Search

Search Results

• 281. [Image] Pear orchard in bloom

  	View of Rogue Valley with blooming pear trees in front, Mt. McLoughlin (Mt. Pitt) in background
  	Citation × Citation Citation Abstract Copy Title: Pear orchard in bloom Author: Patterson (Photography studio of Frank and Josephine Patterson: Medford, Or., 1921-1929), Southern Oregon Historical Society Year: 1927 View of Rogue Valley with blooming pear trees in front, Mt. McLoughlin (Mt. Pitt) in background Title: Pear orchard in bloom Author: Patterson (Photography studio of Frank and Josephine Patterson: Medford, Or., 1921-1929), Southern Oregon Historical Society Year: 1927 View of Rogue Valley with blooming pear trees in front, Mt. McLoughlin (Mt. Pitt) in background Close

• 282. [Image] Central Point orchard view

  	View of young tree with larger trees beyond, and field crops, barns and a house in distance, with Roxy Ann Mountain in background on right
  	Citation × Citation Citation Abstract Copy Title: Central Point orchard view Author: Hull, Artist (Photography studios of Frank Hull: Medford, Or., ca. 1900-1911, Central Point, Or. 1912-1917), Southern Oregon Historical Society View of young tree with larger trees beyond, and field crops, barns and a house in distance, with Roxy Ann Mountain in background on right Title: Central Point orchard view Author: Hull, Artist (Photography studios of Frank Hull: Medford, Or., ca. 1900-1911, Central Point, Or. 1912-1917), Southern Oregon Historical Society View of young tree with larger trees beyond, and field crops, barns and a house in distance, with Roxy Ann Mountain in background on right Close

• 283. [Article] Agricultural impacts on amphibian survival, growth, and distributions

  The potential impact of chemical contaminants and conservation practices on amphibians in agricultural landscapes is a key research topic globally. Amphibians represent a common group in many freshwater ...

  Citation × Citation Citation Abstract Copy Title: Agricultural impacts on amphibian survival, growth, and distributions Author: Baker, Nick J. The potential impact of chemical contaminants and conservation practices on amphibians in agricultural landscapes is a key research topic globally. Amphibians represent a common group in many freshwater systems and are currently experiencing worldwide population declines. Global amphibian declines may be attributed to a number of causes, including habitat loss, introduced species, global climate change, disease, and chemical contaminants; most species declines are not a function of only one factor, but a result of interacting factors and synergistic impacts. I analyzed the impact of field conservation efforts employed in the Calapooia watershed, located in the central Willamette Valley in Oregon, on amphibian species diversity using Simpson's Diversity Index. In the Calapooia watershed the value of this index increased when conservation efforts, such as retaining crop residue and riparian buffers, were present. This suggests that species diversity increased with increased conservation effort at the field level. In addition, I found species-specific habitat associations in the Calapooia watershed. Long-toed salamanders (Ambystoma macrodactylum) were associated with stream channel cover. Rough-skinned newts (Taricha granulosa) and Red-legged frogs (Rana aurora) showed similar relationships to pH, bank width, depth, and riparian habitat where as Pacific treefrogs (Pseudacris regilla) showed strong relationships to increased structural heterogeneity, increased distance to nearest agricultural field, and increased human disturbance. These results indicate that conservation efforts can impact amphibian biodiversity, and that there are species-specific habitat associations in the Calapooia watershed. My third chapter looked at pesticides and fertilizers, which have been shown to negatively affect many species of amphibians. I used meta-analytic techniques to quantify the lethal and sub-lethal effects of pesticides and fertilizers on amphibians in an effort to review the published work to date. I found that, in general, pesticides and fertilizers negatively affect amphibians by reducing both survival and growth. Pesticide and fertilizer chemical classes showed differences in their impacts on amphibians: inorganic fertilizers, organophosphates, phosphonoglycines, and triazines negatively affected amphibian survival, while, organophosphates and triazines negatively affected amphibian growth. Title: Agricultural impacts on amphibian survival, growth, and distributions Author: Baker, Nick J. The potential impact of chemical contaminants and conservation practices on amphibians in agricultural landscapes is a key research topic globally. Amphibians represent a common group in many freshwater systems and are currently experiencing worldwide population declines. Global amphibian declines may be attributed to a number of causes, including habitat loss, introduced species, global climate change, disease, and chemical contaminants; most species declines are not a function of only one factor, but a result of interacting factors and synergistic impacts. I analyzed the impact of field conservation efforts employed in the Calapooia watershed, located in the central Willamette Valley in Oregon, on amphibian species diversity using Simpson's Diversity Index. In the Calapooia watershed the value of this index increased when conservation efforts, such as retaining crop residue and riparian buffers, were present. This suggests that species diversity increased with increased conservation effort at the field level. In addition, I found species-specific habitat associations in the Calapooia watershed. Long-toed salamanders (Ambystoma macrodactylum) were associated with stream channel cover. Rough-skinned newts (Taricha granulosa) and Red-legged frogs (Rana aurora) showed similar relationships to pH, bank width, depth, and riparian habitat where as Pacific treefrogs (Pseudacris regilla) showed strong relationships to increased structural heterogeneity, increased distance to nearest agricultural field, and increased human disturbance. These results indicate that conservation efforts can impact amphibian biodiversity, and that there are species-specific habitat associations in the Calapooia watershed. My third chapter looked at pesticides and fertilizers, which have been shown to negatively affect many species of amphibians. I used meta-analytic techniques to quantify the lethal and sub-lethal effects of pesticides and fertilizers on amphibians in an effort to review the published work to date. I found that, in general, pesticides and fertilizers negatively affect amphibians by reducing both survival and growth. Pesticide and fertilizer chemical classes showed differences in their impacts on amphibians: inorganic fertilizers, organophosphates, phosphonoglycines, and triazines negatively affected amphibian survival, while, organophosphates and triazines negatively affected amphibian growth. Close

• 284. [Image] Former veterans cultivating sugar beets on their leased land near Tulelake, California

  	KP-1208-R2 - Klamath Project. Region II. Two veterans who have leased a small parcel of land in the Klamath Project near Tulelake, California, are cultivating a patch of sugar beets that have grown in ...
  	Citation × Citation Citation Abstract Copy Title: Former veterans cultivating sugar beets on their leased land near Tulelake, California Author: United States. Bureau of Reclamation, Fluharty, J.E. Year: 1946, 2006, 2005 KP-1208-R2 - Klamath Project. Region II. Two veterans who have leased a small parcel of land in the Klamath Project near Tulelake, California, are cultivating a patch of sugar beets that have grown in many places on the Klamath Project and are shipped to the Spreckles Refinery in Woodland, California; June 26, 1946; Photo by J. E. Fluharty Title: Former veterans cultivating sugar beets on their leased land near Tulelake, California Author: United States. Bureau of Reclamation, Fluharty, J.E. Year: 1946, 2006, 2005 KP-1208-R2 - Klamath Project. Region II. Two veterans who have leased a small parcel of land in the Klamath Project near Tulelake, California, are cultivating a patch of sugar beets that have grown in many places on the Klamath Project and are shipped to the Spreckles Refinery in Woodland, California; June 26, 1946; Photo by J. E. Fluharty Close