Testing reintroduction potential of Abronia macrocarpa (Nyctaginaceae)
Goodson, Jacqueline Jean
This study tests reintroduction as a mechanism to assist in recovery of Abronia macrocarpa, a federally and state endangered plant endemic to Texas. A series of laboratory tests were conducted to determine the most effective method for seed germination. Germination ranged from 0% to 68.6% among the control and twelve treatments. Seed germination was highest when achenes were scarified and subjected to warm followed by cold stratification. Three parcels of private property with suitable habitat were used as experimental reintroduction properties. A split-plot design was used to test the effects of timing of planting seed in the field (spring planted seed vs. fall planted seed). The mean percent germination of spring planted seed (4.2 to 16.67%) was higher than fall planted seed (0 to 0.83%) at all experimental properties. Germination of spring planted seed was significantly higher at experimental properties 1 and 2 when compared to experimental property 3 (p-value = 0.01303, F = 5.88, df= 2). The need for warm followed by cold stratification coupled with scarification may explain the higher percentage of germination of seed planted in the spring vs. the fall. Fall planted seed would not have been exposed to warm stratification. Experimental property 2 had a higher percentage of survivorship (87.5%) than experimental property 1 (19 .4% ). Plants at all stages of development (seedling, juvenile, anthesis) were observed at experimental property 2, but plants remained in the seedling stage at experimental properties 1 and 3. The levels of nitrate and potassium were higher at experimental property 2. This higher level of soil nutrients may be responsible for higher survivorship and plants reaching juvenile and anthesis stages in the first year of growth.
Nyctaginaceae, endangered plants, rare plants, habitat conservation, plant conservation, conservation biology
Goodson, J. J. (2007). Testing reintroduction potential of Abronia macrocarpa (Nyctaginaceae) (Unpublished thesis). Texas State University-San Marcos, San Marcos, Texas.