12 research outputs found
Regeneration of native trees in the presence of invasive saltcedar in the Colorado River Delta, Mexico
Many riparian zones in the Sonoran Desert have been altered by elimination of the normal flood regime; such changes to the flow regime have contributed to the spread of saltcedar (Tamarix ramosissma Ledeb.), an exotic, salt-tolerant shrub. It has been proposed that reestablishment of a natural flow regime on these rivers might permit passive restoration of native trees, without the need for aggressive saltcedar clearing programs. We tested this proposition in the Colorado River delta in Mexico, which has received a series of large-volume water releases from U.S. dams over the past 20 years. We mapped the vegetation of the delta riparian corridor through ground and aerial surveys (1999-2002) and satellite imagery (1992-2002) and related vegetation changes to river flood flows and fire events. Although saltcedar is still the dominant plant in the delta, native cottonwood (Populus fremontii S. Wats.) and willow (Salix gooddingii C. Ball) trees have regenerated multiple times because of frequent flood releases from U.S. dams since 1981. Tree populations are young and dynamic (ages 5-10 years). The primary cause of tree mortality between floods is fire. Biomass in the floodplain, as measured by the normalized difference vegetation index on satellite images, responds positively even to low-volume (but long-duration) flood events. Our results support the hypothesis that restoration of a pulse flood regime will regenerate native riparian vegetation despite the presence of a dominant invasive species, but fire management will be necessary to allow mature tree stands to develop. ©2005 Society for Conservation Biology
Monthly Water Balance of an Iconic Coastal Desert Wetland Under Reduced Flows and Increased Salinities; Implications for Management
Regeneration of Native Trees in the Presence of Invasive Saltcedar in the Colorado River Delta, Mexico
Genetic variation in the Desert Springsnail (Tryonia porrecta): implications for reproductive mode and dispersal
Tamarix as Habitat for Birds: Implications for Riparian Restoration in the Southwestern United States
(Des)iguales y (des)conectados : políticas, actores y dilemas info-comunicacionales en América Latina
En este libro nos proponemos trabajar sobre uno de los problemas contemporáneos del campo, que quedó expuesto con crudeza a partir de la catástrofe planetaria que ha significado la pandemia "COVID 19: la desigualdad info-comunicacional, que tiene a la conectividad y a su reverso, la desconexión, como algunos de sus puntos medulares.
Ecosystem-Based Fisheries Management of a Biological Corridor Along the Northern Sonora Coastline (NE Gulf of California)
Search for transient gravitational waves in coincidence with short-duration radio transients during 2007-2013
We present an archival search for transient gravitational-wave bursts in
coincidence with 27 single pulse triggers from Green Bank Telescope pulsar
surveys, using the LIGO, Virgo and GEO interferometer network. We also discuss
a check for gravitational-wave signals in coincidence with Parkes Fast Radio
Bursts using similar methods. Data analyzed in these searches were collected
between 2007 and 2013. Possible sources of emission of both short-duration
radio signals and transient gravitational-wave emission include starquakes on
neutron stars, binary coalescence of neutron stars, and cosmic string cusps.
While no evidence for gravitational-wave emission in coincidence with these
radio transients was found, the current analysis serves as a prototype for
similar future searches using more sensitive second-generation interferometers