CHAPTER 1I: APPROACH AND METHODS 44
consider for wildlife conservation. These units are based primarily on physical features and/or plant
assemblages and are considered communities when animal assemblages are attributed to them. We have
attempted to use recognizable, “standard” terms when referring to these habitats to be consistent with
other planning efforts.
Environmental attributes such as water, soil type and the structure and composition of vegetation not
only help define habitat types and their importance and usage by species, but also strongly influence
community structure. Typically the change from one ecological community type to another occurs as
environmental characteristics change to the extent that a large number of species drop out of an
assemblage. Species composition is associated with environmental attributes of a community.
Community composition may also change due to management treatments unrelated to habitat that favor
some species over others.
HABITAT CONDITION
Management practices and the history of disturbance are important factors that affect the types and
conditions of wildlife habitats. Returning Mississippi to conditions occurring prior to European
settlement is not a goal of this strategy, nor is it possible. Little has been written about conditions of the
Central Gulf Coastal Plain prior to European settlement. We do not know, with any real confidence
what those conditions were and human activity over the past 200 years has dramatically altered the
natural landscape. However, understanding the conditions for which wildlife species are adapted and
changes that have occurred to the landscape allow us to better understand why some species have
declined. This is useful when planning and implementing habitat-based actions to alleviate problems.
Often one must approximate historical conditions to help understand species composition today.
Evidence suggests that the state was once covered with mostly unbroken stands of deciduous, mixed
pine-hardwood and evergreen forests. As a result of naturally occurring fires and fires used by Native
Americans as a management tool, these forests were composed of large well-spaced trees and supported
an ample ground cover of herbs and shrubs.
Centuries of land clearing and development have changed Mississippi’s natural landscape. Forests are
now more fragmented and dense, with reduced tree diversity, age, species composition and size.
Consequent to the changes in forest density and age, diversity and productivity of understory vegetation
has likely been significantly reduced. In addition, numerous exotic species (terrestrial and aquatic), some
of which are especially aggressive and detrimental to native species, have been introduced and some
now thrive.
Pre-settlement aquatic systems were likely cooler, clearer and contained less nutrients and toxins than
today. Stream channels were generally narrower, stable and meandering, with lower gradients and water
velocities. Urbanization and modern agricultural practices have increased levels of nutrients and toxins,