Treesearch

Many nations administer national forest inventory programs for unbiased estimation of forest attributes over broad spatial and temporal extents. However, management and conservation decisions often demand reliable estimates for finer spatiotemporal domains. In the western US, wildfire activity is expanding and postfire regeneration must contend with a warmer, drier climate. We evaluate the potential of K nearest neighbor (KNN) strategies for estimation of stocking across postfire measurements of Forest Inventory & Analysis plots in 11 western US states, and subsequently for model-assisted...

Disease may drive variation in host community structure by modifying the interplay of deterministic and stochastic processes that shape communities. For instance, deterministic processes like ecological selection can benefit species less impacted by disease. When communities have higher levels of disease and disease consistently selects for certain host species, this can reduce variation in host community composition. On the other hand, when host communities are less impacted by disease and selection is weaker, stochastic processes (e.g., drift, dispersal) may play a bigger role in host...

1. As communities assemble, species establishment can be driven by multiple factors. Two such factors, nutrients and consumers, are predicted to interact, but few studies have explored whether this interaction results from synergistically altering the same biotic and abiotic mediators or complementarily altering different mediators.2. To test this, I added seeds of multiple native species to old field communities in which I experimentally manipulated soil nutrients, leaf litter and consumers (insect herbivores and fungal pathogens). Using Bayesian hierarchical modelling, I evaluated the...

Growth and contraction of headwater stream networks determine habitat extent, and open a window to the hyporheic zone. A fundamental challenge is observation of this process: wetted channel extent is dynamic in space and time, with wetted channel length varying by orders of magnitude over the course of a single storm event in headwater catchments. To date, observational data sets are produced from boots-on-the-ground campaigns, drone imaging, or flow presence sensors, which are often laborious and limited in their spatial and temporal extents. Here, we evaluate satellite imagery as a means...

The sagebrush biome is a dryland region in the western United States experiencing rapid transformations to novel ecological states. Threat-based approaches for managing anthropogenic and ecosystem threats have recently become prominent, but successfully mitigating threats depends on the ecological resilience of ecosystems. We used a spatially explicit approach for prioritizing management actions that combined a threat-based model with models of resilience to disturbance and resistance to annual grass invasion. The threat-based model assessed geographic patterns in sagebrush ecological...

Lady beetles, ladybugs, or ladybird beetles (Coccinellidae) and their larvae feed on soft-bodied arthropods such as aphids, mealybugs, scales, whiteflies (Hemiptera), and mites (Arachnida) (Obrycki and Kring 1998), among others. Because of their diet, they are widely used as biocontrol agents in diverse ecosystems from agricultural to forests (Obrycki and Kring 1998; Tavares et al. 2014). In Puerto Rico, the lady beetle fauna consists of 53 described species, seven of which have been introduced as biological control agents (Segarra-Carmona et al. 2021). Introduced and native lady beetles...

Invasive clonal species may exhibit different growth strategies than their native clonal competitors. In this study, we examined the spatial distribution of tiller outgrowth and the bud bank by comparing the investment in phalanx versus guerilla growth of a native and invasive perennial grass in North America. We also examined the effect of altered precipitation frequency, clipping, and competition on their clonal growth strategies. Investment in phalanx and guerilla growth was assessed by examining live propagule and tiller production from the plant crown versus its rhizomes. Although...

Background: Contemporary and projected shifts in global fire regimes highlight the importance of understanding how fire affects ecosystem function and biodiversity across taxa and geographies. Pyrodiversity, or heterogeneity in fire history, is often an important driver of biodiversity, though it has been largely overlooked until relatively recently. In this paper, we synthesise previous research to develop a theoretical framework on pyrodiversity–biodiversity relationships and propose future research and conservation management directions.Theoretical Framework: Pyrodiversity may affect...

1. Ecological restoration is beneficial to ecological communities in this era of largescale landscape change and ecological disruption. However, restoration outcomes are notoriously variable, which makes fine-scale decision-making challenging. This is true for restoration efforts that follow large fires, which are increasingly common as the climate changes.2. Post-fire restoration efforts, like tree planting and seeding have shown mixed success, though the causes of the variation in restoration outcomes remain unclear. Abiotic factors such as elevation and fire severity, as well as biotic...

Aim: Managers are increasingly facing an uncertain future given changing climates and ecological trajectories. The interacting effects of climate, natural disturbance, and management actions complicate future projections, and there is a need for approaches that integrate these factors - especially for predicting future vegetation and species richness. Location: Central Sierra Nevada Mountains, USA.Methods: We used outputs from a spatially explicit landscape disturbance succession model that incorporated forest management actions, disturbance, and climate to estimate habitat and potential...