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<br />Attendant base level lowering and channel incision may tend to reduce <br />lateral availability of moisture for plant maintenance. <br />Additionally, it is not known what effect the subsidence wave would have <br />on streamside substrate bearing wetland vegetation. Abrupt tilting could <br />destabilize channel forks and aggravate bank sloughing. <br />Over the long-term, channel configuration and sites available for <br />vegetation establishment would likely assume characteristics similar to <br />present via erosional processes. Although incorporation of this lease <br />with WF-U's LHU would increase Red Wash involvement by 50 percent, the <br />ultimate affect relative to the extent of Red Wash currently subject to <br />subsidence would be negligible. <br />Direct removal of .palustrine vegetation could occur during mechanized <br />channel work proposed by WF-U to maintain uninterrupted flow to the White <br />River. Channel response to subsidence should be evaluated to determine if <br />such work is necessary or prudent. <br />Wildlife <br />No long-term or major impacts to terrestrial habitats (e.g., mule deer) <br />are expected. Subsidence is expected to occur as a gradual, more or less <br />uniform lowering of the land form--formation of extensive or conspicuous <br />surface irregularities (e.g., shears of slippage) is not predicted. Small <br />areas of surface disturbance associated with well pad construction, or <br />subsidence (e.g., tension cracks) would eventually assume the character of <br />adjacent habitats via weathering, natural plant reestablishment, or proper <br />reclamation practices. <br />Possible short-term reductions in obligate palustrine components (e.g., <br />tamarisk) due to subsidence (see Vegetation section) would not be expected <br />to prompt redistribution or displacement of common riparian associates due <br />to the extremely limited extent of disturbance and rapid regenerative <br />capacity of wetland habitats. However, passing of a subsidence wave could <br />topple senescent cottonwoods in the vicinity of the lease and represent a <br />loss of cavity or tree nesting habitat for species such as the kestrel and <br />red-tailed hawk. <br />Burrow or den-dwelling animals would be most susceptible to habitat loss <br />or mortality. It is conceivable that subterranean burrow systems or dens <br />could become damaged or destroyed from surface flex as a subsidence wave <br />passes. In the experience of local BLH and USFWS personnel, prairie dog <br />populations and, ostensibly, their burrows remain unaffected when <br />subjected to slight upheavals from seismic exploration activities, but it - - <br />is unknown if these burrows would be capable of retaining structural <br />integrity during subsidence. The degree of impact on individual animals <br />would be dependent on variables such as timing of active subsidence, <br />burrow depth, soil strength, and extent of burrow damage. Presumably, <br />mature animals would readily escape from partially collapsed burrows or <br />dens; dependent young of such species nesting or denning at the time of <br />active subsidence would be most susceptible. <br /> <br />15 <br />