Proceedings of the 21st Annual Urban Ecology & Conservation Symposium (2023)

These proceedings document the agenda and abstracts for presentations and posters from the 21st annual conference organized by the Urban Ecosystem Research Consortium of Portland/Vancouver (UERC). The UERC is a consortium of people from various universities and colleges, state and federal agencies, local governments, non-profit organizations and independent professionals interested in supporting urban ecosystem research and creating an information-sharing network of people that collect and use ecological data in the Portland/Vancouver area. The annual conference has an open call for abstracts. The UERC organizing committee selects the final oral and poster presentations, along with 2 invited keynote presentations

Riparian bird communities in Portland, Oregon : habitat, urbanization, and spatial scale patterns

Urban ecosystems are characterized by human disturbance and changes in the amount, types, and spatial arrangement of wildlife habitat. The relative importance of habitat and human associated variables to urban birds is unknown. In 1999, I surveyed spring bird and plant communities along 54 perennial streams in the Portland, Oregon metropolitan region. My objectives were to determine (1) what habitat and human-associated variables were related to avian community measures, (2) how far from riparian areas did relationships between avifauna and canopy cover and development extend, and (3) habitat characteristics associated with individual bird species. I used Principal Components Analysis to cluster and reduce the number of explanatory variables, and regressed bird community variables against the resulting principal components. Total and nonnative bird abundance were negatively related to the first principal component, PC 1 (high-scoring PC 1 sites had wide, structurally complex native forests) (r2 = 0.38, P < 0.0001 and r2 = 0.63, P < 0.0001, respectively). Several weak (r2 = 0.17-0.31, P < 0.003) curvilinear relationships emerged between overall and native species richness and diversity versus PC 1. Neotropical migratory bird (NMB) species richness and diversity were negatively related to human development variables, and positively related to native shrubs (adjusted r2 = 0.21 and 0.18, respectively; P < 0.003). I regressed bird community variables against canopy cover and street density for each of ten 50-m buffers around sites, then plotted the model fit (r) against buffer width. Native and nonnative abundance measures were negatively related to canopy cover. Total abundance was best predicted by canopy cover 300-350 m from the stream whereas normative abundance was predicted nearly equally by canopy cover in each buffer. The relationships between total species richness, native species richness, total diversity and native diversity were curvilinearly related to canopy cover, with canopy in the first 50 m appearing most important. Neotropical migratory bird species richness, diversity and abundance were negatively related to street density within 150 m of the stream. Brown-headed Cowbird (Molothrus ater) abundance was increasingly, negatively related to canopy cover as spatial scale increased. I used logistic regression to identify habitat and/or human-associated variables that predicted the occurrence of 32 species. The occurrence of four species (American Crow [Corvus brachyrhynchos], House Finch [Carpodacus mexicanus], Red-breasted Nuthatch [Sitta canadensis], and Vaux's Swift [Chaetura vauxi]) was positively, and five species (Black-headed Grosbeak [Pheucticus melanocephalus], Common Yellowthroat [Geothlypis trichas], Rufous Hummingbird [Selasphorus rufus], Steller's Jay [Cyanocitta setlleri], and Swainson's Thrush [Catharus ustulatus]) negatively related to human-associated variables. My results suggest that increasing urban canopy cover is the most valuable land management action for many breeding bird species. Preserving large undeveloped habitats and controlling urban sprawl may help prevent regional declines of NMB species

Metro Habitat Connectivity Toolkit: Bringing Connectivity to an Actionable Scale

Habitat fragmentation is a serious threat to maintaining biodiversity particularly in urbanizing areas. Methods exist to model habitat connectivity, however many of these are applied at large scales and rely on data that may be a decade or older, resulting in inaccuracies when compared to on the ground conditions, particularly in dynamic urban systems that experience rapid change. These issues make taking action to preserve or enhance these connectivity zones difficult, if not impossible. The Metro Regional Habitat Connectivity Toolkit approaches this problem by combining GIS analysis with on the ground assessments at realistic scales for land acquisition, restoration projects and/or barrier mitigation. We employed a surrogate species approach to address connectivity needs in a way that incorporates empirical data. Local information and research was combined with other habitat attributes to focus development of field assessments for habitat quality and barrier permeability. The field assessments allow technicians to verify GIS data, identify barriers and record habitat attributes in a way that is comparable across multiple habitat connectivity zones and for multiple species. Once assessments are concluded the resulting information is used to generate two species specific scores for habitat quality and barrier permeability. These scores identify where on the landscape restoration and/or land acquisitions would provide the most connectivity benefit vs areas where mitigation for barriers such as wildlife passages structures across roads are the priority. This toolkit is in the final stages of development and is currently being testing in pilot areas in the Portland Metro region

Metro Habitat Connectivity Toolkit: Bringing Connectivity to an Actionable Scale

Habitat fragmentation is a serious threat to maintaining biodiversity particularly in urbanizing areas. Methods exist to model habitat connectivity, however many of these are applied at large scales and rely on data that may be a decade or older, resulting in inaccuracies when compared to on the ground conditions, particularly in dynamic urban systems that experience rapid change. These issues make taking action to preserve or enhance these connectivity zones difficult, if not impossible. The Metro Regional Habitat Connectivity Toolkit approaches this problem by combining GIS analysis with on the ground assessments at realistic scales for land acquisition, restoration projects and/or barrier mitigation. We employed a surrogate species approach to address connectivity needs in a way that incorporates empirical data. Local information and research was combined with other habitat attributes to focus development of field assessments for habitat quality and barrier permeability. The field assessments allow technicians to verify GIS data, identify barriers and record habitat attributes in a way that is comparable across multiple habitat connectivity zones and for multiple species. Once assessments are concluded the resulting information is used to generate two species specific scores for habitat quality and barrier permeability. These scores identify where on the landscape restoration and/or land acquisitions would provide the most connectivity benefit vs areas where mitigation for barriers such as wildlife passages structures across roads are the priority. This toolkit is in the final stages of development and is currently being testing in pilot areas in the Portland Metro region

Mapping Oak within the RCS Bundary

The Oak Prairie Work Group’s Oregon white oak map is nearly complete. All areas within the \u3e2,800-square mile Intertwine Alliance Regional Conservation Strategy (RCS) boundary will be finished by June 30, 2018. We will describe the mapping process and show the results. Purpose: This work fulfills a high priority RCS goal. The results will be used to update RCS habitat maps; prioritize important oak habitat and connectivity areas; and support effective, collaborative habitat protection, stewardship and education. Methods: In 2012 we collected field samples of oak habitat to help develop a potential remote sensing model approach. From 2013-2015 Metro used thousands of oak tree locations collected by \u3e180 community scientists, plus points collected via aerial photographs, to refine model iterations. Despite our best efforts, models substantially overestimated the amount of oak, partially due to the hundreds of tree species present in urban areas. We needed more accurate information. We became skilled at identifying oak trees from aerials by checking every oak point collected by community scientists. In 2015 we abandoned remote sensing efforts and began to systematically hand-map oak trees using aerial photos. Results: Approximately 10% of all mapped oaks are in protected areas. The results show clear spatial patterns in oak distribution, including large patches and potential wildlife connectivity pathways in both urban and rural areas. Many fall outside of RCS “high value habitat” areas modeled in 2012, which lacked oak data at the time. We will freely share the data and are currently developing data viewing tools

Using wildlife fright information to inform trail planning

In 2017 I completed a recreation ecology literature review that included information on various wildlife species\u27 Flight Initiation Distance (FID), or the distance between a person and an animal at which point the animal flees. The review covered many topics at a higher level. To inform trail planning and publish a peer-reviewed journal article, I took a closer look at the FID literature and located numerous additional references. I will briefly summarize the updated findings and present several hypothetical scenarios in which we applied FID information to reduce recreational effects on wildlife while still providing quality visitor experiences in nature

Mapping Regional Wildlife Habitat Connectivity

We developed a wildlife habitat connectivity map for the Oregon portion of the Regional Conservation Strategy boundary. To make this map we solicited species experts for the Northern red-legged frog (Rana aurora), American beaver (Castor canadensis), and Douglas squirrel (Tamiasciurus douglasii) in order to determine the salient habitat requirements for each species. We then created GIS models of each specie’s probable distribution over the study area. The models are composed of landcover, maximum size of a canopy gap the animal will cross, maximum distance from water, aversion to development and much other data. The intention was to create a model that shows the spatial distribution of habitat as well as areas that are not habitat but through which the animal will travel and areas that are a barrier to the animal’s movement. We used these models to create raster layers that depicted the permeability of the landscape to animal movement and then modeled movement pathways in Circuitscape, a program that uses circuit theory to determine how well a set of points are connected based on a resistance surface. We used all of the Metro managed properties as the anchors for the connectivity modeling. We ran the model for all three surrogate species and then combined the models into a map of regional wildlife habitat connectivity. This effort will be repeated in the next several years for an additional 30-40 species as part of a larger effort by OCAMP to map statewide wildlife habitat connectivity

Metro’s Bond Refinement: Identifying acquisition priorities in the Urban Target Area

In November 2019, the region’s voters approved a $475 million bond measure to protect clean water, restore fish and wildlife habitat and provide opportunities for people to connect with nature close to home. It was the third such measure over the past 25 years. Each bond measure presented the public with a set of carefully selected “target areas” (TAs) within which properties may be purchased from willing sellers using bond funds. Once a bond passes, TAs undergo a “refinement process” to identify a high priority subset of lands based on a suite of criteria. All three bonds share goals for healthy streams and habitat and included substantial governmental and community outreach, and but the 2019 bond differs in three important ways: (a) it prioritizes racial equity and Indigenous needs, (b) for the first time it includes an Urban TA, and (c) it specifically emphasizes opportunities to increase climate change resilience. To support equity and climate goals for the 2019 bond Metro’s contractor, Knot, produced models based on existing datasets such as tree cover, water resources, priority habitats and species, census data and habitat connectivity; and new datasets, the latter including: equity focal areas, urban heat island areas based on methods of Dr. Vivek Shandas’ lab (Voelkel et. al 2018), and the potential effects of upper watershed management on urban flooding. The Urban TA provides an outstanding suite of high-value habitat areas that intersect with opportunities to increase racial equity and strengthen communities’ climate change resilience. Here we will describe refinement methods and results pertaining to the Urban TA

UERC 2022 Symposium Day 2 Recording

Urban Ecosystem Research Consortium (UERC) Portland, OR - Vancouver, WA Metropolitan Region, 2022 Symposium Day 2 recording. Containing keynote and presentations given on March 8th 2022