s Research~No#e~“’

1981

Flooding, Beavers, and Hardwood Seedling Survival

R. M. Krinard and R. L. Johnson

SUMMARY

Plantings were made for three successive years

on clay-capped soils in the Mississippi River batture,

the first year without flooding, and the second and

third years with flooding. Species planted, but not

in all years, were eastern cottonwood (Populus

deltoides Bartr. ex Marsh.), sycamore (Platanus

occidentalis L.), green ash (Fraxinus pennsylvanica

Marsh.), sugarberry (Celtis /aevigata\Willd.), sweetgum (Liquidambar styraciflua, L.), swamp chestnut oak (Quercus michauxii Nutt.), Shumard oak

(Quercus shumardii Buckl.), and sweet pecan (Carya

iliinoensis, Wangenh., K. Koch). In years with flooding,

beaver pulled up a fourth of the newly planted seedlings and ate the root systems. Height after 3 years,

for trees planted in the first flood-free year, varied

from 2.2 feet (sweet pecan) to 40.5 feet (cottonwood),

arid survival varied from 63 percent (cottonwood) to

97 percent (green ash). Species planted in years

‘with flooding, omitting beaver-destroyed trees, had

better than 70 percent survival except for Shumard

oak, swamp chestnut oak, and sweetgum.

Additional keywords: Populus deltoides, Piatanus

occidentalis, Fraxinus pennsyivanica, Celtis iaevigala, Liquidambar styracifiua, Quercus michauxii,

Quercus shumardii, Carya iiiinoensis.

INTRODUCTION

Without adverse factors, survival of planted hardwood seedlings is usually adequate. However, flooding and animal damage may be very detrimental.

This note provides information on hardwood survival

for three successive years, the first without and the

second and third with flooding and beaver problems.

METHODS

In 1977, a study was established on cleared

ground in the Mississippi River batture at Ajax Bar

in lssaquena County, Mississippi, to test and compare survival and growth of several commercial

hardwood species after planting. Soils were Bowdre

series on the high ridges and Tunica series on

the low ridges and flats. Both soils had clay caps

overlying loamy material, with a texture change

occurring within the top 10 to 20 inches for Bowdre

and within 20 to 48 inches for Tunica. The first

planting was done in January and Febrliary 1977

and included nine plots each of sweetgum, sweet

pecan, swamp chestnut oak, green ash and sugarberry, two plots of sycamore, and one of cottonwood.

Plots were 22 rows of 22 trees, with the interior

12 rows of 12 trees being measurement plots.

Spacing was 12 by 12 feet. The second planting,

in February 1978, included nine plots.of sweetgum,

six plots of sweet pecan, ten plots of green ash,

19 plots of Shumard oak, two plots of sycamore,

and one plot of cottonwood. Also, skips in the 1977

sweet pecan planting were sown with seed. The

third planting, in January and February 1979, was

a replanting or filling in of the green ash, sweetgum,

and sweet pecan plots planted in 1978 along with

nine of the Shumard oak plots and six new swamp

chestnut oak plots.

Between April 20 and 26,1978, seedlings planted

in 1977 and 1978 were examined and tallied as to

condition.’ Sweet pecan and swamp chestnut oak

*Seedling condition classes were: dead, dormant, leafed out,

dead or living leaves which had been water covered, beaver

damaged, and missing.

Southern Forest Experiment Station/T-10210 U.S. Postal Services Bldg., 701 Loyola Avenue, New Orleans, La. 70113

Forest Service, U.S. Department of Agriculture.

Serving Alabama, Arkansas, Louisiana, Mississippi, Eastern Oklahoma, Tennessee, Eastern Texas.
seedlings plantedlin 1977 were re-examined in,May,

and four Shumsrd oak~~plots were re-examined- in

May, June,, bid~Jyi&:r~ ,:

Seedlingsptant&d iti t:Q79 were examined the first

week of June or in mid-July 1979.

Heights were measured after the 1977,1978, and

1979 growing seasons.

RBSULTS

Flooding

Extent of flooding of plotswas based on Mississippi

River stage readings at Vicksburg, Mississippi, about

42 miles downstream from Ajax. With the river on a

rise, backwater from an adjacent slough to the north

of the study area began entering the planting at 32

feet (Vicksburg river stage). Flood stage at Vicksburg was 43 feet.

In 1977, the maximum river stage was 33.7 feet

in April and water was not a problem.

In 1978, the river su eet on March 24,

continued rising t0.a c feet on April 11,

then fell, but remalned above 32 feet through April ’ 25. A seco&f~‘rise’was above 32 feet on May 10,

crested at 37.4 feet on May 26, and then fell back

to 32 feet on June 6. At the high water mark of

40 feet, only three spots (about 19 percent of the

planting area) were not inundated. .

Time between the water’s receding in April to

flooding again in. May ver,ied from 17 to 36 days.

Plots with 16 days or less of total flooding (tables

1 and 2) were only flooded in April; plots with 24

days of flooding were flooded 18 days in April and

6 days in May; and plots with 48 days of flooding

were flooded 27 days in April and 21 days in May.

In 1979, the river passed32 feet on March 3 and

did not return to that mark until June 13. By March

12, the water was already higher than it had gotten

in 1978! and water stayed above that level until.

May 19. The crest was 47.9 feet from April 26

through 29.

Table 1 .-Number d days plots flooded, by maximum, intermediate, and minimum time intervals, and average

height and survival of trees planted in 1977

Species Flood No. No. days water Survival Average height

class plots on plots1

1978 1979 1977 1978 1979 1977 1978 1979

Max.

Mid.

Min.

Max.

Mid.

Min.

Max.

Mid.

Min.

Max.

.Mid.

Min.

Max.

Mid.

Min.

Max.

Min.

2 4 8 9 5 7 5 71

8 28/383 84188 81 77

1 2 4 8 3 81 8 0

1 3 3 8 8 Qc 8 4

5 8128 74184 77 8 2

3 0 8 7 7 9 8 9

3 24 83 9 6 9 5

3 12 7 8 9 7 9 7

3 8 7 4 9 7 9 7

3 2 4 8 3 9 0 8 9

3 12 7 8 8 8 8 8

3 8 7 4 8 8 8 8

1 2 4 8 3 8 9 7 8

5 8/13 74/78 9 0 8 5

3 0 8 7 8 9 8 7

1 0 8 5 9 8 9 6

1 0 5 2 9 4 9 4

1 0 5 2 8 8 8 4

_______ percent _______ --------Feet--------

Sweetgum

Sweet pecan2

Green ash

Sugarberry

Swamp chestnut oak

Sycamore

Cottonwood

Walues represent plot averages

*Missing planting spots seeded after 1977 growing season.

aRange of days flooded between intermediate plots.

8 2

72

7 9

8 5

8 0

81

9 8

9 7

9 7

8 9

8 8

8 8

2

8 7

9 8

9 4

8 3

1.3 2.4 3.6

1.4 2.4 4.2

1.3 2.7 4.6

0.4 1.1 1.7

0.5 1.2 2.0

0.5 1.5 2.8

5.3 9.3 -13.2

4.9 9.2 13.4

5.7 9.9 14.1

3.9 5.6 7.8

3.8 6.1 8.2

3.8 6.1 8.2

1.1 1.8 1.9

1.4 2.2 2.7

1.5 3.6 5.0

8.9 14.0 22.0

8.0 12.3 18.4

9.7 23.7 40.5

R. M. Krinard is Mensurationist and R. L. Johnson is Principal Silviculturist at the Southern Hardwoods Laboratory, maintained at

Stoneville, Mississippi, by the Southern Forest Experiment Station, Forest Service-USDA, in cooperation with the Mississippi

Agricultural and Forestry Experiment Station and the Southern Hardwood Forest Research Group.

2
.I Beaver Damage

The first inkling of beaver damage came while

observing the area at the high water mark in April

1978. Apparently staying in shallow water, the beaver

grasped a. newly-planted seedling about 3 to 4

inches above the ground, as indicated by teeth

marks on the stem, pulled the seedling from the

ground, ate the root system to about the root collar,

and then dropped the stem at the planting site

(fig. 1). Long rows of consecutively damaged trees

were observed.

When damage to the seedlingswasfirstdiscovered,

samples of the cut-off stems were sent to four wildlife

experts for examination. The unanimous evaluation

was that beaver, rather than nutria, were responsible

for the problem.

Beavers were generally not discriminating, destroying seedlings of all species. A possible exception was sycamore. Location of the sycamore plots

could have been a factor, as adjacent Shumard oak

plots were not as heavily damaged as oak plots in

another area.

Beavers only destroyed seedlings adjacent to the

rising or falling water line. They did not damage trees

on unflooded ridges that were only 5 to 10 feet

from the water line. Beaver damage occurred with

both floods in 1978, but did not occur after the

water receded in May. The beaver returned with the

flood waters in 1979, and again destroyed newlyplanted seedlings.

Seeding Survival

During 1977, seedlings were not flooded’and

there was no beaver damage. First-year survival

ranged from 86 percent for cottonwood to 97 percent for green ash (table 1). Average total heights

were between 0.5 feet (sweet pecan) and 9.7 feet

(cottonwood).

In 1978, l-year-old trees of all species had some

foliation at the April flood. Most trees of green ash

and sugarberry were tall enough to be above the

floodwaters even though the water was 4% feet deep

in drains (fig. 2). About half the l-year-old swamp

chestnut oak and sweet pecan and all the sweetgum

seedlings were submerged. Sycamore and cottonwood were not flooded.

Of the newly planted trees, 31 percent of the

sweetgum, 36 percent of the cottonwood, and 81

percent of the sycamore had leafed out before the

April flood. Less than 10 percent of the Shumard

Table 2.--Number of days plots flooded, by maximum, intermediate, and minimum time intervals, and average

height and survival of trees planted in 1978 and 1979

Species Flood No.

class plots

No. days water

on plots’

1978 1979

Survival Average height

1978 1979 1978 1979

Sweetgum

Sweet pecan2

Green ash2

Shumard oak3

Swamp chestnut oak4

Sycamore.

Cottonwood

Max. 3

Mid. 3

Min. 3

Max. 3

Min. 3

Max. 4

Mid. 4

Min. 2

Max. 4

Mid. 1 1

Min. 4

Max. 1

Mid. 4

Min. 1

2

1

485

1 8/24e

1 1

8

0

486

13132

6

3 2

13120

8

956

80183

7 6

7 2

6 7

956

78186

7 0

. . . . .

. . . . .

. . . . .

. . . . . . 9 0

. . . . . . 8 3

,..... 7 8

2 0 8 2

2 4 8 3

----Percent----

6 0 8 7

2 4 4 3

3 5 4 8

4 3 5 1

6 0 7 3

7 3 8 2

5 2 7 5

5 0 7 4

0 . . . .

9

3 2 ::::

. . . . 1 6

. . . . 2 7

. . . . 4 2

9 4 9 4

7 2 7 2

_ ___ _ Feet-_ ___

1.0 1.4

1.1 1.3

1.2 1.4

0.6 0.9

0.6 1.1

2.6 5.4

2.4 4.6

3.1 5.4

‘di’ : : : :

1.0 . . . .

. . . . 0.6

. . . . 0.6

. . . . 0.7

3.0 7.8

6.5 12.2

Values represent plot averages.

2Missing planting spots replanted after 1978 growing season.

3Not measured after 1979 growing season.

‘Planted prior to 1979 growing season.

6Trapped water remained on portions of plots for more days than shown after flood receded.

Wange of days flooded between intermediate plots.

3
Figure 1 .-Beaver-damaged green ash seedling with root system missing and bark peeled from the base of

the stem.

oak seedlings were starting to leaf out when the water

covered them. Sweet pecan and green ash leafed

out above the water or soon after the water receded.

After the April 1978 flood, trees (of all species)

which had been in the field a year retained healthy

leaves which had emerged or remained above the

flood waters. Newly-planted sweetgums, which had

been submerged for 21 days, started leafing out

almost immediately while Shumard oaks, which had

been submerged from 13 to 21 days, were showing

bud swell and a few small leaves.

The May 1978 rise covered all l-year-old sweetgum plots, one-third of the sweet pecan, green ash,

and sugarberry plots, and three-fourths of one

swamp chestnut oak plot. Except for a few swamp

chestnut oaks and sweet pecan, l-year-old seedlings were not submerged by the May flood.

The May overflow covered some of the same

newly-planted Shumard oaks, sweetgumsand green

ash that had been flooded in April. Shumard oaks

appeared to have not recovered from the April

flood as they had small, chlorotic-appearing leaves

and buds which had stopped elongating. Sweetgums had leafed out between floods, but most green

ash were still dormant.

After water receded in May, new sweetgum which

had been defoliated for a second time, again put

out new leaves within 2 to 3 weeks. Green ash

seedlings put out initial leaves about 2 weeks after

the May flood.

Survival of trees planted in 1978 and subjected to

flooding, compared to first-year survival of the floodfree 1977 planting (eliminating beaver-removed

trees), was similar for sycamore, cottonwood, and

sweet pecan and 25 percent lower for green ash

and sweetgum.

The species hurt most by flooding was Shumard

oak (table 2). Number of dead Shumards doubled

by the end of June, then doubled again by mid-July.

Only 11 percent of the trees survived in flooded

areas. On a few dry ridges, 50 percent of the

trees lived.

Beaver destroyed 24 percent of the trees planted

in 1978. By species, from 1 percent of the sycamore

to 39 percent of the sweetgum were lost (table 3).

Less than 50 of all trees planted in 1977 were

damaged by beaver. They were cut within 2 feet of

the ground, but resprouted after the water left.

In 1979 the plots were covered with water from

52 to 95 days (tables 1 and 2). Most trees had

4
’ Table 3.-Seedling survival and destruction by beaver for 1978

and 1979 plantings or replantings

Species

1978 1979

Beaver Beaver

Surviva’ destroyed Surviva’ destroyed

----------------percent----------------

Sweetgum 4 0 3 9 5 3 2 4

Sweet pecan 5 2 3 1 6 2 2 6

Green ash 6 0 1 5 7 8 1 8

Shumard oak 1 2 2 4 2 4 3

Swamp chestnut oak 1 1 2 8 9

Sycamore 9 4 1 1 1

Average, yearly second- and third-year growth

varied from approximately 1 foot for sweet pecan,

swamp chestnut oak, and sweetgum to 2 feet for

sugarberry, to 4 feet for green ash, to 7 feet for

sycamore. Cottonwood grew 14 feet in the second

year and 17 feet in the third year.

‘Not planted.

*Not measured because of very low survival. DISCUSSION AND CONCLUSIONS

not leafed out before being inundated. Survival of

newly-planted swamp chestnut oak seedlings was

only 28 percent.

Beaver destroyed 25 percent of the trees on plots

which had been either replanted or newly-planted.

For the plots originally planted in 1978, tree

height growth and survival are confounded with

beaver destruction and replanting to the extent that

the value of such figures are questionable. The

following results pertain only to the 1977 planting.

Trees planted during the first flood-free year

seemed little affected by floods during the second

and third year. There was practically no mortality

of cottonwood, sycamore, green ash, and sugarberry. Sweetgum and swamp chestnut oak lost 3 to 5

percentage points each year with greatest losses

in the longest-flooded plots (table 1). Sweet pecan

survival could not be evaluated because missing

spots after 1 year had been direct-seeded.

Flooding had a slight effect on growth within a

species. Trees flooded the longest grew less than

trees on higher plots except for sycamores, which

were on a higher site. However, growth differences

were only a foot or less for all species except swamp

chestnut oak.

One growing season without flooding would be

most desirable in establishing hardwood plantations.

Even the Shumard oak might have been able to

tolerate the floodwaters had they been established

for a year. This is based on Shumard which was

planted along the Mississippi River and survived the

1973 and 1975 floods. However, if first-year flooding

is a probability, then green ash and sycamore should

be favored in planting because of their survival

and growth characteristics.

On Sharkey clay soil, Baker (1977) observed firstyear survival of 90 percent for sycamore and green

ash, 80 percent for sweetgum, and only 20 percent

for cottonwood where plantings were completely

covered by water for 4 weeks in May. This was a

ponded water rather than a flowing water situation.

Other planting tests involving sweet pecan, sweetgum, green ash, sycamore, and cottonwood on

Figure 2.-Flood waters beginning to recede from green ash trees starting their second growing season

(April 1978).

5
Sharkey clay and Commerce silt loam (unpublished

data) in Mississippi have demonstrated the same

order of growth between species after 3 years as

at Ajax, but magnitude of growth within species

differed by sites.

The beaver problem could be much more serious

than water. It is the first time, to our knowledge, that

‘beavers have actually pulled seedlings out of the

ground and destroyed the roots. Only newly-planted

trees would be affected, but it happens so quickly

and extensively, that complete destruction of a

large-scale planting is entirely possible. Cutting of

2- or 3-year-old trees is not a major problem, since

nearly all our hardwoods will resprout and likely

2Persona1 correspondence with Dr. James B. Baker, U.S. Forest

Service, Monticello, Ark., July 22, 1980.

lose very little growth (unless it occurs several

years in succession);

The apparent lack of interest by beavers for sycamore, at least where other species are present, has

been observed elsewhere. In an informal planting

study in Coahoma County, Mississippi, beavers cut

off nearly every cottonwood in most plots but did not

bother any sycamore seedlings in adjacent plots.2

LlTBRATlJlPB CITED

Baker, James B.

1977. Tolerance of planted hardwoods to spring

flooding. South. J. Appl. For. 1(3):23-25.

6