Carrizo Plain National Monument Vegetation Project (October 2010)

This past summer of 2010, CNPS Vegetation Program staff and partners successfully completed a baseline of vegetation sampling across more than 240,000 acres of the Carrizo Plain National Monument. This project is in collaboration with Bureau of Land Management (BLM) and Department of Fish and Game (DFG). A main goal of the project is to provide Monument managers with baseline vegetation data and a detailed map of vegetation types for use in evaluating climate change effects over time.

We initiated the project in 2008, with initial funding from DFG to conduct field vegetation surveys. In 2010, BLM provided additional funding and expanded the project to complete baseline vegetation surveys and to produce a fine-scale vegetation map across the Monument. This project also builds upon our Grasslands Initiative by enhancing the data available on herbaceous vegetation of the San Joaquin Valley.

This year’s sampling began in March during peak blooming season. The Monument is topographically diverse, encompassing the Caliente Range in the southwest, alkali sinks in the Plain’s valley bottom, and the dry Temblor Range including the Elkhorn Hills in the northeast. For this reason, surveys were carefully orchestrated to occur first in the lowest/driest areas, then continued upslope and to the less arid west as the season progressed. During a nine-week period, four CNPS staff conducted over 350 surveys, with additional surveys conducted by multiple DFG staff.

Surveys also included the establishment of several long-term monitoring plots in a broad range of vegetation communities including herbaceous communities (Amsinckia tessellata, Salvia carduacea), semi-desert shrublands (Atriplex spinifera, Ephedra californica), and woodlands (Juniperus californica, Quercus john-tuckeri).

In general there is a north-south rainfall gradient in the Monument, with the south receiving more rainfall. To capture this variation, long-term monitoring plots for some vegetation communities were replicated in both the northern and southern portions of the Monument.

In addition to the blinding wildflower displays and the noisy bustle of pollinators, we also had the opportunity to experience much of the Monument’s wildlife. In the early morning hours, badger and coyote were spotted along the less traveled roads. In the later afternoons, antelope could often be seen in the valley bottom where they gather for the spring calving season.

Coast horned lizard (Phrynosoma blainvillii) was a regular sight, and we had a rare glimpse of the federally endangered blunt-nosed leopard lizard (Gambelia sila). As the season progressed, it became increasingly common to stumble over large haystacks created by giant kangaroo rats in preparation for winter.

With the field sampling wrapped up, we are now transitioning into the next phases of the project. CNPS staff is analyzing the survey data to establish a hierarchical classification of vegetation in the Monument, which will be used as the basis for the mapping.

We have already analyzed a small grassland dataset from a pilot mapping area, and we will be naming new vegetation types such as Atriplex vallicola–Lasthenia ferrisiae–Lepidium jaredii association that occurs on vernal alkaline flats, Monolopia stricta association that occurs adjacent to these flats on terraces and slopes, and Monolopia lanceolata association that occurs on higher elevation exposed hillsides up through the Temblor and Caliente Mountains.

Next year, additional staff will delineate the vegetation types throughout the Monument using GIS technology. The final product will be a fine-scale vegetation map, which will help guide long-term management of natural resources throughout the Monument including many rare plants and animals. We look forward to future phases of the project and to being a part of the protection of resources on our public lands.