Avian Use of a Bottomland Hardwood Afforestation Site in the Red River Alluvial Valley

Bottomland hardwood forests (BHF) cover about 2.8 million hectares of the original 10 million hectares that once existed in the southeastern United States. These losses have led to an emphasis on afforestation of retired agricultural land. Research was needed to evaluate changes in wildlife communities as these afforested stands progress through succession. To assess the avian community at this 25-year-old afforested BHF, I conducted point count surveys at 28 point locations across seven forest types, six times during the 2016–2018 avian breeding seasons. My research objectives were to determine: (1) if avian density and diversity varied among the dominant forest types that have developed in the research site; and (2) how this BHF compared to mature BHFs of the southeastern United States that were at least 50 years old. Results indicated that avian density varied among forest types showing five statistical groupings, with ranges in density from 22.836 to 6.634 birds/ha among forest types. Avian diversity analyses indicated no significant difference among the seven forest types. Results of comparative analyses indicated that the research site was 68% similar in avian species composition to mature BHFs in the southeastern United States, thus not meeting the goal of 75–85% similarity. My management recommendation is to allow this site to continue on its current path of increasing in similarity as it has shown to have done over the past three breeding seasons, with forest management only taking place if non-native tree species begin to establish in open canopy areas

Avian Use of a Bottomland Hardwood Afforestation Site in the Red River Alluvial Valley

Colby W. Sharp is a Graduate Associate in the School of Biological Sciences at Louisiana Tech University. Heidi L. Adams and William B. Patterson are Assistant Professors in the School of Biological Sciences at Louisiana Tech University

Directed evolution of APEX2 for electron microscopy and proximity labeling

APEX is an engineered peroxidase that functions as an electron microscopy tag and a promiscuous labeling enzyme for live-cell proteomics. Because limited sensitivity precludes applications requiring low APEX expression, we used yeast-display evolution to improve its catalytic efficiency. APEX2 is far more active in cells, enabling the use of electron microscopy to resolve the submitochondrial localization of calcium uptake regulatory protein MICU1. APEX2 also permits superior enrichment of endogenous mitochondrial and endoplasmic reticulum membrane proteins.National Institutes of Health (U.S.) (DP1 OD003961