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Biology subjects

Yang, L. H.

Publications and source records attributed to Yang, L. H..

4 recordsLinked to original sources

Moisture and competition constrain ephemeral resource quality for burying beetle reproduction

Shifts in abiotic factors such as temperature and moisture can change the availability of resources, especially under climate change. Both abiotic and biotic drivers can have profound, rapid effects on species distribution, survival, and reproduction. Little is known about how abiotic factors affect the availability of ephemeral resources. Burying beetles (Nicrophorus spp.) are specialist users of ephemeral resources, as their reproduction requires locating, defending, and burying a small carcass. Environmental moisture, such as coastal fog, could change how quickly carcasses dry out. We tested the role of carcass moisture and interspecific competition with a generalist scavenger, Heterosilpha spp., on reproduction by placing pairs of Nicrophorus guttula in field chambers with fresh and experimentally dehydrated mouse carcasses. Pairs that were given fresh mouse carcasses were more likely to carry out reproductive behaviors and produce viable offspring than pairs that were given a partially dehydrated mouse. For those pairs that reproduced, competition limited the number of offspring. These results indicate that shifts in abiotic factors under climate change, along with biotic factors like competition, can reduce the availability of ephemeral resource patches for consumers.

ecology↗

Low-troposphere microbial communities differ between dry-air and rainfall but do not show strong seasonal patterns in Metro Atlanta, Southeast USA

The composition and seasonal patterns of airborne bacterial and fungal communities and how these are affected by atmospheric conditions (e.g., dry vs. rain), origin of air masses, and presence of air pollutants remain understudied, despite their obvious importance for public health. To provide insights into these questions, monthly dry air and rain samples were collected at the Environmental Science and Technology building rooftop on Georgia Techs campus (Metro Atlanta) between June 2017 and November 2019. The sampling included the remnants of Hurricane Irma and a Saharan dust event in 2020. Amplicon sequencing of the V4 region of the 16S rRNA gene and the fungal nuclear ribosomal internal transcribed spacer (ITS) region showed that spore-forming bacteria and widespread fungi were enriched in dry samples, while photosynthetic bacteria and wood-decaying fungi were more abundant in rain samples, demonstrating the effect of sample type on bioaerosol composition. Further, higher relative abundance of fungal human pathogens and allergens were identified in the dry-air and Saharan dust samples, including Alternaria alternata and Cladosporium cladosporioides. Bacterial and fungal species richness and composition appeared to be relatively consistent between seasons for both sample types. Accordingly, sample type and seasonality explained [~]14% and [~]8.5% of the microbial diversity between samples, respectively, while presence of air pollutants and three-day back trajectory data were not significant. Collectively, our data indicates that dry air might represent a higher public health risk and provides a reference point for the long-term monitoring of airborne microbial communities in an urban Southeast US setting. ImportanceIn the atmosphere, or in the air we breathe, bioaerosols are always present. Bioaerosols are biological particles (alive or dead) suspended in the air, being bacteria and fungi the most abundant. In addition, bioaerosols can potentially contribute to weather/climate patterns. Although and unfortunately, a clear biodiversity pattern from different atmospheric events (air, rain, snow, etc.) remains to be discovered, especially in urban areas, where bioaerosols can also have implications for public health. The role of airborne microbes and their diversity patterns in the atmosphere constitutes a significant gap in our understanding of their interactions with health, climate, and other ecosystems compared to other environments. Our research provides the first reference point for long-term monitoring of airborne microbial communities in an urban Southeast US setting. This research contributes novel knowledge about public health and insights for integrating biological information into weather and climate prediction models.

microbiology↗

A meta-analysis of single visit pollination effectiveness

Many animals provide essential ecosystem services in the form of plant pollination. A rich literature documents considerable variation in the single visit pollination effectiveness of different plant visitors, but this literature has yet to be comprehensively synthesized. We conducted a hierarchical meta-analysis of 193 studies and extracted 1716 single visit effectiveness (SVE) comparisons for 252 plant species. We paired SVE data with visitation frequency data for 75 of these studies. Given the global dominance of honeybees in pollinator communities, we used these data to ask: 1) Do honeybees (Apis mellifera) and other floral visitors vary in their SVE?; 2) To what extent do plant and pollinator attributes predict the difference in SVE between honeybees and other visitors?; and 3) Is there a correlation between floral visitation frequency and SVE? We found that honeybees were significantly less effective than the most effective non-honeybee pollinator. Although not significantly different, honeybees also tended to be less effective than the mean community effectiveness. Honeybees were less effective as pollinators of crop plants and when compared to birds and other bees. Visitation frequency and pollination effectiveness were positively correlated, but this trend was largely driven by data from communities where honeybees were absent, suggesting that honeybees generally combine high visitation frequency and lower SVE. Our study demonstrates that non-honeybee floral visitors are highly effective pollinators of many crop and non-crop plants. While the high visitation frequency typically displayed by honeybees undoubtably makes them important pollinators, we show that honeybees are slightly less effective than the average pollinator and rarely the most effective pollinator of the plants they visit. As such, honeybees may be imperfect substitutes for the loss of wild pollinators and safeguarding global crop production will benefit from conservation of non-honeybee taxa. Open Research StatementAlthough we are fully committed to data transparency, we are also aware of different research teams working on related meta-analyses. As such, we prefer to wait until our paper is accepted to make data publicly available but are happy to share data upon request. Data will be permanently archived on Figshare following acceptance.

ecology↗

Species-specific, age-varying plant traits affect herbivore growth and survival

Seasonal windows of opportunity represent intervals of time within a year during which organisms have improved prospects of achieving life history aims such as growth or reproduction, and may be commonly structured by temporal variation in abiotic factors, bottom-up factors, and top-down factors. Although seasonal windows of opportunity are likely to be common, few studies have examined the factors that structure seasonal windows of opportunity in time. Here, we experimentally manipulated host plant age in two milkweed species (Asclepias fascicularis and Asclepias speciosa) in order to investigate the role of plant species-specific and plant age-varying traits on the survival and growth of monarch caterpillars (Danaus plexippus). We show that the two plant species showed diverging trajectories of defense traits with increasing age. These species-specific and age-varying host plant traits significantly affected the growth and survival of monarch caterpillars through both resource quality- and resource quantity-based constraints. The effects of plant age on monarch developmental success were comparable to and sometimes larger than those of plant species identity. We conclude that species-specific and age-varying plant traits are likely to be important factors with the potential to structure seasonal windows of opportunity for monarch development, and examine the implications of these findings for both broader patterns in the ontogeny of plant defense traits and the specific ecology of milkweed-monarch interactions in a changing world.

ecology↗