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The conservation of a rare species requires an understanding of its habitat requirements, including its response to different light levels. Accordingly, we conducted a study of the light requirements of Pycnanthemum verticillatum var. verticillatum, a New York State S1S2-Endangered perennial forb found on Staten Island, Richmond County, NY. Much of its present habitat in this urban county is along disturbed roadsides and is undergoing increased shading due to woody encroachment. We grew plants in full sunlight (no shade cloth), medium sunlight (30% shade cloth), and low sunlight (60% shade cloth), and measured their growth, reproductive, and morphological responses. Plants were largest and most likely to produce flowers in the full and medium sunlight treatments. Plants exhibited typical shade-avoidant responses such as stem elongation and increased secondary ramet production in the low sunlight treatment. We conclude that Pycnanthemum verticillatum var. verticillatum may survive in deep shade, but partial and full sun result in more vigorous growth and reproduction. Canopy thinning to maintain no more than 30–50% shade is necessary for the plants to thrive. Managing for sunny habitats, such as meadows and open-canopy forests, would have broad conservation benefits for this species and other native plants that require high-light environments in the region. [ABSTRACT FROM AUTHOR]

Understanding the structure and function of urban landscapes requires integrating social and ecological research. Here, we integrate parallel social and ecological assessments of natural areas within New York City. We examined social data (from a rapid assessment of park use and meaning, collected at a park zone level) alongside ecological data (from a plot-based assessment of forest structure and diversity). In-depth interviews with researchers and managers (n = 11) involved with the social and ecological assessments revealed commonly-held values considered critical for integration, including clear communication, openness, trust, and shared goals and also identified barriers to the integration process, including the scales at which each dataset was collected. We applied an informed, shared problem framing to investigate the relationships between visitor use and ecological condition in urban natural areas. We began with fuzzy cognitive modeling, where researchers developed models of defining a "healthy urban forest." We then developed two social-ecological typologies to examine the integrated dataset in relation to how visitors may affect or perceive ecological health and threat. Typologies identify NYC natural areas where social indicators (number of visitors, diversity of park use motivations) are either high or low and ecological condition is either high or low. Examination of these typologies led to exploring correlations between social and ecological variables, to team discussions, and to developing new research questions. We conclude this paper with a discussion of tradeoffs of this type of emergent, integrative approach to social-ecological synthesis research. [ABSTRACT FROM AUTHOR]

Creating, restoring, and sustaining forests in urban areas are complicated by habitat fragmentation, invasive species, and degraded soils. Although there is some research on the outcomes of urban reforestation plantings during the first 5 years, there is little research on longer term outcomes. Here, we compare the successional trajectories of restored and unrestored forest sites 20 years after initiating restoration. The sites are located within the Rodman's Neck area of Pelham Bay Park, in the northeast corner of the Bronx in New York City ( NYC), U.S.A. Compared with unrestored sites, we saw improvements in species diversity, greater forest structure complexity, and evidence of the regeneration and retention of native tree species in restored sites. In addition, we found differences in restoration outcomes depending on the level of intervention: clearing exotic shrubs and vines and planting native trees and shrubs improved tree diversity and canopy closure to a greater extent than clearing exotics alone, and the mechanical removal of invasive plants after the native plantings further improved some measures of restoration, such as tree species diversity and native tree regeneration. The results of this study suggest that the goal of a sustainable forest ecosystem dominated by native trees and other plant species may not be achievable without continued human intervention on site. In addition, these results indicate that the restoration approach adopted by NYC's reforestation practitioners is moving the site toward a more desirable vegetative community dominated by native species. [ABSTRACT FROM AUTHOR]

Forests are vital components of the urban landscape because they provide ecosystem services such as carbon sequestration, storm-water mitigation, and air-quality improvement. To enhance these services, cities are investing in programs to create urban forests. A major unknown, however, is whether planted trees will grow into the mature, closed-canopied forest on which ecosystem service provision depends. We assessed the influence of biotic and abiotic land management on planted tree performance as part of urban forest restoration in New York City, U.S.A. Biotic treatments were designed to improve tree growth, with the expectation that higher tree species composition (six vs. two) and greater stand complexity (with shrubs vs. without) would facilitate tree performance. Similarly, the abiotic treatment (compost amendment vs. without) was expected to increase tree performance by improving soil conditions. Growth and survival was measured for approximately 1,300 native saplings across three growing seasons. The biotic and abiotic treatments significantly improved tree performance, where shrub presence increased tree height for five of the six tree species, and compost increased basal area and stem volume of all species. Species-specific responses, however, highlighted the difficulty of achieving rapid growth with limited mortality. Pioneer species had the highest growth in stem volume over 3 years (up to 3,500%), but also the highest mortality (up to 40%). Mid-successional species had lower mortality (<16%), but also the slowest growth in volume (approximately 500% in volume). Our results suggest that there will be trade-offs between optimizing tree growth versus survival when implementing urban tree planting initiatives. [ABSTRACT FROM AUTHOR]