Fertilization impacts on Swiss needle cast disease severity in western Oregon

Mulvey, Robin L.; Shaw, David C.; Maguire, Douglas A.

doi:10.1016/j.foreco.2012.08.050

Cited by 9 publications

(12 citation statements)

References 24 publications

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“…The foliar and bolewood Ca concentrations across our sites were at the low end of reported values for Douglas-fir in the Pacific Northwest (Walker and Gessel 1991, Binkley et al 1992, Homann et al 1994, Cross and Perakis 2011, and the three highest-soil-N sites possessed foliar Ca concentrations at or below deficiency levels (Walker and Gessel 1991). We also found that aboveground productivity increased as N accumulated to roughly the mid-point of our soil N gradient, then plateaued or declined thereafter (Table 1), raising the possibility that Ca depletion exacerbates the impacts of foliar pathogens in suppressing forest growth on the most N-rich sites (Mulvey et al 2013). Ongoing fertilization experiments in coastal Oregon forests show that Ca can limit growth of Douglas-fir on high-N sites, with growth response related to background Ca:N ratios in soil (D. B. Mainwaring, D. A. Maguire, and S. S. Perakis, unpublished manuscript).…”

Section: Discussionmentioning

confidence: 51%

“…It is likely that high N conditions across our gradient impaired the foraging ability of roots and mycorrhizae due to diminished plant C allocation belowground (Dybzinski et al 2011). This may be intensified in western Oregon Douglas-fir by native pathogenic fungi on high-N sites (Mulvey et al 2013;Luoma and Eberhart, in press), consistent with declines in plant Ca concentrations and pools at high-N sites. Low plant Ca availability can also directly reduce C allocation to roots and mycorrhizae, which may further impede plant Ca uptake from soil (Schulte-Baukloh and Fromm 1993).…”

Section: Discussionmentioning

confidence: 74%

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Forest calcium depletion and biotic retention along a soil nitrogen gradient

Perakis

Sinkhorn

Catricala

et al. 2013

Ecological Applications

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High nitrogen (N) accumulation in terrestrial ecosystems can shift patterns of nutrient limitation and deficiency beyond N toward other nutrients, most notably phosphorus (P) and base cations (calcium [Ca], magnesium [Mg], and potassium [K]). We examined how naturally high N accumulation from a legacy of symbiotic N fixation shaped P and base cation cycling across a gradient of nine temperate conifer forests in the Oregon Coast Range. We were particularly interested in whether long-term legacies of symbiotic N fixation promoted coupled N and organic P accumulation in soils, and whether biotic demands by non-fixing vegetation could conserve ecosystem base cations as N accumulated. Total soil N (0-100 cm) pools increased nearly threefold across the N gradient, leading to increased nitrate leaching, declines in soil pH from 5.8 to 4.2, 10-fold declines in soil exchangeable Ca, Mg, and K, and increased mobilization of aluminum. These results suggest that long-term N enrichment had acidified soils and depleted much of the readily weatherable base cation pool. Soil organic P increased with both soil N and C across the gradient, but soil inorganic P, biomass P, and P leaching loss did not vary with N, implying that historic symbiotic N fixation promoted soil organic P accumulation and P sufficiency for non-fixers. Even though soil pools of Ca, Mg, and K all declined as soil N increased, only Ca declined in biomass pools, suggesting the emergence of Ca deficiency at high N. Biotic conservation and tight recycling of Ca increased in response to whole-ecosystem Ca depletion, as indicated by preferential accumulation of Ca in biomass and surface soil. Our findings support a hierarchical model of coupled N-Ca cycling under long-term soil N enrichment, whereby ecosystem-level N saturation and nitrate leaching deplete readily available soil Ca, stimulating biotic Ca conservation as overall supply diminishes. We conclude that a legacy of biological N fixation can increase N and P accumulation in soil organic matter to the point that neither nutrient is limiting to subsequent non-fixers, while also resulting in natural N saturation that intensifies base cation depletion and deficiency.

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Section: Discussionmentioning

confidence: 51%

Section: Discussionmentioning

confidence: 74%

Forest calcium depletion and biotic retention along a soil nitrogen gradient

Perakis

Sinkhorn

Catricala

et al. 2013

Ecological Applications

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“…The epidemic is also correlated with the intensification of Douglas-fir plantation management from the 1960's to 1990's, and the conversion of mixed western hemlock, Douglas-fir, Sitka spruce, red alder, and western redcedar stands to young monocultures of Douglas-fir [1]. Fertilization appears to have no effect on disease severity [27]. Although there have been no published accounts, it appears that disease is not as severe within old-growth Douglas-fir crowns, perhaps due to vertical diversity of microclimate and foliage nutrition.…”

Section: Discussionmentioning

confidence: 99%

Swiss Needle Cast in Western Oregon Douglas-Fir Plantations: 20‐Year Monitoring Results

Ritóková

Shaw

Filip

et al. 2016

Forests

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Swiss needle cast (SNC), a foliar disease specific to Douglas-fir (Pseudotsuga menziesii), is caused by an endemic Ascomycete fungus (Phaeocryptopus gaeumannii). In the late 1980s and early 1990s significant symptoms began to appear in coastal Oregon, and these have been associated with the planting of Douglas-fir in the Sitka spruce zone, leaf wetness during potential spore dispersal in May-August, and mild winter temperature. The first annual aerial survey was initiated in 1996 and has continued through 2015, which indicates a significant increase in area of visible symptoms from the air, increasing from 53,050 ha in 1996 to 238,705 ha in 2015. Monitoring plots in the NW Oregon Coast Range verified impacts of SNC on tree growth and productivity, with growth reductions averaging about 23% in the epidemic area linked to needle retention. A series of monitoring plots was set up in the western Cascade Mountains of Oregon and 590 10-23-year old Douglas-fir trees in 59 stands were tracked for 10 years, measured in 2001, 2006, and 2011. No measureable growth impacts were noted in this region of Oregon. A new plot network is being installed throughout the Oregon and southwest Washington coastal ranges as a means of monitoring future disease impact and providing framework for additional studies.

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“…La fertilización se ha usado para controlar la enfermedad. El exceso de N incrementa la severidad del tizón suizo (El-Hajj et al, 2004), y en balance con P no la incrementa (Mulvey et al, 2013); y acículas sanas en proporción al N, tienen baja dosis de P (Mohren et al, 1986). El silicio (Si) + micronutrients with 250 and 1000 ppm of Si, indicated that these formulations may contribute to eventual control of P. gaeumannii.…”

Section: Revista Mexicana De Fitopatologíaunclassified

“…Fertilization has been used to control the disease. The excess N increases the severity of Swiss needle cast (El-Hajj et al, 2004), and balanced with P, it does not increase it (Mulvey et al, 2013); and healthy needles in proportion to N have low P doses (Mohren et al, 1986). Silicon (Si) has not been used to control Swiss needle cast.…”

Section: Revista Mexicana De Fitopatologíamentioning

confidence: 99%