Comprehensive Evaluation Report

determined not to be at risk. None of the ecosystem characteristics on the Grasslands is projected to trend
away from reference conditions, therefore, it was determined that there are no risks to the ecosystem
diversity on the Grasslands 11 . The Shinnery Oak PNVT is near reference condition, and the remaining
six PNVTs (Mixed Grass Prairie, Pinyon-Juniper, Cottonwood-Willow, Mixed Hardwood Riparian,
Shortgrass Prairie, and Sand sagebrush) are moving towards their reference conditions. The conditions of
the unique habitat features found on the Grasslands (playa lakes, riverine and wetland associations on the
Kiowa and Rita Blanca Grasslands and aquatic or riverine and wetland associated habitats on the Black
Kettle Grasslands) have been dramatically improved, especially compared to the extremely degraded
condition they were in during the 1940s and 1950s following the Dust Bowl era. Given these conditions,
there are no risks to the ecosystem diversity on the Grasslands.
A species risk assessment was conducted by processing each species on the list of Species for Further
Consideration in Cibola Grasslands Plan Revision through an assessment of various habitat and
population factors and threats 12 . Natural history and population information was gleaned from the
references used in the screening process and from Cibola National Grasslands biologists; State of OK,
TX, and NM biologists; and the US Fish and Wildlife Service biologists. The results of this process
provided a numerical ranking of the risk to a species. Those species found to be at high risk were further
assessed for their likelihood of being affected by four population and distribution scenarios. Of the
species identified for further consideration in Plan Revision, lesser prairie-chicken, plains leopard frog,
black-tailed prairie dog, mountain plover, and swift fox were assessed to be at high risk on shinnery oak,
ponds and playa lakes, sand sagebrush, shortgrass prairie, and cottonwood/willow riparian PNVTs
(respectively). The risks to these species were found to be the threats derived from fragmentation, disease,
predation, and invasive species.
Ecosystem Diversity Concern Areas
Due to disruption from settlement and agriculture production on adjacent private lands, the vegetative
characteristics found on the Grasslands are largely unique in comparison to the surrounding landscape.
Because the Grasslands exist to provide for ecological diversity, it is critical that the ecosystem
characteristics contained within them be restored and maintained. There are several areas of ecosystem
diversity concern:
o Four of the seven PNVTs (Shinnery Oak, Pinyon-Juniper, Mixed Hardwood Riparian, and Sand
sagebrush) have a reduced range across the Section and Subsection. Therefore, management of
these vegetation types on the Grassland units is important for the protection of their associated
species.
o Of the seven vegetation types found on the Grasslands, all depart to some degree from their
respective reference condition structure and disturbance regime. The degree of this departure
varies across each of the seven PNVTs.
o The introduction, presence and spread of invasive species have the potential to significantly
modify ecological systems and processes.
o The potential effects of climate change are far-reaching: changes to vegetation structure and
composition, soil condition, and water availability are reasonably foreseeable.
11 In some instances, an ecosystem characteristic (for example, ground water quantity) was identified as being outside of, and trending away
from, its reference condition. However, the causes for this condition and trend were found to be outside of the Forest Service’s control (for
example, due to aquifer drawdown).
12 To assess the habitat, population and threat factors for each species, the Forest Service’s Southwestern Regions’ Ecological Sustainability
guidance was followed and tables were adapted to reflect assessment and ranking processes (Ecological Sustainability Version 5.1,
10/10/2006, Status of Species, Table 6, Table 7).
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