Seed Cryopreservation and Germination of Rhus glabra and the Critically Endangered Species Rhus michauxii

Rhus michauxii is a perennial rhizomatous shrub native to the southeastern United States that is found mainly in sunny, dry, open rocky or sandy woodlands. Moreover, it is found on ridges or river bluffs in the inner coastal plane and lower piedmont of Virginia, Georgia, and the Carolinas. Habitat conversion to agriculture, suppression of fires, and low reproduction have caused R. michauxii to become rare and it is now federally listed as threatened. Methods are needed to multiply and conserve R. michauxii. Protocols were developed for seed cryopreservation, in vitro germination, and micropropagation for R. glabra and R. michauxii. Seed scarification in concentrated sulfuric acid for 6 h and germination on ½ MS medium resulted in germination up to 96% for control and cryopreserved seeds of R. glabra and 70 and 40% for control and cryopreserved seeds of R. michauxii. Shortly after germination in vitro, young seedlings were established in a greenhouse potting mix providing new plants from the endemic Georgia R. michauxii populations. Several of the findings meet goals within the R. michauxii recovery plan by providing methods for sexual and asexual multiplication and long-term seed storage under cryogenic conditions. The protocols developed will assist in the safeguarding and conservation of dwindling natural R. michauxii populations.

First record of Hylaeus pictipes Nylander, 1852 (Hymenoptera, Colletidae) in Virginia, United States of America

Insect surveys of developed areas can provide important new species records as these areas are often under-surveyed and assumed to have low biodiversity. These surveys are of increasing importance as fragmentation and habitat conversion further alters the biosphere. We report a new state species record from Virginia: five Hylaeus (Paraprosopis) pictipes Nylander, 1852 (Hymenoptera, Colletidae). Field surveys in Richmond and the surrounding areas found this species from 28 April to 5 August 2019. This is the furthest south H. pictipes has been recorded on the east coast of the USA.

The two extinctions of the Carolina Parakeet Conuropsis carolinensis

Summary Due to climate change and habitat conversion, estimates of the resulting levels of species extinction over the next century are alarming. Devising conservation solutions will require many different approaches, including examining the extinction processes of recently extinct species. Given that parrots are one of the most threatened groups of birds, information regarding parrot extinction is pressing. While most recent parrot extinctions have been island endemics, the Carolina Parakeet Conuropsis carolinensis had an 18th-century range covering nearly half of the present-day United States, yet mostly disappeared by the end of the 19th century. Despite a great deal of speculation, the major cause of its extinction remains unknown. Establishing the date when a species went extinct is one of the first steps in determining what caused their extinction. While there have been estimates of their extinction date, these analyses used a limited dataset and did not include observational data. We used a recently published, extensive dataset of Carolina Parakeet specimens and observations combined with a Bayesian extinction estimating model to determine the most likely extinction dates. By considering each of the two subspecies independently, we found that they went extinct ˜30 years apart: the western subspecies C. c. ludovicianus going extinct around 1914 and the eastern subspecies C. c. carolinensis either in the late 1930s or mid-1940s. Had we only considered all observations together, this pattern would have been obscured, possibly missing a major clue in solving the mystery of the parakeet’s extinction. Since the Carolina Parakeet was a wide-ranging species that went extinct during a period of rapid agricultural and industrial expansion, conditions that mirror those occurring in many parts of the world where parrot diversity is highest, any progress we make in unraveling the mystery of their disappearance may be vital to modern conservation efforts.

Effects of Habitat Conversion on Ant Functional Groups: A Global Review

Conversion of natural to anthropogenic environments affects biodiversity, and the understanding of these impacts may be improved by assessing how different functional groups respond to such land conversion. We studied land conversion impacts on ant functional groups, as ants are ecologically important and respond well to various environmental changes. We hypothesized that conversion of natural to anthropogenic environments modifies the composition of functional groups, fostering generalist and opportunistic groups over specialist ones, with more responses of this type in tropical than in temperate regions. We recovered 412 papers from ISI Web of Science, of which we selected 17 studies, published between 1993 and 2018, that addressed our study’s question. We assessed whether each functional group responded positively or negatively to conversion of natural habitat into anthropogenic land uses and used Monte Carlo tests to assess significance. Ants were affected by natural habitat conversion into monoculture and polyculture and by the conversion of savannas and of tropical and subtropical forests. Land conversion affected six of the 13 functional groups assessed here. In the temperate zone, cryptic species, predators, subordinate Camponotini, cold-climate specialists and tropical-climate specialists were impaired, whereas hot-climate specialists were favored. In the tropics, land conversion negatively impacted fungus-growers and predators. In both climatic zones, several functional groups, mainly those with broad ecological niches, did not respond to land conversion. Our results corroborate that land conversion effects vary among ant functional groups and indicate that the ant fauna of temperate ecosystems may be more susceptible than that of tropical regions.

Financial analysis of converting rural lawns to pollinator habitat in the U.S. Corn Belt

Conservation efforts in rural landscapes seek to improve the multifunctional nature of land uses for people and the biotic communities that support them. In these environments, existing turf grass lawns mowed routinely thorough the summer presents an opportunity where changes in management from intensively managed monocultures toward diverse native perennial vegetation can stack environmental benefits by improving soil health, water quality, and wildlife habitat. Conversion of lawns to pollinator habitat can help achieve continental goals of reversing declines in high-profile species like monarch butterflies Danaus plexippus and native bees. Here, we present a study that examines the financial implications for landowners and managers considering conversion of lawns to pollinator habitat in rural landscapes. We examined financial factors over a 10-year management horizon in three unique scenarios with a range of expenses; self-maintenance of lawns, contracted maintenance of lawns, and establishment and management of pollinator habitat. Our analyses indicate conversion to pollinator habitat was appreciably less expensive ($54-$167/acre/year) than continued self-care ($637-$1,007/acre/year) or contracted care ($326-$1034/acre/year) of lawns over a 10-year period. These results establish the financial benefits for landowners or land managers considering an alternative management paradigm of existing lawns. These financial benefits complement existing literature demonstrating multiple ecological benefits of diverse native perennial vegetation.

Spatiotemporal patterns in Golden-cheeked Warbler breeding habitat quality and quantity

The Golden-cheeked Warbler, Setophaga chrysoparia, is a migratory songbird listed as endangered under the federal Endangered Species Act that breeds exclusively in central Texas and is heavily impacted by habitat conversion. The species relies on mixed Ashe-juniper and oak woodlands for nest-building and shelter during spring and early summer months. Using land cover data spanning the last 25 years, we conducted a geospatial analysis to quantify changes and identify shifts in breeding habitat quantity and quality. Since 1985, 13% of all forests within the warbler's breeding range were disturbed, with greater incidences near San Antonio (32%) and Austin (24%) metropolitan areas. Additionally, there was a 45% decrease in high-quality habitat (i.e., intact mixed or evergreen core forests) and a decrease in patch size. Habitats within protected areas saw a less sharp decline in habitat quality and large increases in warbler sightings, but these only represent 10% of all highest-quality habitat in the breeding range. Drastic declines in habitat quality suggest that generalized metrics of conversion may underestimate true habitat loss as degradation may impact the ecological viability of remaining forests for warbler nesting. Further evidence suggests that the few protected areas within the Texas range continue to play a significant role in warbler breeding. This information will assist researchers and managers prioritizing conservation action and will inform upcoming species status determinations.

Salted roads lead to edema and reduced locomotor function in wood frogs

Human activities have caused massive losses of natural populations across the globe. Like many groups, amphibians have experienced substantial declines worldwide, driven by environmental changes such as habitat conversion, pollution, and disease emergence. Each of these drivers is often found in close association with the presence of roads. Here we report a novel consequence of roads affecting an amphibian native to much of North America, the wood frog (Rana sylvatica). Across 38 populations distributed from southern to central New England, we found that adult wood frogs living adjacent to roads had higher incidence and severity of edema (bloating caused by fluid accumulation) during the breeding season than frogs living away from the influence of roads. This effect was best explained by increased conductivity of breeding ponds, caused by runoff pollution from road salt used for de-icing. Edema severity was negatively correlated with locomotor performance in more northerly populations. Interestingly, northern populations experience more intense winters, which tends to result in more de-icing salt runoff and increased energetic demands associated with overwintering cryoprotection needs. Thus, this emerging consequence of roads appears to impose potential fitness costs associated with locomotion, and these effects might be most impactful on populations living in regions where de-icing is most intense.

The Regenerative Potential of Managed Calluna Heathlands—Revealing Optical and Structural Traits for Predicting Recovery Dynamics

The potential of vegetation recovery through resprouting of plant tissue from buds after the removal of aboveground biomass is a key resilience strategy for populations under abrupt environmental change. Resprouting leads to fast regeneration, particularly after the implementation of mechanical mowing as part of active management for promoting open habitats. We investigated whether recovery dynamics of resprouting and the threat of habitat conversion can be predicted by optical and structural stand traits derived from drone imagery in a protected heathland area. We conducted multivariate regression for variable selection and random forest regression for predictive modeling using 50 spectral predictors, textural features and height parameters to quantify Calluna resprouting and grass invasion in before-mowing images that were related to vegetation recovery in after-mowing imagery. The study reveals that Calluna resprouting can be explained by significant optical predictors of mainly green reflectance in parental individuals. In contrast, grass encroachment is identified by structural canopy properties that indicate before-mowing grass interpenetration as starting points for after-mowing dispersal. We prove the concept of trait propagation through time providing significant derivates for a low-cost drone system. It can be utilized to build drone-based decision support systems for evaluating consequences and requirements of habitat management practice.

Panthera Onca Corridors: A Spatially Explicit Analysis of Habitat Change Drivers and Potential Conservation Areas in the Bajo Magdalena, Colombia

The distribution range of Jaguar (Panthera onca) is being reduced due to multi-scale habitat conversion, intensive hunting, illegal trafficking, habitat fragmentation, and the construction of highways and other infrastructure. Because of the decrease in population, this species’ listing has changed from vulnerable to a threatened category. Due to the ecological importance of this species, organizations like Red Colombiana de Seguimiento de Fauna Atropellada have proposed the establishment of wildlife corridors. But little is known as to recognize the driving forces in these habitat changes and where these corridors should be established. To address this lack of information, we determined the spatial extent to which the current distribution and access to P. onca habitat is being driven by deforestation, armed conflict, agriculture expansion, urbanization and the construction of highways in the Bajo Magdalena area of Colombia. We then identified potential areas for proposing conservation corridors. To do this, we used available geospatial information on P. onca distribution in the Corporación Autónoma Regional areas in the municipalities of Puerto Salgar, Caparrapí and Guaduas, as well as transportation network, administrative unit, and deforestation data from 2010 to 2018. We also calculated habitat distances to population centers and the distribution of P. onca relative to roads. Our findings suggest that urban population and highways affect 83 % of the total area of its distribution; deforestation increased by 47.9 km2 in the 105.24 km2 study area with 5.6 km2 alone left as P. onca habitat. We concluded that conservation initiatives must be implemented inside P. onca’s distributional range and buffer zones. Urbanization and the construction of highways were highly influential variables associated with the loss of P. onca habitat. Further, we propose that precautions along the principal road that connects Puerto Salgar and Guaduas should be taken into consideration to maintain the genetic flow and movement of the P. onca population as it affects 87 km of this proposed corridor.