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Significance of Bulb Polarity in Survival of Transplanted Mitigation Bulbs
Full text linkOur experimental design was formulated to determine whether or not bulb polarity (orientation) at the time of replanting of bulbs to salvage plants of Calochortus weedii A. W. Wood (Liliaceae) or Weed’s Mariposa Lily affected the success of the mitigation transplant effort. Polarity of bulbs at planting clearly did influence subsequent growth, most notably in the tip-down (D) treatment. Among these bulbs, 75% failed to emerge from dormancy and only four (20%) actually set mature fruit. This was in sharp contrast to the other three treatments where 100% of the bulbs successfully emerged in this season and between 80% (S) and 95% (UG and UN) set mature fruit. The data from this study do indicate that: 1) bulb planting orientation does influence survival and growth, and 2) proper bulb planting polarity (orientation) should be an important consideration in any transplantation of this or any sensitive bulb producing plant species for mitigation purposes
Comparison of the Marine Wood Borer Populations in Los Angeles Harbor in 1950-1951 with the Same Populations in 2013-2014
Full text linkA 14 month study was conducted of the marine wood borers present on monthly suspended wooden blocks at nine stations in Los Angeles Harbor in 2013-2014, and compared to the results of a marine borer study conducted in 1950-1951. Many environmental changes have occurred in the harbor over the past 60+ years. The harbor land mass of the outer harbor has been expanded towards the breakwater, channels were deepened, and the water quality improved as a result of pollution abatement. Existing pilings were removed, replaced or covered with two layers of polyethylene. The isopod Limnoria tripunctata and the pelecypod Lyrodus pedicellatus were the principal species and present at nearly all stations. Station C located in the Consolidated Slip area of the inner harbor was the site of 87 and 58 percent of the Limnoria and Lyrodus, respectively, counted during the study. Neither of these species was present at this station in 1950-1951. The dissolved oxygen concentration at this station improved from a mean of 0.1 ppm in 1950-1951 to a mean of 6.7 in 2013-2014 as a result of improved environmental conditions. Larval settlement at Station D numbered in the thousands in 1950-1951 but only 22 were counted during the 2013-2014 survey. This difference was attributed to the effect of piling covering or removal. It is recommended that existing creosoted pilings be covered or removed in the inner harbor area since this was the region of greatest occurrence of wood borers in 2013-2014