|
Altered non-native grassland with sparse deciduous trees (13.45 acres)
<br /> This is the largest unit on the property and encompasses everything south of the
<br /> hayfield and within the floodplain ring.This unit is roughly delineated on the north
<br /> side by the band of ash trees that grow along an east/west wet depression (Photo
<br /> 1).The northern portion of the savanna area is relatively open,with a few scattered
<br /> trees. Moving south,the tree cover increases,and clumped stands of oaks and other
<br /> species become more frequent.While the species composition may not reflect a
<br /> typical savanna,the structure is more reflective of a typical oak savanna.
<br /> The grassland is dominated by smooth brome,though occasional native grasses and
<br /> sedges are present.The large bur oaks grouped and scattered throughout the unit
<br /> range in size from 51.4-88.0 cm dbh,and most have large laterally growing branches
<br /> indicative of historically open-grown trees (Photo 2). Other species present include
<br /> cottonwood (97.9 cm dbh),green ash (83.9, 105.7 cm dbh) and,further south, silver
<br /> maple (82.6, 112.0 cm dbh). Invasive shrubs and herbaceous plants are common
<br /> around the bases of these trees,and include species like buckthorn,honeysuckle,
<br /> burdock,and thistles (Photo 3). Siberian elm seedlings are also present on occasion.
<br /> This grassland should be managed as a savanna,and fire must be used to prevent
<br /> further woody encroachment. Native savanna seed should be added post-burns to
<br /> establish cover that will help to compete with the non-native grasses. Small
<br /> diameter trees can also be removed (except for any oaks),to mimic the composition
<br /> and structure of historical savannas. Copses of oaks can also be added if time and
<br /> budget allows.
<br /> - � 0 ,� 1 ?\, . , , „,, 6�,�i�,1 � �I I
<br /> �� �� , ., „ ,, ,, ,, ,1 „ ,:,,, , ,
<br /> -I,, ,.,_.
<br /> ! 1 F ar
<br /> / � 4
<br /> ,,, \ 1,,,
<br /> , , toi.
<br /> tC! �� Kf v� t— r'. x .
<br /> , .. ..2,,i,...,
<br /> �' t � hp,i f! r� �J ,A is
<br /> *. _. ' qty yy •
<br /> R'A'F x ,
<br /> ; �� 't��~ r� AY c jyfk •+. �'�.�. fit. � '�s "'.
<br /> Photo 1. Looking north at the row of ash separating the grassland unit from the
<br /> hayfield/prairie area.
<br /> Friends of the Mississippi River Bailey Point Nature Preserve NRMP
<br /> 34
<br />
|