Spatial Analysis of Mixed-conifer Seedling Dispersal in Contrasting Regeneration Environments

95th Ecological Society of America (ESA) Annual Meeting, Pittsburgh, PA, 01-06 August 2010

Seth W. Bigelow and Michael J. Papaik

“Background/Question/Methods: Mixed-conifer forests of the Sierra Nevada underwent a marked shift to dominance by shade-tolerant trees during the 20th century, but the concomitant emergence of a disturbance regime of large high-intensity fires may now provide opportunities for establishment of shade-intolerant pine species. We assessed conifer seedling establishment in stem-mapped tree stands representing three regeneration environments: isolated remnant patches nine yr after high-intensity fire, contiguous stands nine yr after low-intensity wildfire, and silvicultural openings ~1 ha in size. We asked how seedling density varied as function of distance from parent tree, and how seedling establishment varied among substrate type (e.g., conifer litter compared to bare soil), and how substrate availability varied among regeneration environments. Seedling density was estimated as a function of distance from parent tree and substrate favorability, assuming a log-normal dispersal curve.

“Results/Conclusions: Only ponderosa pine and white fir were sampled in sufficiently high numbers to allow estimation of dispersal parameters. Modal ponderosa pine dispersal distance was 45 m, almost twice the distance of white fir. Ponderosa pine seedling distribution was narrowly clustered around the modal dispersal distance, possibly because of dispersal limitation from large seed size. White fir, which has smaller seeds, maintained high dispersion densities at relatively long distances from individual trees. Ponderosa pine seedlings established preferentially in areas of high herbaceous cover, and white fir preferred bare soil. Conifer litter was the most common substrate by a wide margin in all regeneration environments, and even though it was not the most favorable substrate for either species it accounted for a high proportion of seedling occurrences. Group selection openings had a larger proportion of bare soil than the other environments (25% of soil surface vs. 12-15% in burned areas), which was associated with dense white fir regeneration. We conclude that adequate regeneration of the shade-intolerant ponderosa pine was occurring in group-selection openings, but insufficient natural regeneration of pine was occurring in the post-fire environments to effect substantial change in relative abundance of shade-intolerant species.”

BP’s Standard of Care to be Hot Topic at GIS-Pro 2010 Conference

Did BP Fail Standard of Care Tests? Dr. Barry Wellar, Professor Emeritus, Geography and Environmental Studies, University of Ottawa, Canada, questions whether a possible failure to properly apply standard of care tests contributed to BP’s massive oil spill in the Gulf of Mexico. Dr. Wellar, a distinguished research scientist and President of the Information Research Board, will discuss the BP case at two featured conference sessions during URISA’s 2010 GIS-Pro Conference in Orlando, Florida.

“Every individual and corporation has duty of care and standard of care responsibilities, and those responsibilities can be moral, ethical, and legal in nature.” says Wellar. “In the BP-Gulf of Mexico incident the actionable responsibilities of consequence are those involving legal liability, and the liability can be civil as well as criminal.”

“To get a handle on the degree of liability, we will outline how proper regard for standard of care principles could have precluded or significantly mitigated the BP oil incident. And, we will explore how geographic information systems (GIS) can assist in establishing the damage zone, and the geographic extent of BP’s legal liability.”

However, says Dr. Wellar, this is not just a discussion for experts.

“I believe that these sessions on standard of care will assist the media, and ordinary citizens, to more critically assess what BP, the fossil fuel industry, and governments are actually doing to fix this oil spill mess, and to prevent future messes.”

Dr. Wellar is also concerned that too many people may erroneously regard the Gulf of Mexico disaster as someone else’s problem.

“There are current and proposed drilling sites around the world that are in or near bodies of water, and we are long overdue for comprehensive and critical analyses of standard of care practices by the oil and gas industry. The BP-Gulf disaster is a brutal wake-up call that should have been anticipated and heeded decades ago.”

URISA President Kathrine Cargo, from the Orleans Parish Communication District, New Orleans, LA, welcomes this discussion about the BP-Gulf of Mexico situation.

“Dr. Wellar’s presentations provide a totally different look at the oil spill situation by someone who for decades has done outstanding work on public policy matters, and he has expert witness experience involving standard of care issues. We think that this discussion at the URISA’s 2010 GIS-Pro Conference will be very valuable locally, nationally, and internationally.”

Information about Dr. Barry Wellar is posted at

For details about the GIS-Pro 2010 Conference contact Wendy Nelson or visit the URISA website at

GIS-Pro 2010: URISA’s 48th Annual Conference for GIS Professionals
September 28 – October 1, 2010
Hilton Orlando Bonnet Creek
Orlando, Florida

[Source: URISA press release]

The Circular Dataimage, A Graph for High-resolution Circular-spatial Data

International Journal of Digital Earth, Volume 3, Issue 1 March 2010 , pages 47 – 71

William J. Morphet; Jürgen Symanzik

“Vectors and periodic phenomena, e.g. traffic versus time, have direction on a circular scale of 360°. An overview of existing methods for the display of circular-spatial and vectorial-spatial data, such as arrow plots, is given. We introduce the circular dataimage, a new type of graphic for the display of circular-spatial data. It is defined by encoding direction in a spatial display by using colors from a color wheel constructed by connecting three or more two-color gradients with color continuity at the connections. Therefore, image discontinuity from using a single-color gradient, e.g. blue-red, does not occur. High-resolution global views of ocean wind direction are used as a running example throughout the paper. Advantages and disadvantages of circular dataimages compared to arrow plots were obtained from a usability study. Circular dataimages provide for simultaneous recognition of fine structure on a small-scale and large-scale structure on a global scale.”

Geographic and Temporal Analysis of Folate-Sensitive Fetal Malformations

Reproductive Science: Journal of the Society for Gynecologic Investigation, July 2003 10: 298-301

Trent E. J. Gordon, MS, Elizabeth A. Leeth, MS, Cynthia J. Nowinski, MD, Scott N. MacGregor, DO, Michelle Kambich, MS, and Richard K. Silver, MD

“Objective: To identify potential geographic and temporal clustering of folate-sensitive fetal malformations as a prelude to a targeted preconception curriculum in folic acid supplementation.

“Methods: Our comprehensive prenatal anomaly database was queried to select fetal malformations presumed to be sensitive to preconception folate insufficiency. Evidence of geographic clustering was evaluated by distribution of individual cases using zip codes of matermal residence. Potential temporal clustering of anomalies was sought by tabulating the frequency of each anomaly category during 5 consecutive 2-year intervals between 1992 and 2001.

“Results: Over a 10-year period, approximatley 2000 fetal anomalies were identified, of which 400 (20%) were considered potentially folate sensitive. We found geographic clustering of ventral wall defects as well as obstructive uropathy by zip code analysis. Significant increases in the frequencies of cardiac defects (P < .001) and obstructive uropathy (P < .001) were noted during the epoch of this study. A moderate increase in anomaly frequency was also seen in the diagnostic subcategory of gastroschisis, in which 15 of 27 total gastroschisis cases occurred in 2000-2001.

“Conclusion: Geographic clustering and temporal trends in anomally rates were noted in certain folate-sensitive malformation categories. Identification of specific, high-incidence regions may provide an opportunity for targeted interentions designed to supplement the national folic acid campaign.”

Grain Levels in English Path Curvature Descriptions and Accompanying Iconic Gestures

Journal of Spatial Information Science, Number 1 (2010), pp. 95-113

Emile van der Zee, Urpo Nikanne, and Uta Sassenberg

“This paper confirms that the English verb system (similar to the Finnish, Dutch, and Bulgarian verb systems) represents path curvature at three different grain levels: neutral path curvature, global path curvature, and local path curvature. We show that the three-grain-level hypothesis makes it possible to formulate constraints on English sentence structure and makes it possible to define constructions in English that refer to path curvature. We furthermore demonstrate in an experiment that the proposed English lexicalization pattern regarding path curvature in tandem with the spatial information shown to English speakers correctly predicts their packaging of grain levels in iconic gestures. We conclude that the data studied confirm Nikanne and Van der Zee’s three-grain-level hypothesis in relation to English and Kita and Ozyurek’s interface hypothesis in relation to gesture production.”

Urban Road Network Accessibility Evaluation Method base on GIS Spatial Analysis Techniques

Proceedings, URISA XXXVIII

Hu Weiping and Wu Chi

“The urban road network plays a key role in the urban spatial structure. It is the main city social-economy activities and transportation carrier. Today, more and more researchers pay attention on road network. One of the most important problems is how to evaluate the accessibility of road network. This paper tries to discuss it. Firstly, road accessibility concept and some appraisal methods are discussed. Then, the spatial analysis method on road network assessment has established based on the GIS spatial analysis technology, some urban road network accessibility evaluation models are built up. The models use ESRI Corporation’s ArcGIS Engine components and Microsoft Corporation. Net Framework, and focus on the road network connectivity, the shortest travel time and the weighted average travel time. The paper presented three main road network accessibility evaluating indicators, introduced theory basis of the model construction in detail, and the model construction process. Taking Foshan city as an example, the models were tested using the urban road network data. Finally, further urban road network accessibility evaluation models are discussed.”