Pencil Pushed: Exploring Process and Boundaries in Drawing (Exhibition Catalogue)

In Pencil Pushed, the word pencil functions simply as a metaphor or symbol for drawing and its activity. The selected artists are known for their drawing or drawing activity as their primary means of expression and have either pushed the material, process, or boundary of conventional drawing. Media included video, sculpture, animation, installation, and of course, works on paper. This exhibition is neither a survey nor the definitive grouping of mark-making artists. It is more a conversation about artists who have and continue to explore these regions in drawing. Featured artists in Pencil Pushed are: William Anastasi, William Pittman Andrews, Caroline Burton, Elisa D’Arrigo, Mary Reid Kelley, Sharon Louden, Jennifer Macdonald, Peter Mollenkof, Darcy Brennan Poor, Bill Richards, Beatrice Riese, Hilda Shen, Drew Shiflett, Stephen Talasnik, and Sam Verno

Factors Influencing Movement of the Manila Dunes and Its Impact on Establishing Non-Native Species

Unmanned aerial vehicles (UAVs) are being widely used to monitor microtopographic and vegetation changes in coastal habitats using remote sensing techniques. Sand dune habitats are vital ecosystems along the North coast of Humboldt County in California. This study was conducted at the Manila Dunes, west of the Humboldt Coastal Nature Center, in Manila, California. Various factors influence dune movements, including vegetative stabilization and the creation of social trails. The purpose of this paper is to understand the dune movements in relation to social vs. established trails, vegetation density, topography, and also, mapping invasive vs. native species in the Mal-le’l Dunes area of the Humboldt Bay National Wildlife Refuge. A DJI Mavic Pro multicopter small unmanned aerial vehicle (UAV) was used to fly a 22.5-acre plot of the Manila Dunes. The images from this flight were used to create an orthomosaic image using a photogrammetry process (Structure-from-Motion (SfM)). From our analysis, the installation of trails lessened the impact of dune movements. Social trails digitized within the study site were found to have more local movements than the established trails when compared to movements across the entire site. We compared two methods of classification, viz., the object-based feature extraction method and a pixel-based supervised maximum likelihood classification method, in order to identify the best way to classify dune vegetation. In conclusion, this study is useful for providing baseline dune movement information that can aid in informing how trail and infrastructure constructions can be impacted in land management or in areas with dynamic communities of flora and fauna

A transcontinental comparison of the diversity and composition of tropical forest understory herb assemblages

Although tropical forests are renowned for their high plant diversity, to date there has been no global quantitative evaluation of the local species richness of terrestrial forest herbs in tropical forests. In this paper, richness and composition of terrestrial herb assemblages is compared in tropical forests of America, Africa and South East Asia. We established 86 non-continuous transects of 445 m each. Herb species richness was analysed and compared to six environmental parameters using minimal adequate regression models and simultaneous autoregressive models. At the global scale, we found a close relationship between herb species richness and temperature parameters, with no differences between continents. The subdivision into three main taxonomic groups (ferns, monocots, dicots) showed that each group has distinct relations to environmental factors and differences in richness between continents. Most of the 72 families found have pantropical distributions but 12, 11, and 16 families were significantly over-represented in America, Africa, and Asia, respectively. Although total species richness was closely related to climatic factors, ferns, monocots and dicots were represented by distinct sets of families with varying species richness on each continent. Which species are found at a given site may thus reflect group-specific evolutionary and historical factors