Carboniferous Vegetation
The Carboniferous period (the second-to-last period of the Paleozoic era) began 359 million years ago and is considered one of the pivotal times in plant history. During this period, many groups of land plants reached their peak development, forming the Earth’s very first highly complex forest ecosystems.
The areas that are now Europe’s coal basins were – back in the Carboniferous – low-lying swamps and lagoons covered in lush, diverse tropical forests rich in different species. These forests included tree-like, spore-bearing plants related to today’s lycophytes and ferns, as well as extinct primitive gymnosperms called seed ferns, cordaites, and earliest conifers. It is these plants ultimately formed the bituminous coal deposits that are now mined in Poland and elsewhere.
In the early Carboniferous, plant life showed limited geographical variation and was fairly uniform across the globe. However, in the late Carboniferous, distinct differences in plant communities began to emerge based on geography, with unique plant provinces forming as climate differences grew more pronounced. The Euramerican province (on what was then the Euramerican continent), the Siberian province, and the Chinese province (on what were then the continents of Angara and Cathaysia) formed in the northern hemisphere, while the southern hemisphere saw the emergence of the Gondwanan province (on the continent of Gondwana).
Europe, along with eastern North America, northern Africa, the Middle East, and the Aral-Caspian region, was then part of the Euramerican province. The Carboniferous flora of this province is among the best understood. Since much of the province lay in an equatorial zone, its climate was likely similar to today’s tropical climates, with high temperature and humidity. The European coal basins of the Carboniferous period were low-lying swamp and lagoon areas covered by dense, species-rich forests. These forests included tree-like spore plants such as lycophytes and ferns, along with primitive gymnosperms like seed ferns and cordaites. The lower layer of the forest featured herbaceous ferns, small lycophytes, horsetails, mosses, and liverworts, along with various climbing ferns and calamites. Gymnosperms like cordaites grew along the swamp edges, with a few primitive conifers appearing on higher ground. These plants did not grow haphazardly mixed together; rather, like modern plants, they had specific preferences for climate, water, and sunlight, forming distinct clusters based on these conditions.