[
  {
    "effect_size": null,
    "effect_unit": "",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "Systematic meta-analysis of single-strain EMF inoculation on pine and spruce. 32 growth studies and 26 stress-resistance studies from 1806 records. EMF significantly increased conifer growth; the effect on stress resistance was not statistically significant. Field studies remain scarce.",
    "study_count": 32,
    "comparison_count": null,
    "source_url": "https://doi.org/10.1016/j.foreco.2025.122982",
    "potential_yield_effect": null,
    "geography": "Global Pinus and Picea inoculation trials",
    "intervention": "Single-strain ectomycorrhizal inoculation",
    "comparator": "Non-inoculated conifer seedlings",
    "dose": "",
    "dose_unit": "",
    "limitations": "Abstract does not quote a single percent. Nursery fertilizer can suppress colonization (see Khasa 2001).",
    "source_year": 2025,
    "doi": "10.1016/j.foreco.2025.122982",
    "baseline": "",
    "factor_id": "tree-ecm-growth-meta",
    "crop_id": "tree-seedlings",
    "factor": "Ectomycorrhizal fungal inoculation (Pinus and Picea)",
    "factor_category": "Biological inputs",
    "direction": "positive",
    "effect_type": "yield_gain",
    "evidence_type": "meta_analysis",
    "evidence_strength": "High",
    "prairie_relevance": "high",
    "source_title": "Ectomycorrhizal fungi inoculation of conifers increases growth, but not stress resistance: A meta-analysis (Rwizi, Čėsna, Krokene & Mageroy 2025)",
    "notes": "Growth (nursery or early field biomass/height) is the supported outcome. Do not claim drought or pest resistance from this meta-analysis. Strain × host matching matters."
  },
  {
    "effect_size": 29.0,
    "effect_unit": "% gross total volume",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "Boreal Ontario. Greenhouse inoculation with native ectomycorrhizae. Jack pine on dry, nutrient-poor sites: crop-tree density +17%, basal area +26%, gross total volume +29% versus non-inoculated, driven by early survival rather than larger individual trees (QMD and height NS). Black spruce on mesic sites: +12–13% stand metrics, not significant.",
    "study_count": 1,
    "comparison_count": null,
    "source_url": "https://doi.org/10.5558/tfc2026-015",
    "potential_yield_effect": 29.0,
    "geography": "Boreal Ontario plantations (jack pine dry sites; black spruce mesic)",
    "intervention": "Hebeloma spp. greenhouse inoculation",
    "comparator": "Non-inoculated nursery stock",
    "dose": "",
    "dose_unit": "",
    "limitations": "Ontario, not Alberta. Black spruce response was weak. Quadratic mean diameter did not differ.",
    "source_year": 2026,
    "doi": "10.5558/tfc2026-015",
    "baseline": "",
    "factor_id": "tree-jack-pine-hebeloma-25yr",
    "crop_id": "tree-seedlings",
    "factor": "Nursery Hebeloma inoculation of jack pine (25-year stand outcome)",
    "factor_category": "Biological inputs",
    "direction": "positive",
    "effect_type": "yield_gain",
    "evidence_type": "long_term_trial",
    "evidence_strength": "High",
    "prairie_relevance": "high",
    "source_title": "Can greenhouse inoculation with native mycorrhizae improve planted jack pine and black spruce survival and growth? A 25-year retrospective assessment (2026)",
    "notes": "Closest long-term analogue for Prairie/boreal reforestation stock. Benefit is stand stocking/survival on poor sites, which is the FMA contract metric."
  },
  {
    "effect_size": null,
    "effect_unit": "",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "Container Pinus contorta, Picea glauca, Picea mariana and bareroot pine/larch inoculated with six ECM species at three fertilizer levels. Seedling growth rose with fertilizer; authors concluded fertilizer could be cut up to 33% with selected fungi without sacrificing growth. Hebeloma, Laccaria bicolor, Paxillus involutus, and Pisolithus formed well-developed ECM; Rhizopogon vinicolor and Suillus tomentosus did not.",
    "study_count": 1,
    "comparison_count": null,
    "source_url": "https://doi.org/10.1023/A:1015674921878",
    "potential_yield_effect": null,
    "geography": "Alberta / Québec nursery experiments (University of Alberta co-authors)",
    "intervention": "ECM inoculation at reduced fertilizer",
    "comparator": "Higher fertilizer without effective ECM",
    "dose": "",
    "dose_unit": "",
    "limitations": "Nursery growth, not outplanting survival, is the primary result of the 2001 paper. Fungus identity is not interchangeable.",
    "source_year": 2001,
    "doi": "10.1023/A:1015674921878",
    "baseline": "",
    "factor_id": "tree-khasa-container-ecm-alberta",
    "crop_id": "tree-seedlings",
    "factor": "Selected ECM fungi with reduced nursery fertilizer (Alberta container stock)",
    "factor_category": "Nutrients",
    "direction": "positive",
    "effect_type": "other",
    "evidence_type": "greenhouse_trial",
    "evidence_strength": "High",
    "prairie_relevance": "high",
    "source_title": "Effect of fertilization on growth and ectomycorrhizal development of container-grown and bare-root nursery conifer seedlings (Khasa et al. 2001)",
    "notes": "Follow-up outplanting in northern Alberta (Quoreshi & Khasa 2006, CJFR 10.1139/x06-063) found only Laccaria bicolor still detectable after 5–6 years; some inoculation treatments still differed in plot volume index."
  },
  {
    "effect_size": null,
    "effect_unit": "",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "2023 Alberta greenhouse survey. Tree-seedling houses had the highest average investment cost ($478.16/m²) and among the higher gross returns per m² (second to lettuce). Contracts are typically FMA / seed-zone certified stock, not spot retail.",
    "study_count": 1,
    "comparison_count": null,
    "source_url": "https://open.alberta.ca/dataset/fbb2b0b5-53b9-4dbd-92b7-f37ec8ed9369/resource/f4313ce0-1ea0-45e0-bc34-18306b1d2128/download/agi-economics-production-marketing-greenhouse-crops-2023.pdf",
    "potential_yield_effect": null,
    "geography": "Alberta",
    "intervention": "Observed tree-seedling enterprise",
    "comparator": "Other Alberta greenhouse crops",
    "dose": "",
    "dose_unit": "",
    "limitations": "Survey. Specification premiums are not itemized.",
    "source_year": 2025,
    "doi": "",
    "baseline": "",
    "factor_id": "tree-agriprofits-seedlings",
    "crop_id": "tree-seedlings",
    "factor": "Alberta AgriProfit$ 2023 tree-seedling investment and returns",
    "factor_category": "Economics & Certification",
    "direction": "positive",
    "effect_type": "other",
    "evidence_type": "economic_benchmark",
    "evidence_strength": "High",
    "prairie_relevance": "high",
    "source_title": "Economics of Production and Marketing of Greenhouse Crops in Alberta 2023 (Laate)",
    "notes": "Profit is contract price × spec (height, RCD, freeze hardiness, seedlot). ECM and hardening affect spec and survival more than nursery biomass alone."
  },
  {
    "effect_size": null,
    "effect_unit": "",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "White spruce seedlings: photoperiod controls shoot and root frost tolerance and bud phenology (Bigras & D'Aoust 1993, CJFR). Short days in late summer are the commercial blackout method to set buds before freezer storage. This remains a quantified-effect-size gap for Picea glauca / Pinus contorta Alberta stock — include as a directional, high-relevance practice with primary-study follow-up required.",
    "study_count": 1,
    "comparison_count": null,
    "source_url": "https://doi.org/10.1139/x93-029",
    "potential_yield_effect": null,
    "geography": "Canadian container nursery (white spruce)",
    "intervention": "Short-day / blackout photoperiod",
    "comparator": "Long-day growing photoperiod",
    "dose": "",
    "dose_unit": "",
    "limitations": "Frost tolerance and bud phenology, not nursery height. Do not report a fabricated % yield.",
    "source_year": 1993,
    "doi": "10.1139/x93-029",
    "baseline": "",
    "applicability": "direct",
    "evidence_tier": "B",
    "factor_id": "tree-photoperiod-frost-white-spruce",
    "crop_id": "tree-seedlings",
    "factor": "Short-day photoperiod to induce bud set and frost hardiness (white spruce)",
    "factor_category": "Climate",
    "direction": "positive",
    "effect_type": "other",
    "evidence_type": "greenhouse_trial",
    "evidence_strength": "High",
    "prairie_relevance": "high",
    "source_title": "Influence of photoperiod on shoot and root frost tolerance and bud phenology of white spruce seedlings (Bigras & D'Aoust 1993)",
    "notes": "Protocol gap preserved: pooled % survival or RGP for lodgepole and white spruce blackout is still not extracted here. Direction is strongly positive for storage survival, which is the saleable unit."
  },
  {
    "effect_size": null,
    "effect_unit": "",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "High-throughput phenotyping of Scots pine seedling provenances under drought (Evolutionary Applications 2025). Seedlot choice is a yield/survival factor after outplanting. Not a greenhouse kg/m² factor.",
    "study_count": 1,
    "comparison_count": null,
    "source_url": "https://doi.org/10.1111/eva.70157",
    "potential_yield_effect": null,
    "geography": "Scots pine seedling provenances",
    "intervention": "Drought-adapted provenance",
    "comparator": "Other provenances",
    "dose": "",
    "dose_unit": "",
    "limitations": "Pinus sylvestris, not P. contorta. No single % quoted here.",
    "source_year": 2025,
    "doi": "10.1111/eva.70157",
    "baseline": "",
    "applicability": "mechanistic",
    "evidence_tier": "B",
    "factor_id": "tree-scots-pine-drought-provenance",
    "crop_id": "tree-seedlings",
    "factor": "Provenance / genetic variation in seedling drought response (Scots pine)",
    "factor_category": "Genetics",
    "direction": "context_dependent",
    "effect_type": "other",
    "evidence_type": "greenhouse_trial",
    "evidence_strength": "Moderate",
    "prairie_relevance": "moderate",
    "source_title": "Drought Response and Genetic Variation in Scots Pine Seedlings' Provenances (2025)",
    "notes": "Genetics cell of the crop × factor matrix. Transfer to Alberta lodgepole/jack pine is mechanistic, not direct."
  }
]