Using site appropriate pioneer species to initiate pedogenic processes which promote recovery to stable and complex forested ecosystems

摘要

Often when working in forest environments the goal of reclamation is to reestablish a stable ecosystem with characteristics similar to the pre-disturbance forest.In northern forests,Pinus species are widely recognized as early seral species but are seldom the species of choice for reclamation.Recent work with lodgepole pine has demonstrated that with the correct symbionts,this species is capable of fixing nitrogen which partially explains why it is the predominant pioneer species in highly disturbed environments within its range.A variety of other physiological characteristics and microbial symbionts facilitate adaptation to highly disturbed environments.In accordance with primary pedogenic principles,biota and environment work together to evolve the soil conditions necessary to support increasingly complex later seral communities.Human intervention to speed up pedogenesis can inadvertently drive soil development towards conditions that are not stable and require continued intervention.Recognizing and using pioneer species such as lodgepole pine,which are adapted to forest environments,allows reestablishment of complex and resilient forest ecosystems with minimal human intervention.We describe characteristics of lodgepole pine which allow it to function as a pioneer species and discuss early uses of direct seeding of lodgepole in reclamation.Pine established from seed develops better root geometry than transplants and is free of nursery adapted microflora.Due to lodgepole pine's high internal cycling of nitrogen,over time soil nutrient capital will build up as long-lived high C/N ratio litter which discourages invasion by weedy species and reduces the likelihood of nitrate assisted cation leaching.A location appropriate vegetative cover can be established from the outset without the difficult changeover in vegetative community that is required when agronomic species are used to establish cover.