Vegetation Sampling & Mapping in Castle Mountains National Monument

Joshua Tree (Yucca brevifolia) woodland
Fig. 1 Joshua Tree (Yucca brevifolia) woodland with various perennial grasses in the understory in the western lowlands of the Castle Mountains NM. The brilliant Cooper’s goldenbush (Ericameria cooperi) was in full bloom during the CNPS visit.

In the far northeast corner of the Mojave National Preserve, nestled between the Castle Peaks of the New York Mountains and the Piute Mountains, the Castle Mountains appear more modest than their neighbors. However, upon closer look at this mountain chain and its surrounding lowlands this spring, the CNPS Vegetation Program staff found a treasure trove of plant diversity. This attribute was one of many that motivated President Barack Obama to proclaim the area as a National Monument (NM) on February 12, 2016.

Managed by the National Park Service through the Mojave National Preserve, the Castle Mountains now fall within the scope of a vegetation mapping effort for the Mojave Desert Inventory and Monitoring Network (MOJN), to which the CNPS Vegetation Program has been contributing valuable data and input since 2010 and earlier. During the first week of May 2016, four CNPS vegetation ecologists set out with the goal of surveying the plant communities found there. Over the course of a week, we roamed across the cardinal regions of the area, from the (still active) mining sites to the rocky crags to the luscious bajadas covered in Joshua tree woodlands spilling out into the Lanfair Valley and the rest of the Mojave Preserve.

The surveys gathered during this expedition track some of the common vegetation types found in this area and repeating in the landscape–Joshua tree woodland (Yucca brevifolia), Mojave yucca shrubland (Yucca shidigera), and blackbrush shrubland (Coleogyne ramosissima)– as well as more uncommon types such as extensive James’ galleta shrub-steppe (Pleuraphis jamesii) and a rare burrograss grassland stand (Scleropogon brevifolius). The Castle Mountains generally are celebrated for their desert grasslands, including sprawling swathes of galleta grasses (Pleuraphis spp.) beneath majestically large Joshua trees. Plot data was gathered following the standard sampling protocols established by the National Vegetation Mapping Program and will contribute to MOJN project. This project, which began in 2009, is working to create accurate vegetation maps and classification for the Mojave National Preserve, Death Valley National Park, Lake Mead Recreation Area, and now the Castle Mountains NM, for the sake of informing ongoing conservation and management efforts.

The Castle Mountains are a beautiful and important addition to our nation’s monuments. Throughout the week, the breathtaking views of a thriving desert ecosystem with an abundance of plant diversity reminded us of the continued imperative to preserve our wild landscapes, to which our native plants and plant communities are foundational.

A barrel cactus
Fig. 2 A barrel cactus (Ferocactus cylindraceus) amidst blooming Englemann’s hedgehog cactus (Echinocereus engelmannii) and Eastern Mojave buckwheat (Eriogonum fasciculatum); nested within a Utah juniper (Juniperus osteosperma) woodland stand.

A Mojave yucca
Fig 3 A Mojave yucca (Yucca shidigera) shrubland stand on the eastern side of the Castle Mountains.

Two color beardtongue
Fig 4 Two color beardtongue (Penstemon bicolor) blooming at the edge of a four-wing saltbush (Atriplex canascens) shrubland stand in a disturbed southern area of the mountains, where mining has been active since the turn of the 20th century.

Joshua tree with Spanish bayonet
Fig 5 Joshua tree (Yucca brevifolia) with Spanish bayonet (Yucca baccata) on the Castle’s western slopes. Two other shrubs in bloom during the CNPS trip are pictured here: Desert purple sage (Salvia dorrii) and apricot mallow (Sphaeralcea ambigua).

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