Myla Aronson | Rutgers, The State University of New Jersey (original) (raw)

Papers by Myla Aronson

Ecology, 2016

The majority of humanity now lives in cities or towns, with this proportion expected to continue ... more The majority of humanity now lives in cities or towns, with this proportion expected to continue increasing for the foreseeable future. As novel ecosystems, urban areas offer an ideal opportunity to examine multi-scalar processes involved in community assembly as well Accepted Article This article is protected by copyright. All rights reserved. as the role of human activities in modulating environmental drivers of biodiversity. Although ecologists have made great strides in recent decades at documenting ecological relationships in urban areas, much remains unknown, and we still need to identify the major ecological factors, aside from habitat loss, behind the persistence or extinction of species and guilds of species in cities. Given this paucity of knowledge, there is an immediate need to facilitate collaborative, interdisciplinary research on the patterns and drivers of biodiversity in cities at multiple spatial scales. In this review, we introduce a new conceptual framework for understanding the filtering processes that mold diversity of urban floras and faunas. We hypothesize that the following hierarchical series of filters influence species distributions in cities: 1) regional climatic and biogeographical factors; 2) human facilitation; 3) urban form and development history; 4) socioeconomic and cultural factors; and 5) species interactions. In addition to these filters, life history and functional traits of species are important in determining community assembly and act at multiple spatial scales. Using these filters as a conceptual framework can help frame future research needed to elucidate processes of community assembly in urban areas. Understanding how humans influence community structure and processes will aid in the management, design, and planning of our cities to best support biodiversity.

Urban Ecosystems, 2014

ABSTRACT The rapid urbanization of the world has significant ecological consequences that shape g... more ABSTRACT The rapid urbanization of the world has significant ecological consequences that shape global biodiversity patterns. The plant communities now common in urban centers may represent new habitats with unique dynamics and the potential for highly modified ecological services. This study, joining extensive spatial and floristic data sets, examined current distribution patterns of non-native and native woody plant species in the New York metropolitan region, USA. We joined the New York Metropolitan Flora (NYMF) database of woody species with GIS data of urban land cover for 297 5 km by 5 km landscape blocks. We tested the relationship between urbanization and native and non-native species richness patterns, the extent of non-native species presence in the urban area, and the change in beta diversity across a gradient of urban land cover. We found that across the urban–rural gradient, native plant species richness decreased and non-native species richness increased with increasing urban land cover. Total richness does not change across the urban–rural gradient. Our analyses show that these patterns are highly correlated with urbanization, but vary across the New Jersey landscape. We also found an increase in beta diversity with urbanization; urban areas are not homogenized in plant species composition compared to rural areas. Here we show a species-rich flora dominated by non-native species which are differentiating the urban flora. These results can help guide appropriate conservation decisions for the maintenance of plant biodiversity in cities.

Background/Question/Methods The greatest cause of degradation to major waterways, such as New Jer... more Background/Question/Methods The greatest cause of degradation to major waterways, such as New Jersey’s Barnegat Bay, is eutrophication. Our research is focused on the riparian zone of the Toms River in New Jersey, with the goal of investigating the role of plant and bacterial communities in filtering excess nitrogen. To accomplish this, we have measured plant and soil microbial community composition at four different sites along the Toms River. At each of the four sites, we surveyed three transects that were parallel, perpendicular and upland from the river. Soil samples were returned to the lab for microbial DNA fingerprinting (terminal restriction fragment length polymorphism- TRFLP). Water and soil chemistry samples were also taken at all four sites. Results/Conclusions Plant diversity varied greatly between sites, however, one of the most common families seen at all sites was Ericaceae. The plant communities within the downstream sites were very different, ranging from Chamaecyp...

ABSTRACT In 1997, Thomas Woltz of Nelson Byrd Woltz Landscape Architects (NBW) began working with... more ABSTRACT In 1997, Thomas Woltz of Nelson Byrd Woltz Landscape Architects (NBW) began working with Seven Ponds Farm in Virginia to restore bio-diversity and natural heritage to this 60 ha cattle farm. Over the past 16 years, Woltz and his team, along with constant collaboration and communication with the land-owner, have turned what was once overgrazed pasture land into a model for restoration of biodiversity and ecological services. We at Ecological Restoration interviewed Thomas Woltz to gain his perspective on the restoration of this agrarian landscape to a functioning grassland/meadow and forest complex in the foothills of the Blue Ridge Mountains. Seven Ponds Farm is privately owned and the owners of the property deeply value nature and the restoration of biodiversity and ecological services for overall health of the landscape and their family. From the beginning, the goal of this landscape transformation was to maximize native biodiversity while restoring a degraded agricultural landscape. Although previous owners used the land for farming income, the new owner is dedicated to Virginia natural heritage and biodiversity. Additionally, Woltz and the property owners wished to use design to reveal the ecological narratives of the landscape. What is most unique about the design are the additional goals of producing knowledge through restoration experimentation and emphasizing the critical importance of ongoing monitoring in the designed landscape. This previously incised stream was subject to nutrient and sediment overload. The construction of small stone spillways created multiple small ponds and facilitated the regrading of the stream while also providing walking paths for access throughout the property. In the beginning, restoration of the farm faced several major landscape issues. First, the farm was heavily grazed by cattle for close to 75 years. This grazing pressure led to limited biodiversity in the open fields, severe erosion of the two distinct watersheds on the property, and prevalence of invasive plant species. Additionally, overabundance of white-tailed deer in the area caused the degradation of ground vegetation and sapling trees in the woodlands of the property, decreasing biodiversity even further. As restoration progressed, other issues appeared, particularly the pressure of invasive plant species on the meadow restorations and the pressures of surrounding suburban development. In order to deal with the eroded waterways and incised streams, Woltz and his team designed small pools at the headwaters of the streams to slow water flow (with the added benefit of providing habitat for amphibians) (Figure 1). They used filtration strips and shrub plantings to stabilize the stream banks. They have also planted native tree species across the property, within highly designed gardens as well as woodlands. Since the beginning of the project, they have planted nearly 10,000 native trees as part of a large reforestation effort, using black fabric mats and plastic tubes to increase early establishment rates by suppressing competing plants and inhibiting deer herbivory. In other areas, large expanses of grasslands have been established where there were once grazing pastures. Constant management of invasive plant species has occurred over the last 16 years by the farm staff using both mechanical and chemical methods of control. Finally, in late 2012, a 2.7 m high deer fence was built surrounding the entire property to reduce the effects of overgrazing by white-tailed deer. It is in the grassland meadows where NBW has incorporated the science of restoration most clearly. The grasslands cover over 12 ha of rolling hills within the property and have winding paths throughout (Figure 2). The paths are laid out in long, gracious curves topographically, allowing visitors to immerse themselves in this big powerful landscape. Woltz feels the paths really allow people to closely experience the meadow (which can reach 2 m high by the end of the growing season), feeling the surrounding landscape. Visitors experience the local changes in diversity as they walk through a topographic and temporal gradient. As guests walk downhill they experience wetter meadows. The temporal gradient is represented by the burn regime of the restorations. Some fields are three years since the last burn, while others were burned that season. The age of the restorations also varies. The meadows have been established in six or seven segments...

ABSTRACT Background/Question/Methods Cities are novel ecosystems characterized by fragmented and ... more ABSTRACT Background/Question/Methods Cities are novel ecosystems characterized by fragmented and disturbed environments, high densities of fabricated structures and impervious surfaces, and elevated levels of certain resources. Globally, these commonalities, in combination with human mediated biotic interchange, may result in the homogenization of species composition among cities. In addition, cities are often located in species rich regions where native species are threatened by habitat loss and species introductions. Given the World’s urban population is growing 1% per-annum on average, a better understanding of the global patterns and drivers of urban biodiversity is necessary for sustainable planning and conservation. We compiled city-wide bird species lists for 54 cities and city-wide floras of spontaneously established vascular plants for 110 cities. The lists encompass 36 countries on six continents and represents the largest compilation of urban biodiversity data to date. We examined patterns of species diversity within and among cities and their environmental and anthropogenic correlates. Results/Conclusions Bird and plant species richness (median: birds = 112.5, plants = 762) and the number of non-native species (median: birds = 3.5, plants = 213) differed broadly among cities with cities containing, on average, more native species. The number of species in each city was predicted primarily by the physical features of the city related to population size and land-cover, with the species-area relationship playing a dominant role. The proportion of non-native plants in each city was predicted by multiple factors suggesting their prevalence was not determined exclusively by human activities. Globally, the compositions of plant and bird species were highly dissimilar among cities. Within regions, the composition of non-native plants and birds were more similar among cities, particularly within regions outside of Europe. Non-native plants identified as European archaeophytes (introduced into Europe prior to ad 1500) and species of plants and birds identified as global invaders were shared more broadly among cities, particularly within regions outside of Europe. Younger cities further from the equator with close climatic and cultural associations to Europe tended to have more similar compositions of plant species. For birds, compositional patterns did not differ along similar gradients, likely due to the presence of a limited number of identical non-native bird species. Despite worldwide biodiversity loss, cities currently retain their regional biological identities, with Europe playing a historical role as a source of urban adapted species. Urban biodiversity can play an important role supporting conservation, restoration, and education initiatives in a rapidly urbanizing world.

Proceedings of the Royal Society B: Biological Sciences, 2014

Supplementary data tml

Natural Areas Journal, 2011

Global Ecology and Biogeography, 2014

Aim Cities represent an ideal study system for assessing how intensive land-use change and biotic... more Aim Cities represent an ideal study system for assessing how intensive land-use change and biotic interchange have altered beta diversity at broad geographic extents. Here we test the hypothesis that floras in cities located in disparate regions of the globe are being homogenized by species classified as invasive (naturalized species that have spread over a large area) or as a European archaeophyte (species introduced into Europe before ad 1500 from the Mediterranean Basin). We also test the prediction that the global influences of European activities (colonization, agriculture, commerce) have supported this outcome.

Biological Invasions, 2008

Ecosystem engineers play a large role in physically structuring the ecosystem in which they are e... more Ecosystem engineers play a large role in physically structuring the ecosystem in which they are embedded. The focus of much of the research surrounding these species is to document the impacts of a single engineer on community composition and ecosystem processes. However, most ecosystems harbor multiple engineering species that interact in complex ways and rarely have the dynamics of such species been fully investigated. We look at how two ecosystem engineers, the white-tailed deer (Odocoileus virginianus) and the invasive plant Japanese stilt grass (Microstegium vimineum), interact to completely alter the structure and composition of the subcanopy within northern deciduous forests. This interaction has wide-ranging repercussions on forest food webs which we explore through a case study of breeding woodland birds in the state of New Jersey, USA. We show that the guilds of birds that rely on the subcanopy have experienced greater declines from 1980 to 2005 than birds that specialize on the intact upper canopy of impacted forests. This dynamic is not restricted to immediate temporal effects and may act to derail the long-term successional pathway of northern deciduous forests. It is no longer prudent to set aside tracts of forest and expect them to retain their native biodiversity without active management.

Biological Invasions, 2007

The spread of alien plant species is a critical ecological event worldwide, but the forces that c... more The spread of alien plant species is a critical ecological event worldwide, but the forces that control this spread are not well documented. Alien plant species are well known to disrupt ecological services of native ecosystems, change the composition of native habitats, and often lead to the extirpation of native flora and fauna. Here, we report on life history patterns of plant species with rapidly spreading and declining ranges in North America's major urban region. We tested for differences in life history traits between the 466 native and alien woody flora of the New York metropolitan area. We also examined the relationship between life history traits and change in distribution in the New York metropolitan area between 1900 and 2000. Native and alien species of the New York metropolitan area differ with respect to pollination vector and breeding system. However, pollination vector and breeding system are not associated with success, defined here as increasing range spread in the urban environment; instead, fruit type (dispersal), life form and origin are important determinants of success. Alien species that are deciduous trees, shrubs or vines with fleshy fruit are the most successful in increasing their distribution in this urban landscape. Newly introduced species with these characteristics are expected to have a better chance at establishing in similar urban landscapes and should be targets for intensive management. The ability to predict which alien species will become invasive is also a valuable tool for the prevention of invasions by newly introduced plant species.

ABSTRACT Background/Question/Methods Urbanization of watersheds leads to unique situations in whi... more ABSTRACT Background/Question/Methods Urbanization of watersheds leads to unique situations in which ecological and informational flow can be impeded or altered by physical and jurisdictional barriers. We studied the ecological and social connectivity of the Rahway River Watershed, New Jersey. The Rahway River watershed encompasses an urban to rural gradient and a diverse socioeconomic gradient. The watershed lacks a formal institutionalized collaborative watershed management program. To study social connectivity, we studied interorganizational ties or connections created to share information or resources or to spur cooperative management. To study ecological connectivity, we examined the stream bank vegetation and seed dispersal along three 2nd order streams located in three counties of NJ. Along each stream we sampled four river zones (above a dam, directly below the dam, above a concrete embankment, below a concrete embankment). Once a month at each zone we randomly collected four leaf litter piles, cold stratified for two months, and germinated seeds on sterile soil in the greenhouse. We identified all individuals to species where possible. Vegetation surveys were performed at each zone. We compared plant community structure between litter piles and field vegetation surveys to access movement of seeds along the river. Results/Conclusions Preliminary results show non-native invasive plant species such as Artemisia vulgaris and Polygonum cuspidatum promote the greatest connectivity among sites along streams in the Rahway River watershed. These are also the most common herbaceous species on the banks. Stream banks supporting 153 plant species and 45 species were found in the April 2011 litter collection. Beta-diversity is greatest above dams and least below, suggesting dams homogenize biota downstream, likely by impeding particular species at the dam. Sites above and below concrete embankments have similar biota, indicating these embankments may not filter biota due to the fast-moving currents. The watershed interorganizational network primarily includes municipal governments and is sparse with large gaps. There is a watershed organization with ties to most of the actors, but because of lack of support, this organization has not been able to act as a broker for cooperation across jurisdictions. County governments attempt some coordination along the river system, but collaborative watershed management as a whole does not exist. In order to promote social connectivity and collaborative watershed management of the Rahway River watershed, there is a need for a watershed organization to coordinate the municipality, county, and state governments responsible for managing the river system.