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Salt marsh plants are a key source of primary productivity, ameliorate harsh abiotic conditions, and provide habitat structure to many organisms. As a consequence, rapid re-establishment of plant cover following restoration can speed the recovery of degraded ecosystems. Despite demonstrated positive relationships between plant biodiversity and ecosystem functions, many salt marsh restoration plans still incorporate single-species plantings under the belief that this approach will lead to faster increases in plant cover (a typical management goal). In this study, we evaluated post-restoration recovery of a non-vegetated high marsh berm in Brookhurst Marsh, Huntington Beach, CA, with two active planting strategies: monoculture plots of the competitive dominant Sarcocornia pacifica (pickleweed) versus polyculture plots of pickleweed and eight other common salt marsh plant species. Although monocultures did increase in total percent plant cover faster than polycultures, both treatments had reached 80-100% cover after one year, easily exceeding the permit-mandated goal of 20–40% cover in that time. The effects of increasing plant cover on abiotic parameters (e.g., % light reaching the ground, soil temperature, and soil salinity) were comparable between the two treatments and provided physical conditions sufficient to support similar macroinvertebrate communities. In contrast, plant species richness and canopy complexity were significantly higher in polyculture versus monoculture plots by the end of the experiment. Mean plant height was lower in polyculture plots, but maximum plant height (which can influence habitat use by perching birds) did not differ by treatment. Our data suggest that polyculture plots performed as well as, or better than, S. pacifica alone with respect to multiple indicators of ecosystem function. Active planting of high-diversity plots should therefore be seriously considered as a restoration tool to achieve common management goals in southern California salt marshes.
Polycera alabe and Polycera atra are closely related opisthobranch sea slugs found in coastal habitats along the eastern Pacific. Both species are extremely variable in external coloration and some of this variation appears to be correlated with geographic range. To determine the phylogenetic relationships and genetic structure of P. alabe and P. atra molecular phylogenies were generated using two genes: H3 (nuclear) and 16S (mitochondrial). Sequence data indicate that populations of P. atra are genetically homogeneous and lack geographic structure along the range of the species. In contrast, Polycera alabe consists of three previously unrecognized, distinct clades with overlapping ranges. The northernmost clade of P. alabe is sister to P. atra, thus the current definition of P. alabe constitutes a paraphyletic assemblage. The southernmost clade presents morphological differences in the radula compared to the other two clades. These data suggest that P. alabe is most likely a species complex.
Scotts Valley polygonum Polygonum hickmanii (Polygonaceae) is a narrow endemic plant restricted to a specialized microhabitat (exposed bedrock in California prairie) in Santa Cruz County, California. The species was named in 1995 and subsequently listed as endangered under the U.S. Endangered Species Act and California Endangered Species Act in 2003 and 2005, respectively. Two occurrences exist on three properties in a recently urbanized area at the northern edge of the city of Scotts Valley, with a geographic range of 0.03 km2. As of 2012 the species has declined to 128 plants on 61 m2, having decreased from 604 plants in 2003, 1,612 plants in 1998 and 2,388 plants in 1997. In 2013 the primary threats to P. hickmanii are habitat alteration due to adjacent land uses and developments, and invasive plant species and accumulation of thatch. Cessation of grazing and fire suppression have likely contributed to the increasing presence of invasive plant species and accumulation of thatch. Intensive and adaptive management with monitoring will be necessary for P. hickmanii to survive. Unless management is implemented as a matter of urgency, the species will likely disappear within just a few years.
The recovery strategy for an endangered species requires accurate knowledge of its distribution and geographic range. Although the best available information is used when developing a recovery plan, uncertainty often remains in regard to a species actual geographic extent. The arroyo toad (Anaxyrus californicus) occurs almost exclusively in coastal drainages, from Monterey County, California, south into northwestern Baja California, Mexico. Through field reconnaissance and the study of preserved museum specimens we determined that the four reported populations of the arroyo toad from the Sonoran Desert region of Riverside, San Diego, and Imperial counties, California are in error. Two additional sites in the Sonoran Desert are discussed regarding the possibility that the arroyo toad occurs there. We recommend the continued scrutiny of arroyo toad records to maintain a high level of accuracy of its distribution and geographic extent.
In order to access the endangered species status of any organism it is essential to know its past and present distribution. The Coast Lizard, Phrynosoma coronatum, was presumed to be threatened by habitat destruction due to human activities. I used historical literature and museum records to access past, and lizard survey teams to access current range and population numbers of P. coronatum in the five counties of Southern California between 1989–1991. The species occurs from sea level to 8,000′ (2348m) in a wide variety of habitats. Fieldwork and questionnaires increased by a third the number of locations (from 672 to 1148) where horned lizards are known to occur. There are (post 1985) records of the species throughout its range and from all habitats. The lizard occurred in about 75% of its original range, and of that, more than 50% is in public lands where the lizard is protected or could be protected by effective management and enforcement.
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