Stanford University
CESTA
A History of Conservation Land Acquisition in California
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A History of Conservation Land Acquisition in California
About this Visualization The overarching question of this inquiry deals with the spatial and temporal relationship between open spaces and species: Is Open Space protected after or before the detection of threatened/endangered species (T&E)?

This visualization depicts the timeline of detection of threatened and endangered Plants, Birds and Mammals concurrently with the timeline of conservation land acquisition in the last century in California to demonstrate the switching in conservation goals. In the late 19th century, land was acquired for the goals of conserving forests. With the implementation of flora and fauna surveys, acquisition of conservation land also attempts to meet conservation goals of T&E species.

What do we learn from this visualization? It can be observed that conservation land acquisition occurs firstly in the mountainous areas of the state, and only around 1940s that non-mountainous areas are conserved. It can also be observed that the detection of T&E (threatened and endangered) species follows the opposite pattern, with earlier detections in the coastal regions and followed by complementary detections in the mountain areas. T&E Plants detections occur much earlier since the beginning of our timeline; however, however their collection as specimens is very modest. In 1910s, there is a reverse of this pattern when vertebrates records become much higher than those of Plants, and Bird records were much higher than both Mammals and Plants. Mammal records only start in the 1910s, around the Bay Area, which are followed by a big effort to detect these species. After the earlier effort to archive Bird specimens, this taxonomic category becomes the less recorded through time, and their detection rates drop substantially in the 1960s. Plants only surpass Mammal detections in the 1980s.

Spatially, all T&E species detections occur around the Bay Area, while conservation land acquisition starts in the Sierras.

Plants soon are equally detected in southern areas of the state, around Los Angeles and San Diego; these two geographic areas are the center of Plant detection at the turn of the century. In 1910s T&E Plant detections start to occur in northern areas of the state and around the Sierras, and it is not until 1950s that areas of the Central Valley start to be surveyed for these species. The remainder of the century T&E Plant detections fill in these identified areas, with large areas of the state not being represented in this sample. Birds and Mammals also follow the same pattern of Plants in the turn of the century, with focal areas of detection in the Bay Area and Los Angeles and San Diego. However, and in contrast with Plants, in the 1920s there is higher portion of the state where T&E Bird and Mammal species are detected and recorded. This spatial spread in detection continues throughout the century.

Data Notes Open space data: To date we only have information on Open Space acquisition dates for 60% of the area of California that is considered Open Space.

Bias in species collection: species were collected by museums or organizations for their own purposes, not specifically to look at biodiversity, so a definite bias for where and when species were found. Further, some of the data lists the general locations species were found and not the specific place.
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