Temperate hardwood deciduous forest is the dominant landcover in the Northeastern US, yet its canopy is usually ignored as pollinator habitat due to the abundance of wind-pollinated trees. We describe the vertical stratification of spring bee communities in this habitat and explore associations with bee traits, canopy cover, and coarse woody debris. For three years, we sampled second-growth woodlots and apple orchard-adjacent forest sites from late March to early June every 7–10 days with paired sets of tri-colored pan traps in the canopy (20–25 m above ground) and understory (<1m). Roughly one fifth of the known New York state bee fauna were caught at each height, and 90 of 417 species overall, with many species shared across the strata. We found equal species richness, higher diversity, and a much higher proportion of female bees in the canopy compared to the understory. Female solitary, social, soil- and wood-nesting bees were all abundant in the canopy while soil-nesting and solitary bees of both sexes dominated the understory. Canopy cover increased with leaf-out, and was negatively associated with understory but not canopy bee abundance. Site-level volume of coarse woody debris (CWD) did not predict bee abundance, while approximated landscape-scale availability of woody debris was positively correlated with understory wood-nesting and solitary-bee abundance. This work expands our understanding of habitats where bees are likely foraging and reveals vertically stratified behavior. We emphasize deciduous forests as an important habitat for wild bee conservation and recommend further research into the behavior and diets of bees occupying the canopy, speculating that females forage for anemophilous tree pollen. Forest management plans that conserve above-ground deadwood may provide nest sites for wood-nesting bees.

温带阔叶落叶林是美国东北部主要的土地覆盖物，但由于风铃树的丰富，通常将其冠层视为传粉媒介的栖息地。我们描述了该栖息地中春季蜜蜂群落的垂直分层，并探讨了与蜜蜂特征，冠层覆盖和粗木屑的关联。三年来，我们从3月下旬至6月初每隔7-10天对次生林地和苹果园附近的森林地点进行采样，并在树冠层（地面20-25 m）中和地下进行成对的三色集水器（<1m）。在每个高度都捕获了大约五分之一的纽约州已知蜜蜂动物群，总共捕获了417种蜜蜂中的90种，并且整个地层共有许多物种。我们发现物种丰富度相同，多样性更高，与林下相比，树冠中的雌蜂比例要高得多。在树冠层中，雌性单亲，社交，土壤和木材嵌套的蜜蜂都丰富，而雌雄两性的土壤嵌套和孤独的蜜蜂占主导地位。冠层覆盖随着叶的散开而增加，与林下但与冠层蜂的丰度没有负相关。现场水平的粗木屑（CWD）不能预测蜂的数量，而木屑的近似景观规模可用性与林下树木的筑巢和孤蜂的数量呈正相关。这项工作扩大了我们对蜜蜂可能觅食的栖息地的了解，并揭示了垂直分层的行为。我们强调落叶林是保护野生蜂的重要生境，并建议进一步研究占据树冠的蜜蜂的行为和饮食，并推测雌性为嗜性树花粉觅食。保护地上枯木的森林管理计划可以为筑巢的蜜蜂提供巢穴。