Tiering on Land – Trees and Forests (Late Palaeozoic)

Abstract

The first regional‐scale forests appeared in mid‐Carboniferous times, c . 325 million years ago (Ma). Known as the coal swamps, they extended over large parts of tropical Pangaea and lasted for about 40 million years. The dominant plants of the swamps were arborescent lycopsids, sphenopsids, ferns, pteridosperms and cordaitanthales. Many were very fast‐growing plants and resulted in thick peat deposits being formed, which have subsequently changed into economically important coals. Changes in the geographical extent of these tropical swamps correlated with the waxing and waning of the Late Palaeozoic Ice Age polar ice sheet, and the carbon sequestration caused by the swamps may have been affecting global climates. The development of the swamps coincided with a major global diversification in insects and may also have been home to some early terrestrial amphibians and reptiles. Key Concepts The coal swamps were the first regional‐scale forests to occur on Earth. The swamps occupied a broad belt of land in palaeotropical Pangaea during the late Carboniferous and early Permian (325–275 Ma). They were responsible for one of the highest rates of terrestrial carbon sequestration in Earth history. The size of the coal swamps was correlated with climate fluctuations during the Late Palaeozoic Ice Age. Insects and possibly of tetrapod vertebrates diversified during the time of the coal swamps.

Macrofloral biostratigraphy reflects late Carboniferous vegetation dynamics in the Nord‐Pas‐de‐Calais Coalfield, France

“…The history of the coal swamps can be broadly broken down into four phases (Cleal & Thomas 1999, 2005Cleal 2021aCleal , 2021b): an early phase of 'proto-coal swamps' in the early Namurian (e.g. Purky nov a 1970; Gastaldo et al 2009aGastaldo et al , 2009bStrullu-Derrien et al 2021); a Westphalian phase represented by the major Carboniferous coalfields of Euramerica, and representing the first major glacial phase of the Late Palaeozoic Ice Age; a Stephanian interglacial phase mainly seen in the intramontane basins of Europe and the paralic basins of the southern foreland of the Variscan Orogen; and a Cisuralian (early Permian) phase seen in the Cathaysian coalfields mainly of China, and representing the second major glacial phase of the Late Palaeozoic Ice Age.…”