In the north-west of Castrop-Rauxel, north of the Rhine-Herne Canal, there is a wooded open space complex with a larger excavation site and an extensive wetland area that was created by subsidence and is divided into various sub-areas by roads.
Southwest of Pöppinghausen lies the structurally rich forest area of the Nettheide, characterized by a near-natural oak-beech hall forest with little undergrowth with only a few developed herb layers, alternating with pure oak forests with a densely developed herb layer (from locally dominant blackberries with bracken herds and carpets from the lawn smithy. In the center To the south and south-east of Pöppinghausen, birch, oak and beech forests grow at groundwater sites, supplemented by a swampy alder floodplain forest.
Along the Rhine-Herne Canal, extensive subsidence area with open water areas, extensive gray willow bushes, sedge and reed beds. The willow bushes are locally towered over by young, dying or already dead birches. The forested area of Döninger Heide in the east is now extensively covered by relatively sparse birch-oak forests, which grow on groundwater-near, e.g. T. probably also standing in waterlogged locations. The structurally rich biotope complex as a whole is a relatively near-natural, structurally rich refuge for animal and plant species in the forests and wetlands within the metropolitan area. The occurrence of large stocks of the water feather, bank sedge and roller sedge within the subsidence area is floristically remarkable.
The forest and wetland biotope complex Nettheide-Döninger Heide is a central biotope element between the biotope axes of the Emscher middle course in the north and the Rhine-Herne Canal in the south. The adjacent Rhine-Herne Canal is a technical waterway, but it also serves as a guideline and orientation for many waterfowl.
The central objective of nature conservation should be the preservation and expansion of quiet, undisturbed forest and water biotopes up to natural forests.