Marbled Murrelet Effectiveness Monitoring Plan For The Northwest Forest Plan

Author : Teresa J. Lorenz
Publisher :
ISBN 13 :
Total Pages : 64 pages
Book Rating : 4.:/5 (128 download)

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Download or read book Status and Trend of Nesting Habitat for the Marbled Murrelet Under the Northwest Forest Plan, 1993 to 2017 written by Teresa J. Lorenz and published by . This book was released on 2021 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The objectives of the effectiveness monitoring plan for the marbled murrelet (Brachyramphus marmoratus) include mapping nesting habitat at the start of the Northwest Forest Plan (NWFP) and estimating changes in that habitat every 5 years. Using Maxent species distribution models, we modeled the amount and distribution of probable nesting habitat in the murrelet's range in the NWFP area in 1993, 1 year prior to the start of the NWFP, and 25 years later (2017). Within the higher probability nesting habitat, we then estimated the amount of contiguous habitat (core) versus the amount of habitat bounding core habitat(edge) and habitat scattered in small forest fragments (scatter). We considered this "core habitat" as the best habitat. Our models indicate that there were 1.51 million acre of higher probability nesting habitat over all lands in the murrelet's range in Washington, Oregon, and California 1 year prior to the start of the NWFP in 1993. Of this, 0.14 million acre were identified as core habitat, which we defined as intact patches of higher probability nesting habitat>5.56 acre in size. In core habitat, we expected nest predation to be relatively low and the microclimate most favorable for murrelets. Most (68 percent, or 1.04 million acre)higher probability nesting habitat in 1993 was on federally administered lands, with 0.97 million acre (66 percent) in reserved land use allocations. We estimated that non-federal lands contained 29 percent of all higher probability nesting habitat, but only 13 percent of all core habitat. Thus, the bulk of core habitat was on federal lands. We estimated a net loss of about 1.4 percent in higher probability nesting habitat across the NWFP area and 1.8 percent in core habitat from 1993 to 2017. Timber harvest and wildfire were the major causes of habitat loss on federal lands since the NWFP was implemented. Timber harvest was the primary cause of loss on state and other nonfederal lands, accounting for 99 percent of all attributable losses since 1993. The NWFP has been successful in conserving higher probability nesting habitat on federal lands across the NWFP area, but has been less successful in conserving core habitat. We anticipate that losses of habitat on federal lands will continue because of fires and timber harvest. As forests mature, some of these losses maybe exceeded by recovery of currently unsuitable habitat within reserves. However, climate change offers a very real threat, and thus many gains may not be realized as the climate in the NWFP area becomes warmer, drier, and less favorable for developing forest conditions necessary for nesting murrelets. In addition, because losses of nesting habitat continue on private lands, incentives are needed to curb losses to better meet conservation objectives."--Page iii