Search Results (7)

DNA analysis of environmental samples (eDNA) provides a non-intrusive approach to identify organisms, characterize biological communities, and assess biodiversity, including the detection and monitoring of invasive plant effects. However, the use of eDNA for specific applications, such as targeted-species detection, geographic and floral source tracing, and assessment of invasive plant ecological and environmental effects, requires the development of species-specific genetic primers. Chinese tallow (Triadica sebifera (L.) Small) is a non-native high-impact invader, capable of changing fire regimes, native biodiversity, nutrient cycling, and wildlife habitat and populations, that is expanding in range and abundance throughout the southern United States. In this study, we investigated and identified specific genetic sites, markers, in the tallow chloroplast genome and developed sets of primers for tallow eDNA detection. Two sets of tallow primers were developed, tallow-specific primers and tallow-related primers. Both sets of primers can be used for tallow eDNA detection, with higher target specificity for tallow-specific primers. Primers were subsequently validated for target specificity against closely related species, samples of tallow tissue, and honey and honey bee-collected pollen from areas with tallow. We found that tallow-specific primers differentiated tallow eDNA from closely related species, demonstrating target specificity. Furthermore, a sequence analysis of the tallow-related primers in the polymerase chain reaction accurately distinguished members of the Hippomaninae subtribe, including tallow, from other subtribe or subfamily members within the Euphorbiaceae. Ultimately, the genetic markers and the corresponding sets of primers will facilitate eDNA analysis of tallow for several applications, including detection and monitoring in water and soil, assurance of honey quality and floral source tracing, and perhaps serving as a model for determining plant use by pollinators. Full article

Addressing the prevalent issue of excessive fat consumption in contemporary diets, a novel method has been devised for the preparation of an emulsion gel enriched with healthful fatty acids which possesses superior emulsification characteristics. This innovative approach aims to serve as a viable substitute for the fat content in beef mince. This paper aims to evaluate the effect of emulsion gels, formulated primarily with Chinese yam as the key ingredient, on the emulsification properties and microstructural characteristics of beef mince. The findings indicate that, when the proportion of fat substituted by the emulsion gel reaches 50%, the surface hydrophobicity of the beef mince attains a value of 37.34%, which approximates that of beef tallow. Furthermore, the water retention capacity of this formulation is significantly superior to that of the other test groups (p < 0.05). Additionally, when the fat replacement with emulsion gel is increased to 75%, the protein solubility is observed to be 22.85 mg/mL. As the quantity of emulsion gel increases, the gel structure of the beef mince undergoes a gradual densification. This alteration is accompanied by a statistically significant upward trend in the overall α-helix content (p < 0.05), whereas the β-turn angle exhibits an opposite trend and the β-sheet content demonstrates a biphasic pattern, initially increasing and subsequently decreasing. Notably, the random coil of the emulsion gel reaches its minimum when the fat content is at 50%, corresponding to a state of maximal stability in the beef mince. This study provides a basis for developing research into meat products with a healthier fat profile. Full article

Leaf litter is an important input to freshwater systems. Leaves provide carbon, nutrients, and secondary compounds. We examined the effects of tree leaf species on chlorophyll a concentration—a proxy for phytoplankton biomass. We found that an input of Chinese tallow (Triadica sebiferum, invasive in the southeastern USA) and red maple (Acer rubrum) leaves resulted in lower chlorophyll concentrations than controls and other native species. These leaf species also leached tannins, resulting in a darker water color, and either may have caused the patterns observed. To separate these potential mechanisms (darker water leading to light limitation and tannin toxicity), we conducted a second experiment with a fully factorial design manipulating tannins and water color. We found that darker water resulted in the lowest chlorophyll concentration, suggesting light limitation. In the clear-water treatment, the addition of tannic acid lowered chlorophyll concentrations but also resulted in moderately darker water by the end of the experiment. The tannic acid may have been toxic to the algae, or there may have been some light limitation. Our results suggest that tannins that darken water color may substantially suppress phytoplankton and that tree species composition may influence both phytoplankton and the brownification of freshwater. Full article

Chinese tallow is a non-native invasive tree expanding in range and abundance throughout the southern United States. Several biogeographical studies mapping tallow distribution and examining key underlying environmental factors relied on the U.S. Forest Service Forest Inventory and Analysis (FIA) data, representing forestlands at scales of ~2400 ha. However, given that most invasive trees, like tallow, are cosmopolitan and dynamic in nature, FIA data fails to capture the extent and severity of the invasion especially outside areas classified as forestlands. To develop tallow maps that more adequately depict its distribution at finer spatial scales and to capture observations in non-forestlands, we combined verified citizen science observations with FIA data. Further, we described spatiotemporal patterns and compared citizen science to FIA and other previously published distribution maps. From our work, although tallow is prevalent in the south, Louisiana, Texas, and Mississippi were the most invaded states. Tallow was associated with flatwoods and prairie grasslands of the Gulf Coast. Annual extreme minimum temperatures of less than −12.2 °C (10 °F) represented the northern limit of naturalized tallow populations. Tallow’s northward and inland expansion was captured in citizen science and FIA data, indicating a tallow spread rate ranging from 5 to 20 km annually over the last decade. Systematic sampling, such as FIA, and citizen science data both have their own unique pitfalls. However, the use of citizen science data can complement invasive plant distribution mapping, especially when combined with data from established systematic monitoring networks. This approach provides for a more complete understanding of invasive tree extent and spatiotemporal dynamics across large landscapes. Full article

In 1989, Hurricane Hugo inflicted catastrophic damage on approximately 1.8 million ha of forested land in South Carolina. The purpose of this study was to monitor species compositional shifts and structural changes in several forest types following the hurricane’s disturbance. The immediate consequences of hurricane damage are well documented, but there are few studies based on the long-term compositional and structural changes that may result from hurricane disturbance, especially in temperate forest ecosystems. Forty-two forested plots were monitored within four study areas that received varying degrees of hurricane damage. Inventories included species, damage class, tree diameter, and regeneration. The objectives of this study were (1) to compare the recovery speed of wetland forests (e.g., bottomland hardwood swamps and cypress-tupelo swamps) to that of upland pine and hardwood forests; (2) to discover how the degree of hurricane damage can affect the timing and the pattern of forest recovery in the coastal plain; and (3) to compare individual species response patterns across different forest types and at different levels of initial damage. Over the 27-year period following the hurricane, successional pathways have been variable among plots of different forest types and intensity of initial disturbance. We have observed an expected increase in basal area (BA) following the disturbance. Sapling populations in many species have increased dramatically, and some of these populations have begun to thin in recent years. In several forest types, loblolly pine (Pinus taeda L.—not a predominant species in these sites prior to the hurricane) responded quickly and overtook some dominant species in BA and tree/sapling abundance. Several other species that were not a major component of the tree strata (wax myrtle [Morella cerifera (L.) Small], green ash [Fraxinus pennsylvanica Marsh.], and the invasive Chinese tallow [Triadica sebifera (L.) Small]) showed a large increase in sapling population. Overall, recovery speed and species resilience were specific to forest types and damage severity. The intensity and frequency of hurricanes may increase in the future as sea surface temperatures rise. Understanding how coastal forests respond to major hurricanes in the short-term and the long-term will aid us in preparing for future hurricanes and for potential changes in disturbance regimes. Full article

Right-of-way (ROW) land areas are required for all publicly owned transportation roadways representing over 40 million acres within the US alone. These relatively unused land assets could support potential farming land for plants and algae that contain high levels of lipids that could be used in the energy industry as an alternative fuel source. This process would offer many benefits including more efficient use of public land, eliminating mowing maintenance, increasing the bioenergy use in the US, providing visually appealing viewscapes, and helping to naturally reduce localized carbon dioxide. This paper analyzed the feasibility and potential optimization strategies of using this concept in the South-Eastern United States by scaling and comparing many of the benefits and risks associated with the selected lipid sources (soybeans, flax, sunflowers, Tung trees, Chinese tallow tree, and microalgae). Based on this assessment, the most attractive option appears to be growing flax in the winter and sunflowers in the summer with Tung Trees grown year-round as an alternative option. This would maximize lipids output while preserving and enhancing right-of-way land areas. Full article

In the Gulf of Mexico coastal region, prescribed fire has been increasingly used as a management tool to restore declining native ecosystems, but it also increases the threat posed by biological invasion, since the treated sites are more susceptible to invasive species such as Chinese tallow (Triadica sebifera). We chose Mississippi Sandhill Crane National Wildlife Refuge (MSCNWR), a fire-managed landscape, to examine the potential effect of prescribed fire and landscape/community features on tallow invasion and spread. We took a complete survey of roadways and fire lines for tallow and measured a systematic sample of 144 10 × 3 m² rectangular plots along two selected roadways and a simple random sample of 56 0.04-ha circular plots across burn units. We used pair correlation function for marked point pattern data, zero-inflated negative binomial models for count data, as well as multivariate Hotelling’s T² test, to analyze the effect of prescribed fire and landscape/community characteristics on tallow invasion and spread along habitat edges and into interiors. Our results show that tallow spread along habitat edges and into interiors in a spatially clustered pattern. Tallow invasion risk decreases with the distance to seed trees and shrub coverage, and with the time since last fire if seed trees are outside the effective seed dispersal range (~300 m), but increases with the time since last fire if seed trees are within the effective seed dispersal range. Tallow seedling (≤2 years old) densities increase with the time since last fire and with increasing overstory tree basal area, but decrease with the distance to seed trees. Tallow-invaded interior plots have significantly shorter mean fire return intervals (2.7 years), lower shrub coverage (8.6%), and are closer to edges (20.3 m) than non-invaded plots (4.3 years, 18.4%, 167.6 m, respectively). Full article