Treesearch

Although the use of nonhost plants intercropped among host crops has been a standard agricultural practice for reducing insect herbivory for millennia, the use of nonhost signals to deter forest pests is much more recent, having been developed over the past several decades. Early exploratory studies with synthetic nonhost volatile semiochemicals led to targeted electrophysiological and trapping experiments on a variety of bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) across three continents. This work disclosed a suite of antennally and behaviourally active nonhost...

Mangrove forests have adapted to sea level rise (SLR) increases by maintaining their forest floor elevation via belowground root growth and surface sediment deposits. Researchers use surface elevation tables (SETs) to monitor surface elevation change (SEC) in mangrove forests, after which this information is used to assess SLR resiliency or to dictate active forest management for vulnerable systems. This method requires significant investments in terms of time and human resources and is limited in the number of points it can measure per plot. We use a low‐cost, portable terrestrial laser...

1. In mixed stands, species complementarity (e.g. facilitation and competition reduction) may enhance forest tree productivity. Although positive mixture effects have been identified in forests world‐wide, the majority of studies have focused on two‐species interactions in managed systems with high functional diversity. We extended this line of research to examine mixture effects on tree productivity across landscape‐scale compositional and environmental gradients in the low functional diversity, fire‐suppressed, mixed‐conifer forests of the U.S. Interior West. 2. We investigated mixture...

Open forests of savanna and woodlands span the spectrum between closed canopy forests and treeless grasslands, and therefore contain structure, composition, and function distinctive from either endpoint. In this special issue, researchers provide examples from different open forest ecosystems to examine the underlying ecological principles and specific management challenges affecting successful restoration of these systems. Emergent themes include the role of open forest systems for biodiversity, fire as an underlying process, and the similarities and differences in ecosystem restoration...

Species distribution modelling (SDM) is a valuable tool for predicting the potential distribution of invasive species across space and time. Maximum entropy modelling (MaxEnt) is a popular choice for SDM, but questions have been raised about how these models are developed. Without biologically informed baseline assumptions, complex default SDM models could be selected, even though alternative settings may be more appropriate. Here we explored the effects of various SDM design strategies on distribution mapping of four forest invasive species (FIS) in Canada. We found that if we ignored the...

Context Ecological communities in urban ecosystems are assembled through ecological processes, such as species interactions, dispersal, and environmental filtering, but also through human factors that create and modify the landscape. These complex interactions make it difficult to untangle the relationships between social–ecological dynamics and urban biodiversity. Objectives As a result, there has been a call for research to address how human activities influence the processes by which ecological communities are structured in urban ecosystems. We address this research challenge using core...

Aim: Long-term monitoring of forest understorey species was used to describe changes in native and invasive exotic plant abundances over time within different disturbed or undisturbed forest types. This information was then used to determine the predictive invasion model (passenger/opportunist, driver or back-seat driver). Location: Cheat Ranger District of the Monongahela National Forest, West Virginia, USA. Methods: Understorey vegetation of mature and clear-cut forests was sampled every 5–6 years for 16 years. Stands were stratified across three land types following a moisture gradient....

The Adelges (Dreyfusia) piceae (Ratzeburg) species complex is a taxonomically unstable group of six species. Three of the species are cyclically parthenogenetic [Ad. nordmannianae (Eckstein), Ad. prelli (Grossmann), and Ad. merkeri (Eichhorn)] and three are obligately asexual [Ad. piceae, Ad. schneideri (Börner), and Ad. nebrodensis (Binazzi & Covassi)]. Some species are high-impact pests of fir (Abies) trees, so stable species names are needed to communicate effectively about management. Therefore, to refine species delimitation, guided by a reconstruction of their biogeographic history,...

Urban and agricultural communities are interdependent but often differ on approaches for improving water quality impaired by nutrient runoff waterbodies worldwide. Current water quality governance involves an overlapping array of policy tools implemented by governments, civil society organizations, and corporate supply chains. The choice of regulatory and voluntary tools is likely to influence many dimensions of the relationship between urban and agricultural actors. These relationships then influence future conditions for collective decision-making since many actors participate for...

Extremely high temperatures, which negatively affect the human health and plant performances, are becoming more frequent in cities. Urban green infrastructure, particularly trees, can mitigate this issue through cooling due to transpiration, and shading. Temperature regulation by trees depends on feedbacks among the climate, water supply, and plant physiology. However, in contrast to forest or general ecosystemmodels,most current urban treemodels still lack basic processes, such as the consideration of soil water limitation, or have not been evaluated sufficiently. In this study, we...