Treesearch

Gradient and scale are two key concepts in ecology and evolution that are closely related but inherently distinct. While scale commonly refers to the dimensional space of a specific ecological/evolutionary (eco–evo) issue, gradient measures the range of a given variable. Gradient and scale can jointly and interactively influence eco–evo patterns. Extensive previous research investigated how changing scales may affect the observation and interpretation of eco–evo patterns; however, relatively little attention has been paid to the role of changing gradients. Here, synthesizing recent...

The unintentional transport of insects beyond their native ranges has greatly increased with globalization over the past century, leading to higher propagule pressure in non-native ranges of many species. Knowledge about the prevalence of a species in international invasion pathways is important for predicting invasions and taking appropriate biosecurity measures. We investigated the spatiotemporal patterns and drivers of interceptions—detections of at least one individual with imported goods that potentially serve as a proxy for arrival rates—for a tree-killing bark beetle, the European...

The Asian longhorned tick (Haemaphysalis longicornis) is a vector of multiple arboviral and bacterial pathogens in its native East Asia and expanded distribution in Australasia. This species has both bisexual and parthenogenetic populations that can reach high population densities under favorable conditions. Established populations of parthenogenetic H. longicornis were detected in the eastern United States in 2017 and the possible range of this species at the continental level (North America) based on climatic conditions has been modeled. However, little is known about factors influencing...

Number preference, i.e., the human tendency to gravitate toward or away from specific numbers, is a potential source of measurement error in forest inventory. Identifying its presence is an important step to ensure unbiased results. This study evaluated U.S. national forest inventory data for number preference and identified factors that influence the proportion of tree cull volume, tree diameter, tree height, and seedling count observations ending with the digit zero or five (ED0,5) and seedling count observations that were multiples of four (M4). Two-sided hypothesis tests determined...

In material collected in 2017 in Antrim County, Michigan, USA, were three specimens of a flea beetle species misidentified at the time as belonging to the genus Crepidodera Chevrolat in Dejean, 1836 (Haack and Ruesink 2020). A recent reexamination of those specimens revealed that they actually belong to the genus Neocrepidodera Heikertinger, 1911.

1. Although many non-native species arrive in novel environments, only a fraction successfully establish. A crucial factor affecting the colonization process of invading species is propagule pressure. The positive association between propagule pressure and colonization probability is driven both by stochastic dynamics and the 'Allee effect'. Although the role of Allee effects in invading populations is theoretically compelling, they are difficult to quantify in the field because the earliest phases of biological invasions are typically not observed. 2. We conducted parallel studies using...

An extreme drought from 2012–2016 and concurrent bark beetle outbreaks in California, USA resulted in widespread tree mortality. We followed changes in tree mortality, stand structure, and surface and canopy fuels over four years after the peak of mortality in Sierra mixed conifer and pinyon pine (Pinus monophylla) forests to examine patterns of mortality, needle retention after death, and snag fall across tree species. We then investigated how the tree mortality event affected surface and canopy fuel loading and potential impacts on fire hazard and emissions.

Journals with open-discussion forums lend themselves well for peer review exercises to train early career scientists. Earth System Science Data (ESSD) is an open-access journal for the publication of interdisciplinary datasets and articles, and it is thus an example of an educational resource in the peer review process. We offer our experiences in peer review training with manuscripts submitted to ESSD, and we do so from the disparate perspectives of workshop instructor, student, and author. We then provide recommendations for the structure of a peer review workshop. We seek to promote the...

Increasing global temperatures and variability in the timing, quantity, and intensity of precipitation and wind have led to longer fire season lengths, greater fuel availability, and more intense and severe wildfires [1]. These broad-scale shifts have increased the emphasis on understanding wildland fuel dynamics through fine-scale laboratory experiments [2], refined fuel sampling strategies [3,4], the characterization of fuel hazards and treatment longevity [5,6], and operational fuel mapping [7,8]. Many of these efforts seek to enhance fuel estimation precision, along with the spatial...

Forest removal for livestock grazing is a striking example of human-caused state change leading to a stable, undesirable invasive grass system that is resistant to restoration efforts. Understanding which factors lead to resilience the alternative grass state can greatly benefit managers when planning forest restoration. We address how thresholds of grass cover and seed rain might influence forest recovery in a restoration project on Hawaiʻi Island, USA. Since the 1980s, over 400,000 Acacia koa (koa) trees were planted across degraded pasture and invasive grasses still dominate the...