Lindera Melissifolia Research Articles

Leaf acclimation to soil flooding and light availability underlies photosynthetic capacity of Lindera melissifolia, an endangered shrub of bottomland forests in the Mississippi Alluvial Valley, USA.

Lindera melissifolia is an endangered shrub indigenous to the broadleaf forest of the Mississippi Alluvial Valley (MAV). In this region, extant colonies of the species are found in periodically ponded habitats where a diversity of broadleaf trees can form well-developed overstory and sub-canopies-these habitat characteristics suggest that soil flooding and light availability are primary drivers of L. melissifolia ecophysiology. To understand how these two factors affect its photosynthetic capacity, we quantified leaf characteristics and photosynthetic response of plants grown in a large-scaled, field setting of three distinct soil flooding levels (no flood, 0day; short-term flood, 45days; and extended flood, 90days) each containing three distinct light availability levels (high light, 30% shade cloth; intermediate light, 63% shade cloth; and low light, 95% shade cloth). Lindera melissifolia leaves showed marked plasticity to interacting effects of flooding and light with lamina mass per unit area (Lm/a) varying 78% and total nitrogen content per unit area (Na) varying 63% from the maximum. Photosynthetic capacity (A1800-a) ranged 123% increasing linearly with Na from low to high light. Extended flooding decreased the slope of this relationship 99% through a reduction in N availability and metabolic depression of A1800-a relative to Na. However, neither soil flooding nor light imposed an additive limitation on photosynthetic capacity when the other factor was at its most stressful level, and the A1800-a-Na relationship for plants that experienced short-term flooding suggested post-flood acclimation in photosynthetic capacity was approaching the maximal level under respective light environments. Our findings provide evidence for wide plasticity and acclimation potential of L. melissifolia photosynthetic capacity, which supports active habitat management, such as manipulation of stand structure for improved understory light environments, to benefit long-term conservation of the species in the MAV.

Intensity and mode of Lindera melissifolia reproduction are affected by flooding and light availability.

We studied the impact of flooding and light availability gradients on sexual and asexual reproduction in Lindera melissifolia (Walt.) Blume, an endangered shrub found in floodplain forests of the Mississippi Alluvial Valley (MAV), USA. A water impoundment facility was used to control the duration of soil flooding (0, 45, or 90 days), and shade houses were used to control light availability (high = 72%, intermediate = 33%, or low = 2% of ambient light) received by L. melissifolia established on native soil of the MAV. Sexual reproductive intensity, as measured by inflorescence bud count, fruit set, and drupe production, was greatest in the absence of soil flooding. Ninety days of soil flooding in the year prior to anthesis decreased inflorescence bud counts, and 45 days of soil flooding in the year of anthesis lessened fruit set and drupe production. Inflorescence bud development was the greatest in environments of intermediate light, decreased in high‐light environments, and was absent in low light environments. But low fruit set diminished drupe production in intermediate light environments as compared to high light environments. Asexual reproduction, as measured by development of new ramets, was greatest in the absence of soil flooding and where plants were grown in high or intermediate light. Plants exhibited plasticity in reproductive mode such that soil flooding increased the relative importance of asexual reproduction. The high light environment was most favorable to sexual reproduction, and reproductive mode transitioned to exclusively asexual in the low light environment. Our results raise several implications important to active management for the conservation of this imperiled plant.

Adaptive trait variation in the federally endangered Lindera melissifolia (Lauraceae), as it relates to genotype and genotype-environment interaction1

Molecular markers have shown a high level of genetic diversity in most extant populations of the federally endangered Lindera melissifolia (Walt.) Blume in the southeastern United States. However, it is unknown if diversity in adaptive traits exists. We quantified adaptive trait variation in 17 L. melissifolia genotypes by growing genets from two disjunct populations in the Lower Mississippi Alluvial Valley in a common-garden environment. We then examined genotype-environment interaction through introduction of a flooding treatment. Within a common-garden environment, variation in adaptive traits was affected by genotype. Stem height, stem diameter, leaf number, and stem architecture accounted for 56% of variation among genotypes, and an additional 23% of variation was attributed to differences in vegetative fecundity and foliar chlorophyll content. There was no divergence in plant morphology between disjunct populations. Plastic response to a winter flooding regime varied in magnitude and direction among male genotypes, and only in magnitude in female genotypes. A decrease in L. melissifolia population sizes would diminish genetic diversity, as well as adaptive trait variation, and may threaten long-term persistence of extant populations.

Biomass Accumulation in the Endangered Shrub Lindera melissifolia as Affected by Gradients of Light Availability and Soil Flooding

Biomass Accumulation in the Endangered Shrub Lindera melissifolia as Affected by Gradients of Light Availability and Soil Flooding

An Assessment of the Potential Impact of Laurel Wilt on Clonal Populations of Lindera melissifolia (Pondberry)

Lindera melissifolia (Pondberry) is a federally endangered shrub that reproduces primarily by ramets from rhizomes and occurs in scattered clonal populations in bottomland forests of the southeastern US. Like other members of the Lauraceae indigenous to the US, Pondberry is susceptible to laurel wilt, a lethal disease caused by the fungal pathogen, Raffaelea lauricola. We conducted studies to determine the impact of laurel wilt on Pondberry colonies. We grew Pondberry in pots and in raised beds for 2–5 y; during this time, multiple ramets developed around the original plants. We subsequently inoculated single Pondberry stems in colonies with R. lauricola, or mock-inoculated stems with sterile deionized water. Stems inoculated with R. lauricola began to show symptoms within 2 weeks and completely wilted in ∼4 weeks. In pot studies, R. lauricola spread through rhizomes and caused wilt in an average of 77% of ramets in one experiment and 59% in another. The wilt also spread rapidly through connecting rhizomes in field experiments, killing as many as 59 ramets at distances of up to 4 m from the inoculated stems. Although laurel wilt has been rarely documented in Pondberry, our study demonstrates that when infections by R. lauricola occur, they can have detrimental effects to Pondberry colonies.

Light availability and soil flooding regulate photosynthesis of an imperiled shrub in lowland forests of the Mississippi Alluvial Valley, USA

Physiological responses to light availability and soil flooding on Lindera melissifolia (Walt.) Blume were studied. Shrubs were grown under 70, 37 or 5% of full sunlight with either 0, 45, or 90 d of soil flooding. We measured leaf photosynthetic rate (PN) to test the hypothesis that soil flooding reduces P N in L. melissifolia following shrub acclimation to low light availability. Results showed that light availability and soil flooding interacted to affect P N. In the 0 d and 45 d flooding regimes (flood water removed 36–39 d prior to measurement), P N was similar between shrubs receiving 70% or 37% light, and these shrubs had 147% greater P N than shrubs receiving 5% light. Shrubs receiving 90 d of soil flooding had similar low rates of area-based P N regardless of light level. Similar P N between 0 d and 45 d flooded shrubs indicated physiological recovery following removal of flood water.

Growth and competitive abilities of the federally endangered Lindera melissifolia and the potentially invasive Brunnichia ovata in varying densities, hydrologic regimes, and light availabilities

Brunnichia ovata (Walter) Shinners is a native, perennial, woody vine with the potential to become an aggressive competitor of the federally endangered shrub Lindera melissifolia (Walt.) Blume. Our study simulated habitat disturbances to hydrologic regime and light availability that may occur naturally, or through active management practices aimed at ensuring the sustainability of L. melissifolia, and we determined the species responses to these changes. First-year plants of L. melissifolia and B. ovata were grown at varying densities, in flooding or nonflooding treatments, and receiving 100%, 47%, or 21% light availabilities. For both species, density effects, in combination with light availability and flooding regime influenced total biomass accumulation. Brunnichia ovata exhibited a high degree of plasticity with respect to biomass allocated between above- and below-ground tissues in response to flooding, whereas biomass allocation in L. melissifolia was relatively unaffected. Interspecific competition occurred primarily in nonflooding treatments. Our study highlighted the complexity of the relationship of L. melissifolia and B. ovata with regard to functional trait responses to changes in abiotic and biotic factors, and indicated that it will be necessary to consider entire plant community responses to mitigate increased competitive interactions and ensure the survival of L. melissifolia populations.

Pondberry (Lindera melissifolia, Lauraceae) seed and seedling dispersers and predators

Pondberry (Lindera melissifolia(Walter) Blume) is an endangered dioecious, clonal shrub that grows in periodically flooded forests of the southeastern United States. The probability of survival of dispersed pondberry seeds and new germinants is unknown, but few seedlings are noted in the forest. This study was undertaken to: (1) identify herbivores and predators of pondberry seeds and seedlings, (2) record the fate of pondberry seeds and seedlings after simulated dispersal in areas with lower and higher understory cover, and (3) calculate the probability of seed survival in the two cover types. The study was conducted in or near the Delta National Forest and the Delta Experimental Forest, MS. Pondberry seed and seedling plots were established at sites with high or low cover. Video cameras with infrared illumination were set up to monitor animal visitors to the plots. Image analysis indicated that swamp rabbits (Sylvilagus aquaticus (Bachman)) and wood rats (Neotoma floridana Ord) cut or ate seedlings, while other animals visited the plots without damaging seedlings. Numerous bird species and mammals visited the seed plots and some were filmed eating seeds. Pondberry seeds exposed in open habitats had a significantly higher survival rate than those exposed in habitats with more herbaceous and woody understory cover. The novelty and quality of the temporal data collected via video monitoring indicate the importance of this method in collecting data that are not otherwise available on endangered and rare species.

Environmental Controls of Reproduction and Early Growth ofLindera melissifolia(Lauraceae)

ABSTRACT Lindera melissifolia is a federally endangered endemic shrub of the southeastern United States. Numerous populations are gender-biased. The goal of this study was to determine environmental conditions most appropriate for establishment and growth of seedlings and adult females. Seedlings were grown under varied moisture and light to compare growth rates and morphological ratios. Seedlings were clipped to simulate two levels of disturbance, and their shoot sprouting ability was assessed. Densities of adult flowering stems, co-occurring species, and solar transmittance were analyzed within two North Carolina populations. The lowest levels of light resulted in decreased growth, but light and moisture did not interact to affect seedling growth rate significantly. Morphological ratios and growth responses followed patterns expected for plants exhibiting plasticity in response to varied light levels, but not to moisture. Clipping immature plants below root collars decreased survivorship to 31%. Growth ...

Description and Classification ofLindera melissifoliaHabitat in the Southeastern Coastal Plain

ABSTRACT Lindera melissifolia is a federally endangered wetland shrub endemic to the Southeastern Coastal Plain and the Lower Mississippi Alluvial Valley. Lindera melissifolia is known to occupy seasonally flooded habitats, but little work has been done to describe habitat characteristics in the Southeastern Coastal Plain region. This research uses vegetation and environmental data collected from 50 plots in North Carolina, South Carolina, and Georgia to develop a habitat classification and description for L. melissifolia in the Southeastern Coastal Plain. Cluster analysis, nonmetric multidimensional scaling, indicator species analysis, and analysis of variance were used to assign plots to four distinct isolated wetland habitat types. Swamp Tupelo Depression Pond and Successional Swamp Forest communities supported the densest and healthiest L. melissifolia populations, followed by Pond-Cypress Pond and Pocosin, and Limestone Sink Forest habitats. Habitat degradation and other forms of disturbance were fou...

The Endangered Pondberry (Lindera melissifolia[Walter] Blume, Lauraceae)

Pondberry (Lindera melissifolia) is an endangered plant species that occurs in seven southern states. It is a rhizomatous, clonal shrub that usually grows in colonies and has numerous stems with few branches and drooping leaves that give off a spicy odor when crushed. Pondberry is dioecious, with small yellow flowers that bloom in spring and have scarlet drupes that mature in late summer or fall. The species grows in low areas within bottomland hardwood forests in the western part of its range and on the margins of limestone sinks and wet depressions in pine forests in the eastern part. Pondberry has probably always been a rare species, but its distribution and abundance have been affected by habitat destruction and alteration, such as timber cutting, clearing of land, and local drainage or flooding of wetlands. Until recently research on pondberry has been sparse; but because of proposed flood control measures for the area in which the species occurs in Mississippi, interest in research has increased. This review will be helpful to land managers and scientists because it provides information about all known current research on the species.

Rearing Redbay Ambrosia Beetle,Xyleborus glabratus(Coleoptera: Curculionidae: Scolytinae), on Semi-Artificial Media

Semi-artificial diets consisting of redbay (Persea borbonia (L.) Spreng.; Laurales: Lauraceae) sawdust and various nutrients were tested for rearing Xyleborus glabratus Eichoff (Coleoptera: Curculionidae: Scolytinae) in vitro. Comparison of 2 media, modified and standard, adapted from Biedermann et al. (2009) showed that the more solid consistency of the modified medium resulted in greater rates of successful brood production in cultures. A 2-layered medium structure with a nutrient rich lower layer and a nutrient poor upper layer proved to be superior to a single-layered structure. Using a 2-layered structure, 72.5% of foundresses successfully produced brood, which was similar to or greater than success rates of X. glabratus under natural field conditions. The most successful media recipes used finely ground wood from redbay, but some successful brood production also occurred when wood from pondberry (Lindera melissifolia ) (Walter) Blume; Laurales: Lauraceae) and California bay laurel (Umbellularia californica (Hook. & Arn.) Nutt.; Laurales: Lauraceae) were used instead of redbay. A 2-layered structure with nutrient levels slightly higher than those in the modified medium of Biedermann et al. (2009) is recommended for rearing X. glabratus in vitro.

Configurational Assignments of Conformationally Restricted Bis-Monoterpene Hydroquinones: Utility in Exploration of Endangered Plants

Endangered plant species are a prominent resource for new chemistry. Lindera melissifolia is native to the Southeastern U.S. and scarcely populates the edges of lakes and ponds. Two meroterpenoids, melissifolianes A (1) and B (2) were purified and the 2-D structures elucidated using NMR and HRESIMS. The relative configuration of 1 was established employing the combination of NOE-based distance restraints and the comparisons of experimental and calculated coupling constants. The comparison of calculated and experimental ECD established the absolute configuration of 1. The relative configuration of a racemic mixture, melissifoliane B (2) was assigned utilizing J-based analysis combined with quantum mechanics and NMR techniques.

Lindera melissifolia responses to flood durations and light regimes suggest strategies for recovery and conservation

Passive management to preserve endangered plant species involves measures to avoid anthropogenic disturbance of natural populations, but this approach may not sustain plants that require disturbance-maintained habitats. Active management is often necessary to maintain existing habitats or provide new habitats for endangered species recovery. Our objective was to examine the effects of two disturbances in floodplain forests, soil flooding and light availability, on survival, stem length, stem diameter and ramet production of endangered Lindera melissifolia (Walt.) Blume. We used a water impoundment facility to control the timing and duration of flooding (0, 45 or 90 days) and shade houses to vary light availability (70, 63 or 5 % ambient light). Hydroperiod had little direct effect on steckling survival, stem length growth and stem diameter growth, supporting indications that soil flooding may be important for reduction of interspecific competition in L. melissifolia habitat. Greater ramet production by stecklings receiving no soil flooding likely resulted from longer periods of favorable soil conditions during each growing season. Positive stem length growth and stem diameter growth under all light levels demonstrates the plasticity of this species to acclimate to a range of light environments, though, greatest survival and stem length growth occurred when L. melissifolia received 37 % light, and stem diameter growth was greatest beneath 70 % light. Further, female clones produced more ramets as light availability increased. These results indicate that passive management absent natural disturbance could jeopardize sustainability of extant L. melissifolia populations, and this species would respond favorably to active management practices that create canopy openings to increase understory light availability.

Configurational assignments of conformationally restricted bis-monoterpene hydroquinones: Utility in exploration of endangered plants

BackgroundEndangered plant species are an important resource for new chemistry. Lindera melissifolia is native to the Southeastern U.S. and scarcely populates the edges of lakes and ponds. Quantum mechanics (QM) used in combination with NMR/ECD is a powerful tool for the assignment of absolute configuration in lieu of X-ray crystallography. MethodsThe EtOAc extract of L. melissifolia was subject to chromatographic analysis by VLC and HPLC. Spin–spin coupling constant (SSCC) were calculated using DFT at the MPW1PW91/6-31G(d,p) level for all staggered rotamers. ECD calculations employed Amber* force fields followed by PM6 semi-empirical optimizations. Hetero- and homo-nuclear coupling constants were extracted from 1D 1H, E.COSY and HETLOC experiments. ResultsTwo meroterpenoids, melissifolianes A (1) and B (2) were purified and their 2-D structures elucidated using NMR and HRESIMS. The relative configuration of 1 was established using the combination of NOE-based distance restraints and the comparisons of experimental and calculated SSCCs. The comparison of calculated and experimental ECD assigned the absolute configuration of 1. The relative configuration of a racemic mixture, melissifoliane B (2) was established utilizing J-based analysis combined with QM and NMR techniques.Conclusion Our study of the Lindera melissifolia metabolome exemplifies how new chemistry remains undiscovered among the numerous endangered plant species and demonstrates how analysis by ECD and NMR combined with various QM calculations is a sensible approach to support the stereochemical assignment of molecules with conformationally restricted conformations. General significanceQM–NMR/ECD combined approaches are of utility for unambiguous assignment of 3-D structures, especially with limited plant material and when a molecule is conformationally restricted. Conservation of an endangered plant species can be supported through identification of its new chemistry and utilization of that chemistry for commercial purposes.

Extensive clonal growth and biased sex ratios of an endangered dioecious shrub, Lindera melissifolia (Walt) Blume (Lauraceae)1

Plant life history traits like clonal growth and dioecy can complicate endangered species conservation because of the potential for remnant populations to contain few genetically different individuals or a single sex. In this study, we used 11 microsatellite (SSR) markers to characterize fine-scale genetic structure of the endangered dioecious perennial Lindera melissifolia (pondberry) growing in seasonally isolated wetlands across the southern Atlantic Coastal Plain. We found fine-scale genetic structures consistent with extensive clonal growth in all sites. Of the 508 stems sampled across 11 sites, we found 67 genetic individuals (genets), of which 94% were site specific and 39% were represented by a single stem. Individual sites contained from 1 to 16 genets. Spatial genetic analyses showed limited intermingling among different genets within sites, which is consistent with a phalanx clonal growth form. Nine of the eleven sites had biased sex ratios, with six male and three female biased sites. Given our observations of extensive clonal growth, few genetic individuals, and biased sex ratios, we conclude that simple stem counts of this clonal perennial dioecious shrub will grossly overestimate the number of genetic individuals in these remnant southern Atlantic Coastal Plain sites. In order to promote self-sustaining sexually reproducing pondberry populations, as outlined in the pondberry recovery plan, natural areas managers may want to consider introducing unrelated and underrepresented gender plants into sites with few genets or biased sex ratios.

Natural product studies of U.S. endangered plants: Volatile components of Lindera melissifolia (Lauraceae) repel mosquitoes and ticks

The number of endangered plant species in the U.S. is significant, yet studies aimed towards utilizing these plants are limited. Ticks and mosquitoes are vectors of significant pathogenic diseases of humans. Repellents are critical means of personal protection against biting arthropods and disease transmission. The essential oil and solvent extracts from Lindera melissifolia (Walt.) Blume (Lauraceae) (pondberry) drupes were gathered and analyzed by GC and GC–MS. The essential oil obtained from this endangered plant showed a significant dose dependent repellency of ticks and a moderate mosquito repellent effect while the subsequent hexanes extract was completely ineffective. Fractional freezing enriched the tick repellent components of the essential oil. Several known tick repellent components were recognized by the GC–MS comparison of the resulting fractions and β-caryophyllene, α-humulene, germacrene D and β-elemene warrant evaluations for tick repellency. Identifying pondberry as a potential renewable source for a broad spectrum repellent supports efforts to conserve similar U.S. endangered or threatened plant species.

Susceptibility to Laurel Wilt and Disease Incidence in Two Rare Plant Species, Pondberry and Pondspice.

Laurel wilt, caused by Raffaelea lauricola, has been responsible for extensive losses of redbay (Persea borbonia) in South Carolina and Georgia since 2003. Symptoms of the disease have been noted in other species of the Lauraceae such as the federally endangered pondberry (Lindera melissifolia) and the threatened pondspice (Litsea aestivalis). Pondberry and pondspice seedlings were inoculated with R. lauricola from redbay, and both species proved highly susceptible to laurel wilt. Field assessments found substantial mortality of pondberry and pondspice, but in many cases the losses were not attributable to laurel wilt. R. lauricola was isolated from only 4 of 29 symptomatic pondberry plants at one site, but the fungus was not recovered from three plants at another site. R. lauricola was isolated from one of two symptomatic pondspice plants at one site, and from five of 11 plants at another site, but not from any plant at a third site. Insect bore holes, similar to those produced by Xyleborus glabratus (the vector of laurel wilt), were found in some pondberry and pondspice stems, but adults were not found. Damage caused by Xylosandrus compactus was found in pondberry stems, but this ambrosia beetle does not appear to be a vector of R. lauricola. Xyleborinus saxeseni adults were found in a dying pondspice with laurel wilt, and R. lauricola was recovered from two of three adults. Isolates of R. lauricola from pondberry, pondspice, and X. saxeseni had rDNA sequences that were identical to previously characterized isolates, and inoculation tests confirmed that they were pathogenic to redbay. Because pondberry and pondspice tend to be shrubby plants with small stem diameters, these species may not be frequently attacked by X. glabratus unless in close proximity to larger diameter redbay.

Seed ecology of Lindera melissifolia (Lauraceae) as it relates to rarity of the species1

The seed ecology of the federally endangered shrub, Lindera melissifolia was investigated to determine if this aspect of the species life history contributes to the rarity of the species. Lindera melissifolia has the capacity to form a short-lived (two growing seasons) persistent soil seed bank if fruit pulp remains on seeds following dispersal and subsequent winter flooding occurs. Seeds, both with or without pulp (i.e., mesocarp and exocarp), exhibited tolerance to submergence, but were not hydrochorous. Following 6–12 weeks cold stratification (5° or 5/1° C) or submersion in cold water (5/1° C) for 12 weeks, ≥ 63% of seeds germinated when incubated in light and at temperatures of 35/20° and 30/20° C. When incubated in darkness, 100% of seeds germinated following 6 weeks of cold stratification. Giberrelic acid was moderately effective in breaking dormancy. Collectively, our results indicate that seeds of L. melissifolia have nondeep physiological dormancy. Aspects of the seed ecology of L. melissifolia that may contribute to continued rarity of the species include absence of a long-term persistent soil seed bank, no obvious mechanism of long-distance dispersal, and late season germination that prevents seedling growth to a sufficient size for survival prior to cold temperatures and flooding.

Development and plasticity of endangered shrubLindera melissifolia(Lauraceae) seedlings under contrasting light regimes

AbstractLindera melissifolia(Walt.) Blume seedlings were raised in a growth chamber to determine the effects of light availability on shoot growth pattern, and basic leaf and stem growth.Lindera melissifoliaseedlings exhibited a sympodial shoot growth pattern for 3 months following emergence from the soil medium, but this pattern was characterized by a reduction in leaf blade area approximately 30 days after emergence, followed by increases in leaf blade area. Seedlings receiving low light were 76% taller than seedlings receiving high light. Seedlings receiving low light also had larger leaf blade dimensions, blade area, seedling leaf area, and greater mass. Seedlings raised in high light had a greater proportional distribution of biomass in the roots, suggesting possible water stress from greater vapor pressure deficits. Furthermore, these seedlings displayed sharp angles of blade inclination and blade folding – acclimation that reduces exposure to light and subsequent higher leaf temperatures in open environments. These differences in morphological response to light resulted in high phenotypic variability inL. melissifoliaseedlings.Lindera melissifoliaseedling development showed a brief period of phenotypic plasticity, followed by ontogenetic plasticity. The short period of phenotypic plasticity may, however, have profound ecological implications for the conservation and recovery of this federally endangered shrub. Further experimentation should take into account the development of ontogenetic standards for comparisons of plant traits in addition to temporal standards.