Welcome to the kellylab page!

Our motto is "mapping for a changing California", and we use a range of mapping techniques - remote sensing, object-based image analysis, geospatial modeling, lidar analysis, participatory webGIS and field-based monitoring - to answer applied questions about how and why California landscapes are changing, and what that means for the people who live on, derive sustenance from, and manage them. Here you will find information on people in our lab, our projects, and some connections to other groups and sites of interest. For more on geospatial technology on campus, check out the geospatial innovation facility (GIF) and the GIS@Berkeley website. Enjoy, check out the blog, and stay in touch.

Tuesday
Jan202015

VTM data helps us understand changes to California forests

Check out our PNAS paper: Twentieth-century shifts in forest structure in California: Denser forests, smaller trees, and increased dominance of oaks.

In the paper we document changes in forest structure between historical (1930s) and contemporary (2000s) surveys of California vegetation. The shorthand is:

  1. Statewide, tree density in forested regions increased by 30% between the two time periods, and forest biomass declined by 19%.
  2. Larger trees (>60 cm diameter at breast height) declined, whereas smaller trees (<30 cm) have increased.
  3. Large tree declines were more severe in areas experiencing greater increases in climatic water deficit since the 1930s.
  4. Forest composition in California in the last century has also shifted toward increased dominance by oaks relative to pines, a pattern consistent with warming and increased water stress, and also with paleohistoric shifts in vegetation in California over the last 150,000 years.

About the data: We've got the plot data, plot maps, maps, photos and photo locations available for download. Check it out!  Please check it out and think about how these data can be of use in your research. The journey from paper collection to digital data has been a long one, with several cases of almost accidental and purposeful destruction. As such it is a cautionary tale about the importance of rescued and shared historical data in ecological and geographical analysis. We owe much to all the people who have contributed to the preservation and digitization of this important collection. Thanks to so many people who have been working on this project since the early 2000s: Barbara Allen-Diaz, James Thorne, Ken-ichi Ueda, the late great Norma Kobzina, Ann Huber, Shruti Myukhtar, Falk Schuetzenmeister, Kelly Easterday and Shufei Lei, and all of my lab group who digitized the plot data for no reward, and many many others.

I've been collecting tidbits about the collection here, including examples of photo reshoots.