Life Sciences Commons^™

Preliminary Report: A Survey Of Aggressive Behaviors In The American Coot (Fulica Americana) At Ballona Wetlands, California, Mariele Courtois, Kiara Cerda, Victor D. Carmona

Victor D. Carmona-Galindo

Insect Visitation Of Peduncular And Petiolar Extrafloral Nectar Glands On Castor Bean (Ricinus Communis L.) Plants In Southern California, Victor D. Carmona

Victor D. Carmona-Galindo

Castor bean (Ricinus communis L.) is a myrmecophytic plant species with specialized extrafloral nectar (EFN) glands that serve to attract predatory insects, which in return defend plant-tissues against herbivores. The EFN glands on castor bean plants are located along the leaf petioles as well as on the peduncles of its imperfect (unisexual) flowers. This field-project evaluates the richness, diversity, and species assemblage of insects visiting EFN glands located on (female and male) flower peduncles and leaf petioles on castor bean plants growing in a Southern California coastal landscape. We detected that EFN glands on female-flower peduncles were visited by an …

La Diversidad De Los Analisis De Diversidad [The Diversity Of Diversity Analyses], Victor D. Carmona

Victor D. Carmona-Galindo

There is a lack of consistency with respect to the use of the terms like species richness, diversity and biodiversity, which extends to the analysis of diversity indices and the merit of using diversity indices in the evaluation (comparison and contrast) of biological communities. The purpose of this article is to provide working definitions for these terms and cite examples from the primary literature that demonstrate the utility of estimating richness, evaluating proportional abundance patterns, as well as comparing indices of diversity and similarity to study patterns of biological organization at different ecological scales. Additionally, we provide a manual in …

Anthropogenic Impacts Of Irrigation On The Arthropod Community Structure Of A Coastal Sage Scrub Habitat In Los Angeles, Victor D. Carmona

Victor D. Carmona-Galindo

We evaluated the effects of an irrigation system on the community structure of arthropods in a coastal sage scrub chaparral habitat. We placed 5 traps in the irrigated site and 5 traps in control site, for a total of 10 sticky traps (using Tree Tanglefoot) in an area adjacent to Ballona Wetlands in Los Angeles, California. The traps were set at the irrigated and non-irrigated site on Telegraph Weed for one week. Results showed that morphospecies richness, relative abundance, and taxonomic order representation were higher at the control site than at the irrigated site. Our study documents how anthropogenic impacts …

Relationship Between Elaiosome And Efn Gland Size In Castor Bean (Ricinus Communis L.), An Exotic Mymercophyte In Southern California, Victor D. Carmona

Victor D. Carmona-Galindo

Castor bean (Ricinus communis L.) relies on seed dispersal by attracting ants with elaiosomes; lipid rich seed appendages, which serve as a source of food for ant larvae. Additionally, castor bean petioles and inflorescences have extra floral nectary (EFN) glands that secrete sugars that also attract ants, which in return, defend against herbivores. We propose that in order to attract ants, castor bean would have to balance allocation of energy toward plant defense and seed dispersal per the Principle of Allocation. Specifically, we hypothesized that in castor bean, an increase in elaiosome size would correspond to result in a decrease …

Differential Bait Preference And Rate Of Attraction By Argentine Ants (Linepithema Humile Mayr) At Freshwater And Saltwater Marsh Sites In Southern California, Victor D. Carmona

Victor D. Carmona-Galindo

Ants are a type of foraging insect species which harvests food resources based on availability. When ants locate food resources that are scarce within their habitat, they tend to be more strongly attracted to that food resource. This study used protein, carbohydrate and control based baits to examine if there was a deficiency in resources demonstrated by the ants at two different wetland habitats. We sampled Argentine ants (Linepithema humile Mayr) within the saltwater and freshwater marshes of Ballona Wetlands in Los Angeles, CA. We found significant differences in the rapid deployment of Argentine ants towards protein baits over carbohydrate …

The Impact Of Invasive Species Management Strategies On The Population Dynamics Of Castor Bean (Ricinus Communis L., Euphorbiaceae) At Two Southern California Costal Habitats, Victor D. Carmona

Victor D. Carmona-Galindo

The diverse uses of Ricinus communis L. (Castor bean) in herbalism, agriculture, and horticulture have facilitated the worldwide dispersal of this r-selected species. Management strategies to eradicate R. communis in southern California have largely relied on manual labor, which in turn is limited by budget. This study assesses how two different invasive species management strategies in southern California impact the survivorship and fecundity of naturalized R. communis populations. Our findings suggest that documenting patterns of survival and reproduction serve as a tool for the adaptive management of invasive species eradication efforts.

A Preliminary Study Of Heteromeles Arbutifolia Fruit Morphology At Ballona Wetlands And Temescal Canyon, Los Angeles, California, Victor D. Carmona

Victor D. Carmona-Galindo

Heteromeles arbutifolia, or the California holly, is an evergreen shrub native to chaparral habitats of Southern California that fruits from November to January. Fruit species morphology has been shown to be a good indicator of habitat quality among other plants. The variation in fruit morphologies was examined for the native plant at two diverse Southern California sites, a wetland and a canyon. California Holly fruits had a significantly greater volume in Ballona Wetlands than at Temescal Canyon (Z=4.367, P<0.001), as well as a significantly greater variance in Ballona Wetlands than at Temescal Canyon (F=2.357, P=0.02). The production of fruits with larger and more variable volumes in Ballona Wetlands may be a response to the presence of urban influences and environmental contaminants. As the reproductive structure, fruit morphology may be a good indicator of how habitat stress influences reproductive success.

Relationship Between Soil Sodium Concentration And Plant Height In Salicornia Virginica In The Ballona Wetlands In Los Angeles, California, Victor D. Carmona

Victor D. Carmona-Galindo

Previous studies have shown a positive relationship between biomass of the common wetland species of the halophyte, Salicornia virginica, and salinity (Callaway et al. 1998). Our research aims to implement a new technique that is less invasive than measuring total plant biomass which involves uprooting the plant. Instead, we have chosen to study the use of plant height as an indicator of sodium content in surrounding soils. Our hypothesis is that as plant height of S. virginica increases, there will be greater sodium content present in their corresponding soils. We found that plant heights had a significantly greater variation at …