Sevilleta Larrea Seedling Monitoring Study
The germination rate of creosote (Larrea tridentata) on the Sevilleta appears to be very low. During the early years of the LTER project it was attempted to quantify such germination through the use of seedling plots which were monitored on a bi-annual basis (spring and fall). During the period from 1989 through 1992 there were no creosote seedling that germinated on the monitoring plots. In 1999 a rather sizeable population of small seedlings was observed in one quite localized area in the vicinity of Five Points. This rather large number of individuals in one very limited area raised several questions:1. When did this small community of individuals germinate- the supposition is that they had all germinated at the same time.2. What conditions existed in this particular location which allowed such prolific germination when there was no indication of virtually any other germination in this vicinty.3. The most immediate question was whether these seedlings would survive through the impending La Nina winter, spring and summer as many of the individuals did not appear to be very "healthy." To help answer these questions it was decided to begin a "small" monitoring project. All of the individuals in this small area thatappeared to be of the same age were marked with posts, located with GPS, measured (height) and photographed. This initial survey included 78 individuals. The population was resurveyed in August, 2000 and it was discovered that:1. Many individuals were missed in the initialsurvey. 2. Most of the individuals (72 of 78) had survived the intervening 9 months. 3. The average individual growth during this period was 1.4 cm. It is planned that this population will continue to be monitored(probably on an annual basis) to track survival and growth rate of these individuals.