ABSTRACT The northern Rocky Mountain Trench of eastern British Columbia is a broad valley mantled by glaciolacustrine terraces supporting a complex mix of mesic-temperate (“interior wet belt”) forests that are strongly affected by terrain and substrate. Neither the geomorphic history during early Holocene deglaciation nor the vegetation history of the origin of the Tsuga heterophylla (western hemlock) and Thuja plicata (western redcedar) populations in the interior wet-belt forest is well understood. Sediment cores were obtained from two lakes, 10 km apart and occupying different terraces (83 m elevational difference), and these were compared to existing fire-history and paleoclimate reconstructions. Radiocarbon dates and a mapped terrain classification indicate the upper terrace formed as a lacustrine and glaciofluvial kame terrace hundreds of years prior to the lower terrace, which was formed by glaciolacustrine sediments of a proglacial lake. The minimum limiting ages of these terraces correlate with dated jökulhlaup deposits of the Fraser River. The upper site’s first detectable pollen at >11.0 ka was dominated by light-seeded pioneer taxa (Poaceae [grasses], Artemisia [sagebrush], and Populus [aspen]) followed by a peak in Pinus (pine) and finally dominance by Betula (birch) at 10.2 ka. Pollen data suggest an earlier invasion of T. heterophylla (western hemlock) (by ca. 8 ka) than previously understood. Wetlands on extensive, poorly drained, glaciolacustrine soils promoted the persistence of boreal taxa and open forests (e.g., Picea mariana [black spruce]), while the better-drained upper kame terrace promoted development of closed-canopy shade-tolerant taxa. Invasion and expansion of mesic cedar-hemlock taxa progressed since at least the middle Holocene but was highly constrained by edaphic controls.

Abstract A Late Cretaceous (Campanian) leaf megaflora from the Vomb Trough in southern Skåne, Sweden, has been investigated on the basis of collections held at the Swedish Museum of Natural History. The main plant-bearing locality is Köpinge, but single specimens originate from Högestad, Ingelstorp, Rödmölla, Svenstorps mölla and Tosterup. The fossil flora is dominated by the angiosperm (eudicot) Debeya ( Dewalquea ) haldemiana (Debey ex de Saporta & Marion) Halamski. Other dicots are cf. Dryophyllum sp., Ettingshausenia sp., Rarytkinia ? sp., Dicotylophyllum friesii (Nilsson) comb. nov. and Salicites wahlbergii (Nilsson) Hisinger. Conifers are represented by cf. Aachenia sp. (cone scales), Pagiophyllum sp. and Cyparissidium sp. (leaves). Single poorly preserved specimens of ferns and monocots have also been identified. The terrestrial palynomorphs (the focus herein) clearly link to the megaflora, although with different relative abundances. The fern spore Cyathidites dominates along with the conifer pollen Perinopollenites elatoides and Classopollis . Angiosperm pollen comprise up to 15% of the assemblage, represented by monocolpate, tricolpate and periporate pollen and the extinct Normapolles group. The spores in the kerogen residue show a thermal alteration index (TAI) of 2+. The flora probably represents mainly a coastal lowland Debeya /conifer forest, and is similar to approximately coeval assemblages from analogous palaeo-communities described from eastern Poland, western Ukraine and Westphalia.