The importance of integrating ecological and genetic approaches in - PowerPoint PPT Presentation

Forest tree species restoration – where and why. The importance of integrating ecological and genetic approaches in forest ecosystem science Patricia Maloney 1 , Detlev Vogler 2 , Camille Jensen 1 , Annette Delfino Mix 2 , Andrew Eckert 3 , David Neale 4 1 University of California – Davis, Department of Plant Pathology & Tahoe Environmental Research Center 2 USDA Forest Service, PSW Research Station, Institute of Forest Genetics 3 Department of Biology, Virginia Commonwealth University 4 Department of Plant Sciences, University of California – Davis

Forest restoration versus Species restoration • Restore population numbers – • Prescription burning, facilitate recruitment thinning • Enhance genetic diversity • Structural shifts (mixed size structure) • Deploy disease resistance (if warranted) • Compositional shifts • Deploy drought tolerant phenotypes

Sugar pine restoration • Extensive logging and fire suppression policies have changed the structure & composition in lower montane forests (Lindstrom et al. 2000; Manley et al.2000). • Historical composition : 20 – 25%, in some locations (Lindstrom et al. 2000) . • Present – day composition : 1 – 6% (Barbour et al. 2002; Lindstrom et al. 2000) . • Population & genetic consequences : Effects on population structure and dynamics, but also genetic structure and diversity. Population and genetic losses. • Non-native pathogen introduction : Cronartium ribicola , cause of white pine blister rust (WPBR) • Such losses could affect sugar pine’s resilience to disturbances and environmental change (e.g., WPBR, MPB, climate).

Sugar pine restoration – Where? • Sugar Pine Point State Park • Tunnel Creek – Sand Harbor • Granlibakken – 3rd candidate site

Sugar pine restoration – Why? • Reduced population sizes  = 0.993  = 1.048 Density = 14 inds. ha -1 50 Density = 95 inds. ha -1 Sugar Pine State Park 50 Recruitment = 128 (inds. ha -1 ) 45 Bliss State Park 45 Recruitment = 262 (inds. ha -1 ) 40 WPBR = 41% ( Cr1 = 0.12) Low lambda (  ) – low 40 • WPBR = 5% ( Cr1 = 0.07) 35 35 30 30 survival of small – and 25 25 20 20 15 15 intermediate – sized individuals 10 10 5 5 0 0 ³40.1 ³40.1 0.1-5.0 5.1-10.0 10.1-20.0 20.1-40.0 0.1-5.0 5.1-10.0 10.1-20.0 20.1-40.0 Diameter size class (cm dbh) Diameter size class (cm dbh) • Low recruitment  = 0.997  = 0.994 50 Density = 37 inds. ha -1 (inds. ha -1 ) 50 Granlibakken 45 Density = 16 inds. ha -1 Tunnel Creek 45 Recruitment = 25 40 Recruitment = 10 (inds. ha -1 ) 40 WPBR = 48% ( Cr1 = 0.00) • 35 WPBR = 11% ( Cr1 = 0.00) High levels of WPBR 35 30 30 25 25 20 20 15 15 10 10 • 5 5 Low frequency of Cr1 0 0 ³40.1 0.1-5.0 5.1-10.0 10.1-20.0 20.1-40.0 ³40.1 0.1-5.0 5.1-10.0 10.1-20.0 20.1-40.0 Diameter size class (cm dbh) Diameter size class (cm dbh)

Sugar pine restoration, cont. Consequences of historical logging • High genetic drift in some populations • Effects of genetic drift are greater in small populations • In small populations drift can act faster to reduce genetic variation

Sugar pine restoration strategies Sugar Pine Point SP Tunnel Creek/Sand Harbor • Increase population size • Facilitate recruitment • Deploy WPBR resistance • Increase sugar pine (≤ 0.20) numbers – population size • Enhance genetic diversity • Enhance genetic diversity

Western white pine restoration – Where? • Blackwood Canyon

Western white pine restoration – Why? • Highest disease pressure by WPBR in upper montane forests – 44% • Moderate levels of MPB – 15% • Relatively low mean survivorship across diameter classes (0.833), with the lowest for trees 5.1 – 10.0 cm dbh (0.700) • Most mesic upper montane location in study – Average annual ppt = 1472 mm 1.Mesic adapted? 2. Favorable conditions for WPBR infection

Western white pine restoration, cont. 1.000 0.980 0.960 0.940 0.920 0.900 0.880 0.860 0.840 0.820 0.800 0 10 20 30 40 50 Incidence of WPBR (%) WPBR is known to be a predisposing agent to MPB attack 180 Western White Pine Size Structure at Blackwood Canyon 160 140 1.000 120 0.980 0.960 100 0.940 0.920 80 0.900 60 0.880 WPBR = 44% 0.860 40 0.840 0.820 20 0.800 0 5 10 15 20 25 30 0 ³40.1 Incidence of Mountain Pine Beetle (%) seedlings 0.1-5.0 5.1-10.0 10.1-20.0 20.1-40.0 Size class

Western white pine restoration strategies at Blackwood Canyon • A diversity of seedling material will be planted as well as WPBR – resistant genotypes – to increase small tree survival ( Cr2 is found in WWP at 2 locations in the Lake Tahoe Basin – Armstrong Pass and Meiss Meadow). • Given the local environmental conditions at Blackwood Canyon the tree species here may be more mesic-adapted and less drought tolerant than species growing in more xeric conditions (i.e., east side locations, granitic soil types). • Next year common garden studies will be completed for WWP and drought tolerant families & populations will be identified. Out – planted seedlings will include drought tolerant phenotypes.

Whitebark pine restoration – Where? • Rifle Peak area – Ridge from Mt Baldy, Rifle Peak to east of Rose Knob Peak

Whitebark pine restoration – Why? • Very high disease pressure by WPBR – 65% • Most critical effect of WPBR is infection and mortality of cone-bearing branches. • Low cone production and recruitment Photo: Cheryl Beyer

Whitebark pine restoration, cont. 5000 R 2 = 0.78, P = 0.003 4000 • Negative relationships between cone production and 3000 WPBR incidence and severity. 2000 1000 • Percent of individuals infected (incidence), average 0 0 10 20 30 40 50 60 70 number of infected branches per population, and severity WPBR incidence (%) of stem girdling are all negatively related with cone production. 5000 R 2 = 0.72, P = 0.008 4000 • Whitebark pine at Rifle Peak has the lowest female cone 3000 numbers [960 cones ha -1 (mean across sites = 2,456)], 2000 lowest recruitment numbers [44 seedlings/saplings ha -1 1000 0 (mean across sites = 139)], and the highest incidence of 0 1 2 3 4 5 6 WPBR (65%) of all whitebark pine populations surveyed Average number of branch cankers per tree in the Lake Tahoe Basin. 5000 R 2 = 0.76, P = 0.005 • A threshold number of ≥ 1,000 cones ha -1 has been 4000 estimated to maintain seed dispersal within a forest stand 3000 by Clark ’ s nutcracker (McKinney et al., 2009). Whitebark 2000 pine cone production at Rifle Peak falls below this 1000 threshold. 0 0.00 0.25 0.50 0.75 1.00 1.25 1.50 Average stem girdle category population -

Whitebark pine restoration strategies • Facilitate whitebark pine recruitment to maintain adequate species numbers • Deploy WPBR resistant and/or tolerant phenotypes • Diverse seedling material Photo: Martin Frye

Testing white pine restoration protocols • Will use 2-year old seedlings • Planting season (spring vs fall) • Microhabitat (closed canopy, open canopy, log/litter debris, rock shelter) • Protective enclosures (above and belowground herbivore pressure)

Acknowledgements • Tom Burt, Martin Frye • CA State Parks: Tamara Sasaki, Rich Adams • LTBMU: David Fournier, Cheryl Beyer, Joey Keeley • NDF & NV State Parks: Roland Shaw, Bill Champion • Funding sources: • Southern Nevada Public Lands Management Act – Sponsored by the USDA FS Pacific Southwest Research Station • NVDSL Lake Tahoe License Plate Program