Clare E Aslan

Northern Arizona University | NAU · Landscape Conservation Initiative

Pollinator losses threaten ecosystems and food security, diminishing gene flow and reproductive output for ecological communities and impacting ecosystem services broadly. For four focal families of bees and butterflies, we constructed over 1400 ensemble species distribution models over two time periods for North America. Models indicated dispropor...

Many contemporary social and ecological challenges in forested ecosystems (climate change, invasive species, wildland-urban interface development, and wildfires) span multiple jurisdictions and are characterized by complex patterns of social and ecological interdependencies. Increasing evidence suggests that interdependent risk can best be addresse...

Protected areas rarely are large enough to encompass the ecological processes that affect them. Accordingly, some authors call for cooperative management of multiple jurisdictions within protected area-centered ecosystems (PACEs) to sustain landscape-scale processes and maximize connectivity and ecosystem service flows. However, over time, differin...

Introduction Ecological conditions at a given site are driven by factors including resource availability, habitat connectivity, and disturbance history. Land managers can influence disturbance history at a site by harvesting resources, creating transportation pathways, introducing new species, and altering the frequency and severity of events such...

Land management decisions have profound impacts on biological communities. Various administrative units are likely to implement different management decisions, with the result that consistent biological patterns that track administrative boundaries may emerge. To assess these relationships, we collected data on land cover, disturbance evidence, and...

Disruption of plant–pollinator interactions by invasive predators is poorly understood but may pose a critical threat for native ecosystems. In a multiyear field experiment in Hawai'i, we suppressed abundances of globally invasive predators and then observed insect visitation to flowers of six native plant species. Three plant species are federally...

Habitat loss and non‐native species are 2 of the most important factors that influence native species persistence and behaviors globally. The insectivorous Hawaiian hoary bat ( Lasiurus semotus ) is the only extant terrestrial mammal native to the Hawaiian Islands. Non‐native invasive insectivore species, which are potential competitors of bats for...

Phenological shifts are a widely studied consequence of climate change. Little is known, however, about certain critical phenological events, nor about mechanistic links between shifts in different life-history stages of the same organism. Among angiosperms, flowering times have been observed to advance with climate change, but, whether fruiting ti...

ContextLarge landscapes exhibit natural heterogeneity. Land management can impose additional variation, altering ecosystem patterns. Habitat characteristics may reflect these management factors, potentially resulting in habitat differences that manifest along jurisdictional boundaries.Objectives We characterized the patchwork of habitats across a c...

Resilience quantifies the ability of a system to remain in or return to its current state following disturbance. Due to inconsistent terminology and usage of resilience frameworks, quantitative resilience studies are challenging, and resilience is often treated as an abstract concept rather than a measurable system characteristic. We used a novel,...

Human‐induced ecological boundaries, or anthropogenic ecotones, may arise where administrative boundaries meet on undeveloped lands. Landscape‐level ecological processes related to factors such as fire, invasive species, grazing, resource extraction, wildlife, and water may be affected due to unique management strategies adopted by each administrat...

As a multi-jurisdictional, non-fire-adapted region, the Sonoran Desert Ecoregion is a complex, social-ecological system faced increasingly with no-analogue conditions. A diversity of management objectives and activities form the socioecological landscape of fire management. Different managers have different objectives, resources, and constraints, a...

Altered fire regimes are among the most destructive consequences of anthropogenic environmental change. Fires have increased in frequency in some regions, and invasion by fire-adapted non-native species has been identified as a major driver of this change, which results in a feedback cycle promoting further spread by the non-native species and dimi...

Despite the importance of seed dispersal as a driving process behind plant community assembly, our understanding of the role of seed dispersal in plant population persistence and spread remains incomplete. As a result, our ability to predict the effects of global change on plant populations is hampered. We need to better understand the fundamental...

There is growing realization that intraspecific variation in seed dispersal can have important ecological and evolutionary consequences. However, we do not have a good understanding of the drivers or causes of intraspecific variation in dispersal, how strong an effect these drivers have, and how widespread they are across dispersal modes. As a firs...

Although dispersal is generally viewed as a crucial determinant for the fitness of any organism, our understanding of its role in the persistence and spread of plant populations remains incomplete. Generalizing and predicting dispersal processes are challenging due to context dependence of seed dispersal, environmental heterogeneity, and interdepen...

Resilience theory aims to understand and predict ecosystem state changes resulting from disturbances. Non-native species are ubiquitous in ecological communities and integrated into many described ecological interaction networks, including mutualisms. By altering the fitness landscape and rewiring species interactions, such network invasion may car...

Abstract Methods to detect and monitor the spread of invasive grasses are critical to avoid ecosystem transformations and large economic costs. The rapid spread of non‐native buffelgrass(Pennisetum ciliare) has intensified fire risk and is replacing fire intolerant native vegetation in the Sonoran Desert of the southwestern US. Coarse‐resolution sa...

Seed dispersal enables plants to reach hospitable germination sites and escape natural enemies. Understanding when and how much seed dispersal matters to plant fitness is critical for understanding plant population and community dynamics. At the same time, the complexity of factors that determine if a seed will be successfully dispersed and subsequ...

Premise of the study: Over one-third of the native flowering plant species in the Hawaiian Islands are listed as federally threatened or endangered. Lack of sufficient pollination could contribute to reductions in populations, reproduction, and genetic diversity among these species but has been little studied. Methods: We used systematic observa...

If an organism becomes rare enough that it no longer participates in certain interspecific interactions, it can be said to have become ecologically extinct, even though it is still present. This form of extinction is much less recognized than global extinctions, although it may have ramifications for ecological community function. Here, we describe...

Changes in fire frequency, size, and severity are driving ecological transformations in many systems. In arid and semi-arid regions that are adapted to fire, long-term fire exclusion by managers leads to declines in fire frequency, altered fire size distribution, and increased proportion of high severity fires. In arid and semi-arid systems where f...

Although resilience thinking is increasingly popular and attractive among restoration practitioners, it carries an abstract quality that hinders effective application. Because resilience and its components are defined differently in social and ecological contexts, individual managers or stakeholders may disagree on the definition of a system’s stat...

The ability to respond to the challenges posed by climate change depends on the adaptive capacities of social and ecological systems. However, the term adaptive capacity is ill defined, and applications often ignore social dimensions. Furthermore, the dominant frameworks conceptualizing adaptive capacity terminate with a vulnerability assessment, w...

Since its inception, conservation biology has inspired thousands of students, spurred the creation of new initiatives, organizations and agencies, and informed conservation efforts worldwide. Nevertheless, global biodiversity loss is accelerating (Butchart et al. 2010), and our field needs to change to keep pace with mounting challenges. Conservati...

The western or European honey bee (Apis mellifera) is the primary managed pollinator in US agricultural systems, and its importance for food production is widely recognized. However, the role of A. mellifera as an introduced species in natural areas is potentially more complicated. The impact of A. mellifera on native insect pollinators can depend...

Premise of research. Biotic interactions have long been considered to be of less importance in structuring desert systems than other ecosystem types, but biotic interactions often play a critical role in meeting the challenges posed by the extreme conditions of desert environments. The Sonoran Desert, in particular, is home to several textbook exam...

Interspecific interactions are important structuring forces in ecological communities. Interactions can be disturbed when species are lost from a community. When interactions result in fitness gains for at least one participating organism, that organism may experience reduced fitness as a result of interaction disturbance. However, many species exh...

Biotic interactions are vital to ecosystem functioning. Interactions among individuals lie at the core of population and community dynamics, and therefore play a central role in the existence and persistence of species. Plants form the food base of most terrestrial ecosystems and are therefore not surprisingly involved in a substantial portion of b...

Mutualisms are important structuring forces in ecological communities, influencing ecosystem functions, diversity, and evolutionary trajectories. New interactions, particularly between native and non-native species, are globally increasing in biotic communities as species introductions accelerate. Positive interactions such as novel mutualisms can...

I studied pollination of the Arizona hedgehog cactus (Echinocereus arizonicus), an endangered plant species occurring in the Superstition Mountains, Arizona, in order to identify the pollinators of the species, determine whether the species is self-incompatible or pollen-limited, and evaluate whether individuals transplanted to make way for habitat...

In situations where native mutualists have become extinct, non-native species may partner with remnant native species. However, non-native mutualists may differ behaviorally from extinct native mutualists. In the case of pollination, novel relationships between natives and non-natives could differ both quantitatively and qualitatively from native–n...

Extinctions beget further extinctions when species lose obligate mutualists, predators, prey, or hosts. Here, we develop a conceptual model of species and community attributes affecting secondary extinction likelihood, incorporating mechanisms that buffer organisms against partner loss. Specialized interactors, including ‘cryptic specialists’ with...

Protected area delineation and conservation action are urgently needed on marine islands, but the potential biodiversity benefits of these activities can be difficult to assess due to lack of species diversity information for lesser known taxa. We used linear mixed effects modeling and simple spatial analyses to investigate whether conservation act...

When a species becomes extinct, its ecological functions are lost as well. Taxon substitution is a controversial approach to restoring such functions via introduction of non-native species known to serve similar functions elsewhere. Due to the possibility of nontarget effects from such introductions, taxon substitution has been proposed and impleme...

Conservation practitioners and scientists are often faced with seemingly intractable problems in which traditional approaches fail. While other sectors (e.g., business) frequently emphasize creative thinking to overcome complex challenges, creativity is rarely identified as an essential skill for conservationists. Yet more creative approaches are u...

Native plant species that have lost their mutualist partners may require non‐native pollinators or seed dispersers to maintain reproduction. When natives are highly specialized, however, it appears doubtful that introduced generalists will partner effectively with them. We used visitation observations and pollination treatments (experimental manipu...

Background/Question/Methods Animal-mediated seed dispersal may enable seeds to escape from predators, parasites, and competitors. It can also boost germination by directing seeds to favorable germination sites and, for some species, removing germination inhibitors. A growing amount of empirical research has found quantifiable decreases in plant r...

As global environmental change accelerates, biodiversity losses can disrupt interspecific interactions. Extinctions of mutualist partners can create "widow" species, which may face reduced ecological fitness. Hypothetically, such mutualism disruptions could have cascading effects on biodiversity by causing additional species coextinctions. However,...

Sources used in quantitative estimates. (DOC)

PRISMA Checklist for systematic review. (DOC)

Vertebrate seed dispersers and pollinators. (XLS)

1. Invasion biologists use two main approaches to evaluate the effects of non-native species (NNS) on diversity of native species (DNS), namely space-for-time and time approaches. These approaches have pitfalls related to lack of controls: the former lacks pre-invasion data, while the latter often lacks data from non-invaded sites. 2. We propose a...

Background/Question/Methods Current global extinction rates, arising from rapid environmental change, generate broadscale disruption in interspecific interactions. Losses of mutualists can erode ecosystem functions, provoke novel numerical and behavioral responses among remnant native species, and further threaten biodiversity. In some settings,...

Extinctions can leave species without mutualist partners and thus potentially reduce their fitness. In cases where non-native species function as mutualists, mutualism disruption associated with species' extinction may be mitigated. To assess the effectiveness of mutualist species with different origins, we conducted a meta-analysis in which we com...

1. Early detection of biological invasions can reduce the costs of control and increase its efficacy. Although much research focuses on the appearance or establishment of new invaders, few studies target the detection of spread from established populations. Managers of natural areas have limited resources; therefore, there is need for efficient met...

Citation: Aslan C, Rejmánek M (2012) Native fruit traits may mediate dispersal competition between native and non-native plants. NeoBiota 12: 1–24. Abstract Seed disperser preferences may mediate the impact of invasive, non-native plant species on their new ecological communities. Significant seed disperser preference for invasives over native spec...

I examined the role of bird dispersal in invasiveness of three non-native plant species in California, USA: Triadica sebifera, Ligustrum lucidum, and Olea europaea. I selected these species because their invasiveness in California is uncertain, but a survey of ornithologists highlighted them as likely bird-dispersed. I quantified bird frugivory of...

Ecological restoration typically focuses on promoting vegetation recovery in degraded habitat or reintroducing endangered animals to enhance their regional or global persistence. Here, we argue that attention should also be devoted to vertebrate reintroductions in overhunted but floristically intact tropical forests in order to prevent insidious re...

Olea europaea (European olive) is invasive in Australia and widely planted in California. Vertebrates, particularly birds, mediate Olea seed dispersal. Fruits are large, but their sizes range widely. We measured fruit widths from 12 study stands in California and constructed esophageal probes in diameters spanning the resulting size range. We then...

Introduced species have the potential to impact processes central to the organization of ecological communities. Although hundreds of nonnative plant species have naturalized in the United States, only a small percentage of these have been studied in their new biotic communities. Their interactions with resident (native and introduced) bird species...

The ecological effects of Chinese tallowtree are well documented in the southeastern United States, yet this known invasive plant continues to be planted extensively in California's Central Valley, where it has recently naturalized in several locations. Climate modeling suggests that most of California's lowland riparian habitat is susceptible to i...

Control of biological invasions depends on the collective decisions of resource managers across invasion zones. Regions with high land-use diversity, which we refer to as "management mosaics", may be subject to severe invasions, for two main reasons. First, as land becomes increasingly subdivided, each manager assumes responsibility for a smaller p...

Private landowners are often de facto stewards of biodiversity and ecosystem services. In California's Sierra Nevada foothills, ranchers frequently present the only defense against biological invasions in private rangelands. Although ranchers' land management goals (e.g., the desire to control invasive species) can be consistent with ecosystem prot...