersal networks in Hawai'i, where native bird species have been mostly replaced by invaders. They found that the native plants now depend on the invasive birds for seed dispersal. The network of dispersal interactions is complex and stable, which are features of native seed-dispersal networks in other parts of the world. It appears that introduced species may, in some circumstances, become integrated into native ecosystems. Science , this issue p. [78][1] [1]: /lookup/volpage/364/78?iss=6435

Effects of Introduced Plants on Diet and Seed Preferences of Pogonomyrmex carbonarius (Hymenoptera: Formicidae) in the Patagonian Steppe.

Invasive species may interact with resident species and disrupt previously established interactions, with effects on the whole community. If introduced seeds are selectively consumed by native granivores, this could limit the establishment or spread of invasive plants (biotic resistance), and reduce the predation pressure upon native seeds. We determined if the presence of introduced plants affects the diet and the seed preferences of the ant Pogonomyrmex carbonarius (Mayr) in a Patagonian steppe. We expected a higher proportion of introduced seeds in the diet of nests located in areas with a high abundance of introduced species (roadsides) than in nests located in low invaded areas. Diet composition was obtained by collecting items retrieved by workers to colonies and compared between areas of contrasting abundance of introduced species. Field-based choice experiments were performed to evaluate whether exotic seeds were preferred to native ones under a paired comparisons design. Native seeds predominated in the diet. A low proportion of introduced species were included only in colonies close to the road. Ants preferred native seeds to introduced ones, and showed a marked preference for seeds of the native grass Pappostipa speciosa (Trin. & Rupr.) Romasch. (Poaceae), typical of the Patagonian steppe. The presence of introduced plants had little influence on interactions of P. carbonarius with seeds in the Patagonian steppe. Therefore, this ant species would not exert a control on the studied introduced plants, illustrating a case of low biotic resistance to invasion by these species.

Native seeds incorporated into activated carbon pods applied concurrently with indaziflam: a new strategy for restoring annual‐invaded communities?

Reestablishing native perennial vegetation in annual grass‐invaded rangelands is critical to restoring ecosystems. Control of exotics, often achieved with preemergent herbicides, is essential for successful restoration of invaded rangelands. Unfortunately, desirable species cannot be seeded simultaneously with preemergent herbicide application due to nontarget damage. To avoid this, seeding is commonly delayed at least 1 year. Delaying seeding increases the likelihood that annual grasses will begin reestablishing and compete with seeded species. Activated carbon (AC) can provide preemergent herbicide protection for seeded species because it adsorbs and deactivates herbicides. Previous studies suggest that a cylindrical herbicide protection pod (HPP), containing AC and seeds, allows desired species to be seeded simultaneously with the application of the preemergent herbicide imazapic. Unfortunately, imazapic is only effective at controlling annual grasses for 1–2 years. Indaziflam is a new preemergent herbicide which exhibits longer soil activity, with which HPPs may be useful. To assess this possibility, we evaluated seeding two native species (Wyoming big sagebrush [Artemisia tridentata Nutt ssp. wyomingensis] and bluebunch wheatgrass [Pseudoroegneria spicata (Pursh) Á. Löve]), both incorporated into HPPs and as bare seed, at four application rates of indaziflam in a grow room study. HPPs protected seeded species at low, mid, and high rates of indaziflam. The abundance and size of plants was greater in HPPs compared to bare seed treatments. These results suggest that HPPs can be used to seed native grasses and shrubs simultaneously with indaziflam application.

How policies constrain native seed supply for restoration in Brazil

Large‐scale ecological restoration programs across the world involve a voluminous demand for native seeds of diverse native plant species. In this article, we explore how institutional systems have operated and impacted native seed supply in Brazil. Native seed supply for restoration is essentially a community‐based activity which faces broad barriers to operating within regulations because of requirements for excessive and costly technical documentation, scarcity of seed laboratories, and lack of instructions for native seed quality testing. Although decentralized seed networks have stimulated arrangements for local organizations to promote seed supply, policies constrain the development of local capacities and the ongoing sustainability of these organizations. These conditions have resulted in a vast network of informal collectors and producers who are largely “invisible” and unknown to the regulatory authorities. Policies have decentralized responsibilities from the state without devolving decision‐making power to the multiple stakeholders engaged in policy elaboration. The policies maintain the centralized regulation of native seed supply. After examining Brazilian seed networks' experiences and conducting discussions with stakeholders and experts, we suggest adapting the current regulations to more local level contexts, encompassing the following strategies: (1) ensuring native seed origin and identity; (2) relaxation of the laboratory accreditation process for native seed quality assurance; (3) fostering seed markets for restoration; (4) research to provide technological innovation; (5) supporting local, diverse, and small seed‐based businesses.

Invasive grass affects seed viability of native perennial shrubs in arid woodlands

It is often assumed that declines in native vegetation associated with alien plant invasion are driven by competition between plants for limited resources. However, invasion can also impact native plants through recruitment limitation mechanisms. We examined the effects of Cenchrus ciliaris L. (buffel grass, an alien pasture species) on the seed viability and germination of two native perennial shrubs (Acacia tetragonophylla and A. victoriae) in arid woodlands of central Australia. Dormancy, germination rate and seed viability were assessed using laboratory-based germination assays on seeds collected from the soil and mature shrubs in: (1) woodland invaded by buffel grass and (2) areas in which buffel grass had been removed and reinvasion prevented for at least 7 years. There was a twofold increase in viability of A. victoriae seeds in buffel grass-removed compared with invaded sites, and a faster germination rate (T50) for A. tetragonophylla in buffel grass-removed sites. Acacia victoriae seed mass was reduced by approximately 25% in invaded areas, associated with decomposed or absent embryos. Invasion may limit native recruitment by reducing the viability and germination rate of native seeds prior to dispersal from parent plants. Reduced seed viability would reduce seed bank accumulation and total available seed for A. victoriae, while slower germination rates would minimise the efficiency by which A. tetragonophylla responds to sporadic rainfall events. Both mechanisms could lead to long term declines in native plant populations. Reduced seed viability would compound interference of buffel grass on recruiting plants.

Native Seeds: An Unrecognized and Undervalued Resource

Native Seeds: An Unrecognized and Undervalued Resource

Overview of Selected Native Seeds in Agricultural Wastes and its Properties

Agricultural waste is considered as the valuable assert in the world, they can be actively used as fibers, fertilizer, biogas production, softwood furniture manufacturing etc. However, limitations are to be taken into account. Generally, seeds play a major role in agricultural waste which indicated with huge amount of nutritive value and phytoconstituents. They reflect the therapeutic activity. In this review, we discussed the seeds phytoconstituents and their utility as bioactive agent. In near future, it would be efficient to gain knowledge of seeds which is considered as a waste in their therapeutic evaluation and also as nutritive value.

Protecting direct seeded grasses from herbicide application: can new extruded pellet formulations be used in restoring natural plant communities?

Restoration of native plant communities through direct seeding often experience low seedling establishment success rates, partly due to competition with invasive weed species. To improve seeding success, herbicides can be applied to control weed competition, however, this can have negative impacts on the seeded species. Activated carbon (AC) can be incorporated into newly developed seed enhancement technologies to adsorb herbicides and increase seedling tolerance. This study expands upon research completed to date, by developing new formulations of extruded pellets containing AC, aiming to provide increased protection to seeded species and increase herbicide selectivity. We tested six extruded pellet formulations, which included two pellet formula variations, and three quantities of AC, to examine the impact on emergence (without herbicide) and mortality (with herbicide) of Lolium rigidum Gaudin (annual ryegrass). Extruded pellet formulations containing a superabsorbent polymer (3%) and AC (10%) did not impede emergence (79%), in the absence of herbicide, similar to the non‐pelleted seeds (81%). This extruded pellet formulation increased seedling tolerance to Simazine (a pre‐emergent, soil applied herbicide) application, with mortality reduced from 96% in non‐pelleted seeds, and 77% in pellets containing no AC, to 22% in pellets containing AC. The results from this study demonstrate that AC extruded pelleting can be used as a restoration seeding technology by protecting seeds from the negative effects of pre‐emergent herbicide applications. Field evaluations with native seeds will mark an important step forward to ensure seed enhancement technology options, such as AC extruded pelleting, are available for restoring natural plant communities in restoration programs.

Post-fire invasion in Torres del Paine Biosphere Reserve: the role of seed tolerance to heat

Biological invasions are one of the major causes of biodiversity loss. Anthropogenic alteration in fire regimes has promoted plant invasion in several regions and ecosystems worldwide, especially in those where fires are historically rare. This is the case of the UNESCO Biosphere Reserve Torres del Paine National Park (TPNP), located in southern South America. In this study, we hypothesised that the seeds of native species of the TPNP do not resist fire-related high soil temperatures as do exotic plants, which could facilitate the spread of exotic plant invasion in post-fire environments. To test this hypothesis, we exposed seeds of plant species collected from the TPNP to different heat doses (60°C, 5min; 90°C, 5min; 90°C, 10min; 120°C, 5min) and compared their final germination and viability with those of unheated seeds. The study was conducted on five native species and three aliens inhabiting the TPNP. Almost all the seeds of native species died after exposure to temperatures higher than 60°C, whereas seeds of the alien species resisted higher heat doses. The on-site resistance of the aliens (through fire-tolerant soil seed banks) and the fire sensitivity of native seeds contribute to our understanding on post-fire invasion in the TPNP.

Mycorrhizal divergence and selection against immigrant seeds in forest and dune populations of the partially mycoheterotrophic Pyrola rotundifolia.

Plant populations occupying different habitats may diverge from each other over time and gradually accumulate genetic and morphological differences, ultimately resulting in ecotype or even species formation. In plant species that critically rely on mycorrhizal fungi, differences in mycorrhizal communities can contribute to ecological isolation by reducing or even inhibiting germination of immigrant seeds. In this study, we investigated whether the mycorrhizal communities available in the soil and associating with the roots of seedlings and adult plants of the partially mycoheterotrophic Pyrola rotundifolia differed between populations growing in sand dunes and forests. In addition, reciprocal germination experiments were performed to test whether native seeds showed higher germination than immigrant seeds. Our results showed that the mycorrhizal communities differed significantly between forest and dune populations, and that within populations seedlings and adults also associated with different mycorrhizal communities. In both forest and dune populations, mycorrhizal communities were dominated by members of the Thelephoraceae, but dune populations showed a higher incidence of members of the Inocybaceae, whereas forest populations showed a high abundance of members of the Russulaceae. Reciprocal germination experiments showed that native seeds showed a higher germination success than immigrant seeds and this effect was most pronounced in dune populations. Overall, these results demonstrate that plants of P.rotundifolia growing in dune and forest habitats associate with different mycorrhizal communities and that reduced germination of non-native seeds may contribute to reproductive isolation. We conclude that selection against immigrants may constitute an important reproductive barrier at early stages of the speciation process.

Non-redundancy in seed dispersal and germination by native and introduced frugivorous birds: implications of invasive bird impact on native plant communities

Seed dispersal by vertebrate animals is important for the establishment of many fleshy-fruited plant species. Different frugivorous species can provide different seed dispersal services according to their specific dietary preferences as well as behaviour and body traits (e.g. body size and beak size of birds). Our aim was to study redundancies and complementarities in seed dispersal and germination between the two main native seed disperser birds and the introduced silver pheasant Lophura nycthemera in the temperate Patagonian forests. For this, we collected fresh droppings from the studied species and analyzed seed content. We conducted germination trials for four plant species common in bird droppings; two native species (Aristotelia chilensis and Rhaphithamnus spinosus) and two invasive non-native species (Rubus ulmifolius and Rosa rubiginosa). Both native frugivorous birds and the silver pheasant dispersed fruits of non- native fleshy-fruited plants, but their roles were non-redundant in terms of species dispersed and effect on seed germination. The silver pheasant dispersed a proportionally high number of non-native seeds, while native birds dispersed a high number of native seeds. In addition, the effect of gut treatment in seed germination differed between seed dispersers. Native birds promoted the germination for the two native plant species studied, while the silver pheasant promoted the germination of one non-native plant. This suggests that seed dispersal by the silver pheasant may contribute to the spread of some invasive fleshy-fruited plants in the ecosystems that otherwise would not be dispersed by any other bird. The understanding of redundancies and complementarities on seed dispersal and germination between native and introduced birds will allow improving the management of fleshy-fruited non-native plants.

Towards a characterisation of the wild legume bitter vetch (Lathyrus linifolius L. (Reichard) Bässler): heteromorphic seedgermination, root nodule structure and N-fixing rhizobial symbionts.

Lathyrus linifolius L. (Reichard) Bässler (Fabiaceae, bitter vetch) is a nitrogen (N) fixing species. A coloniser of low nutrient (N) soils, it supports biodiversity such as key moth and butterfly species, and its roots are known for their organoleptic and claimed therapeutic properties. Thus, the species has high potential for restoration, conservation, novel cropping and as a model species. The last because of its genetic synteny with important pulse crops. However, regeneration and functional attributes of L. linifolius remain to be characterised. Seeds of L. linifolius were characterised using physical, colorimetric and chemical data. Ultrastructural and functional characterisation of the N-fixing root nodules included immunolabelling with nifH protein antibodies (recognising the N-fixing enzyme, nitrogenase). Endosymbiotic bacteria were isolated from root nodules and characterised phylogenetically using 16S rRNA, nodA and nodD gene sequences. L. linifolius yielded heteromorphic seed of distinct colour classes: green and brown. Seed morphotypes had similar C:N ratios and were equally germinable (ca. 90%) after scarification at differing optimal temperatures (16 and 20°C). Brown seeds were larger and comprised a larger proportion of the seed batch (69%). L. linifolius root nodules appeared indeterminate in structure, effective (capable of fixing atmospheric N) and having strains very similar to Rhizobium leguminosarum biovar viciae. The findings and rhizobial isolates have potential application for ecological restoration and horticulture using native seeds. Also, the data and rhizobial resources have potential applications in comparative and functional studies with related and socio-economically important crops such as Pisum, Lens and Vicia.

Invasive ants take and squander native seeds: implications for native plant communities

Seed dispersal is a fundamental process in the lifecycle of all flowering plants. Many plant species have evolved specialist associations with biotic vectors to facilitate dispersal. Such specialised interactions mean that these associations are potentially highly sensitive to disruption, e.g. from invasive species. However, despite this threat we still understand remarkably little about how such perturbations affect the dynamics and efficiency of the seed-dispersal process. In this study we quantify the impacts of an invasive ant across three key phases of the seed dispersal process: seed removal, distribution and placement, in order to determine the stages of seed dispersal most vulnerable to disruption by invaders. Using the Argentine ant (Linepithema humile) as a model, we show that invaded sites exhibited a significant decrease in seed dispersal services across all three phases of the dispersal process, relative to non-invaded sites. Seeds dispersed in invaded sites were: (a) less likely to be transported; (b) potentially distributed over a smaller spatial area, and (c) less likely to be placed at soil depths favourable for germination and establishment compared to those dispersed in non-invaded sites. These results reveal that ant-mediated seed dispersal services are significantly reduced by an invasive species at multiple stages in the dispersal process. Reductions in the efficacy of seed dispersal, combined with shifts in the ecological and geographical patterns of dispersal, may lead to cascading impacts on plant species composition and community structure. This study shows how an invasive ant can affect seed dispersal at several stages in the dispersal process.

Doping in bulk HVPE-GaN grown on native seeds – highly conductive and semi-insulating crystals

Results of gallium nitride crystallization on native seeds by Hydride Vapor Phase Epitaxy method are described. The seeds are high quality ammonothermal GaN crystals. Properties of unintentionally doped HVPE-GaN are briefly presented. A review on doping with donors and acceptors is prepared. Intentional incorporation of silicon or germanium is proposed in order to grow highly conductive HVPE-GaN. Carbon, iron, or manganese was introduced to increase the resistivity of crystallized material. GaN samples with different dopants are described in terms of their structural, optical, and electrical properties.