Effects of Age, Stand Density, and Fertilizer Application on Bear Oak Reproduction -

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Effects of Age, Stand Density, and Fertilizer Application on Bear Oak Reproduction Author(s): Leonard J. Wolgast and Benjamin B. Stout Source: The Journal of Wildlife Management, Vol. 41, No. 4 (Oct., 1977), pp. 685-691 Published by: Wiley on behalf of the Wildlife Society Stable URL: https://www.jstor.org/stable/3799990 Accessed: 01-11-2023 18:39 +00:00 REFERENCES Linked references are available on JSTOR for this article: https://www.jstor.org/stable/3799990?seq=1&cid=pdf-reference#references_tab_contents You may need to log in to JSTOR to access the linked references. JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at https://about.jstor.org/terms Wiley, Wildlife Society are collaborating with JSTOR to digitize, preserve and extend access to The Journal of Wildlife Management This content downloaded from 73.84.198.143 on Wed, 01 Nov 2023 18:39:35 +00:00 All use subject to https://about.jstor.org/terms EFFECTS OF AGE, STAND DENSITY, AND FERTILIZER APPLICATION ON BEAR OAK REPRODUCTION LEONARD J. WOLGAST, Department of Horticulture and Forestry, Cook College, Rutgers University, New Brunswick, New Jersey 08903 BENJAMIN B. STOUT, Department of Biological Sciences, Rutgers University, New Brunswick, New Jersey 08903 Abstract: Bear oak (Quercus ilicifolia) is widely distributed in the northeastern and mid-Atlantic states. It grows on poor sites where its acorns are important in the diets of many wildlife species. Mature acorns were first produced by bear oak sprouts 3 growing seasons old. Stand density, at the levels measured in this study, had relatively little effect on the acorn production. Fertilizer application and age interacted significantly (P < 0.05) in their influence on acorn yields. Addition of 896 kg/ha of 5-10-5 applied in late March resulted in increased production of pistillate flowers, immature acorns, and mature acorns in 9-year-old and 13-year-old trees, but had relatively little influence on 5-year-old trees. J. WILDL. MANAGE. 41(4):685-691 Bear oak occurs from southern Maine,The overstory vegetation on the study New York and Pennsylvania, south toarea is exclusively pitch pine (Pinus West rigida). Virginia, western North Carolina, and Vir-The understory is primarily bear oak with ginia (Little 1953:332). This species oc-much lesser amounts of dwarf curs on acid, rocky or sandy, sterile chinkapin soils, oak (Quercus prinoides) and especially on dry sandy barrens andblackjack rocky oak (Quercus marylandica). The hillsides, from sea level to about 900m shrub and herb layer contains highbush (Society of American Foresters 1967:20). blueberry (Vaccinium corymbosum), low- Wild turkeys (Meleagris gallopava), ruffedbush blueberry (Vaccinium vacillans) and grouse (Bonasa umbellus), bobwhite quailaromatic wintergreen (Gaultheria procum- ( Colinus virginianus), gray squirrels (Sciu-bens). Occasional seedlings of sassafras rus carolinensis), white-tailed deer (Odo-(Sassafras albidum), black oak (Quercus coileus virginianus) and black bears ( Ursusvelutina) and red maple (Acer rubrum) americanus) feed extensively on bear oakare also present. Since acorns are a highly acorns. In addition, the acorns also are uti-concentrated food, bear oak may play a vital role in wildlife nutrition on the area. lized by many nongame birds, particularly jays and woodpeckers (Edminster 1947:Better than normal white-tail fawn produc- 128, Martin et al. 1951:309, Van Dersal tion and antler development are associated 1938:211). with years of high acorn yields. In years The infertile soils of the outer coastal of poor acorn crops, many 1.5 year old plain do not produce a variety of high bucks do not grow antlers large enough to quality foods for wildlife. Bear oak isallow im- legal harvest (R. C. Lund, personal portant throughout the whole coastal communication). plain The importance of bear physiographic province (Widmer 1964: oak acorns in the diet of south Jersey deer has 91), in which over half of New Jersey's been discussed by Little et al. (1958: for- 17-22) est is located, but is especially important on and McDowell (1975:19). the two-thirds of that province knownThe as objective of this study was to deter- the outer coastal plain. This paper mine dealsthe influence of age, stand density, with management of bear oak for and acorn fertilizer application on flowering, fruit production on the outer coastal plain.set, and fruit development in bear oak. J. Wildl. Manage. 41 (4):1977 685 This content downloaded from 73.84.198.143 on Wed, 01 Nov 2023 18:39:35 +00:00 All use subject to https://about.jstor.org/terms 686 AGE, DENSITY, AND FERTILIZER EFFECTS ON BEAR OAK* Wolgast and Stout Table 1. Analysis of variance of numbers of pistillate METHODS flowers-May, 1970. A major source of variation in acorn pro- Source of duction in bear oak was on a tree-to-tree variation df M.S. ( X 10) F P and stand-to-stand rather than a regional Total 47 basis (Wolgast 1972:23-27). Therefore, our Age 2 4.314 4.31 <0.05 experiments were conducted at a single Density 3 2.532 2.53 location within the outer coastal plain Fertilizer in 1 2.014 2.01 A x D 6 1.073 1.07 southern New Jersey. A x F 2 4.663 4.66 <0.05 Sprouts resulting from clear cuts wereD X F 3 0.426 0.43 AX DX F 6 1.242 1.24 used to ascertain the earliest age at which Replicates 24 1.001 acorns are produced. Two 0.005-ha plots in a 10-year-old mixed stand were clear cut during the winter of 1969. The stands on ber of fully developed acorns in all 48 the plots were comprised mostly of bear during the falls of 1970 and 1971. (4) oak and dwarf chinkapin oak. total weight of mature acorns produc In a separate experiment to test the ef- each plot during the fall of 1971. These fects of age, stand density, and fertilization data were treated by the appro ate on mast production, we used a full factorial analysis of variance. design (3 x 4 x 2) with replication. In RESULTS each of 3 age-classes of clumps at the start of the experiment, 16 0.01-ha plots were In the first experiment flowers appeared on bear oak sprouts at the beginning of the thinned to 1 of 4 levels of stand density and one-half of these plots were fertilized. At second growing season, indicating that the start of the experiment (fall of 1969) floral morphogenesis took place during the clumps were 5, 9, and 13 years old. The initial season. These plants produced 5,193 immature acorns on 166 clumps contain- stand densities after an initial thinning were 2,500-3,700 clumps/ha, 3,900-4,800 ing 1,333 stems with a crown area of ap- clumps/ha, 4,700-5,100 clumps/ha, and proximately 0.004 ha. There ultimately de- veloped 808 mature acorns in 1972. The 5,500-6,600 clumps/ha. The fertilized plots first mast crop therefore is produced after received 896 kg/ha of 5-10-5 fertilizer dur- ing the last week of March 1970, 1971, and 3 growing seasons. Little et al. (1958:20) 1972. The fertilizer had a minimum guaran- reported mature acorns on bear oak sprouts 3 teed analysis of 5 percent nitrogen, 10 per- or 4 years old. cent available phosphoric acid as P205, andThe first response measured in the sec- 5 percent soluble potash as K20. In those ond experiment was the 1970 production of pistillate flowers. Significant effects of age plots receiving fertilizer, the fertilizer was scattered evenly over the entire plot. and of age x fertilizer interaction are in- The following responses were measured: dicated (P < 0.05, Table 1). The nature of (1) The number of pistillate flowers this on interaction is depicted in Fig. 1. each of 2 clumps selected at random within The 1971 pistillate flower data were col- each of the 48 plots during May of 1970. lected 1 full year after the first fertilization. Flowers were counted on these same There were significant (P < 0.05) effects of clumps in 1971. (2) The total number of age by fertilizer interaction, and fertilizer, age by immature acorns in all 48 plots during thedensity interaction (Table 2). The falls of 1970 and 1971. (3) The totalmiddle num-aged trees responded best in terms J. Wildl. Manage. 41(4):1977 This content downloaded from 73.84.198.143 on Wed, 01 Nov 2023 18:39:35 +00:00 All use subject to https://about.jstor.org/terms AGE, DENSITY, AND FERTILIZER EFFECTS ON BEAR OAK - Wolgast and Stout 687 Fertilized xN 14C Fertilized N Unfertilized i-- Unfertilized w .lo W e u- 81 ijj i!1i zC 2 ui "fI sI- w IA y " 5 9 13 AGE in years Fig. 1. Number of pistillate flowers produced in 1970 in- 5 9 13 cluding the 95 percent confidence intervals. AGE in Fig. 2. Numbers of pistillate flowers produced in 1971 in- of female flower production after 2 seasonscluding the 95 percent confidence intervals. of fertilizer application (Fig. 2). The higher 2 densities responded better to ferti- lizer than the lower 2 densities (Fig. 3).counts can have been influenced only by Fertilizer was applied before the 1971 the effects of fertilizer on shoot elongation, flower buds were initiated during the late although this response was not measured. The 1971 flower counts were also affected spring of 1970. The differences in flower numbers between 1970 and 1971 data were probably due to this fact. The 1970 flower Fertilized .' Unfertilized m' Table 2. Analysis of variance of numbers of pistillate flowers-May, 1971. Z 100 Source of variation df M.S. ( X10) F P o 60 Total 47 w Age 2 1.020 1.04 Density 3 0.845 0.86 Fertilizer 1 7.579 7.75 <0.05 A X D 6 1.103 1.13 3100 4350 4900 6050 A x F 2 4.152 4.25 <0.05 D X F 3 3.456 3.54 <0.05 Density in Clumps p AX DX F 6 0.812 0.83 Fig. 3. Numbers of pistillate flowers produced in 1971 in- Replicates 24 0.977 cluding the 95 percent confidence intervals. J. Wildl. Manage. 41(4):1977 This content downloaded from 73.84.198.143 on Wed, 01 Nov 2023 18:39:35 +00:00 All use subject to https://about.jstor.org/terms 688 AGE, DENSITY, AND FERTILIZER EFFECTS ON BEAR OAK *Wolgast and Stout Table 3. Analysis of variance of numbers of immature Table 4. Analysis of variance of numbers of immature acorns-Fall, 1970. acorns-Fall, 1971. Source of Source of variation df M.S. ( X106) F P variation df M.S. (X107) F P Total 47 Total 47 Age 2 12.504 2.40 Age 2 19.241 9.16 <0.05 Density 3 6.144 1.18 Density 3 3.897 1.85 Fertilizer 1 6.580 1.26 Fertilizer 1 27.251 12.94 <0.01 A X D 6 2.571 0.49 A X D 6 1.019 0.48 A x F 2 27.607 5.31 <0.05 A x F 2 11.040 5.24 <0.05 D x F 3 0.863 0.17 D X F 3 1.582 0.75 AX DX F 6 2.719 0.52 AX DX F 6 2.069 0.98 Replicates 24 5.201 Replicates 24 2.106 x fertilizer by elongation in addition to the number of interaction (Table 4 flower buds initiated. again (Fig. 5) it was apparent tha The numbers of immature acorns pro-oaks responded more positively duced in 1970 showed a significant age xyounger age class. fertilizer interaction (Table 3). This (Fig. The density x fertilizer interacti 4) was similar to the 1971 pistillate flower was present when these immatur data (Fig. 1). The numbers of immaturewere flowers (Fig. 3) was no longer acorns in 1971 showed that there is a highly significant age effect and a significant age Fertilized ' - 26 Unfertilized M - 2 Fertilized -- Unfertilizedin- 22 6 1aJ16 Z" e 14 1 5 9 13 5 9 13 AGE in AGE years Fig. 4. Number of immature acorns produced in 1970 in- Fig. 5. Numbers of immature acorns produced in 1971 in- cluding the 95 percent confidence intervals. cluding the 95 percent confidence intervals. J. Wildl. Manage. 41(4):1977 This content downloaded from 73.84.198.143 on Wed, 01 Nov 2023 18:39:35 +00:00 All use subject to https://about.jstor.org/terms AGE, DENSITY, AND FERTILIZER EFFECTS ON BEAR OAK* Wolgast and Stout 689 Table 5. Analysis of variance of number of mature acorns- Table 6. Analysis of variance of numbers of mature acorns- Fall, 1970. Fall, 1971. Source of Source of variation df M.S. (X10) F P variation df M.S. (X106) F P Total 47 Total 47 Age 2 88.829 9.13 <0.01 Age 2 6.288 1.61 Density 3 3.159 0.53 Density 3 7.033 1.79 Fertilizer 1 0.320 0.03 Fertilizer 1 6.956 1.77 A x D 6 3.514 0.36 A x D 6 1.585 0.40 A x F 2 17.833 1.83 A X F 2 20.080 5.11 <0.05 D X F 3 16.038 1.65 D x F 3 1.762 0.45 Ax DX F 6 15.618 1.60 A X D X F 6 2.731 0.69' Replicates 24 9.733 Replicates 24 3.933 cant. The greater number of pistillate (Table 5, flow- Fig. 6), similar to that ers at the higher 2 densitieslate in fertilized flowers and immature acorns. These plots may not have been pollinated as readi- mature acorns were immature at the time ly as the fewer numbers of flowers present of the first fertilizer application. No age x in the unfertilized plots at these 2 densities, fertilizer interaction was expected since the or the flower result may have been number of due flowerto buds initiated and the Type I error (Sokal and Rohlf 1969:156). pollination success were complete before A comparison of Figs. 4 and 5 fertilizer illustrates the was applied. The numbers of ma- relative sizes of the 1970 and 1971 imma- ture acorns produced in 1971 show a sig- ture acorn crops. The mean number of im-nificant age x fertilizer interaction (Table mature acorns per 0.01-ha plot irrespective 6). It was the only significant effect (Fig. of treatment in 1970 was 3,932, whereas7). in Comparison of Figs. 7 and 4 indicates 1971 it increased to 12,674. that, as expected, this interaction was very The number of mature acorns produced similar to that with regard to the produc- in 1970 indicated a significant age effect tion of immature acorns. Differences would 200 I,) z g 7 Fertilized VAl o Unfertilized 8 2 2L 25 5 9 13 AGE in years AGE in y Fig. 6. Numbers of mature acorns produced in 1970 in- Fig. 7. Numbers of mature acorns produced in 1971 in- cluding the 95 percent confidence intervals. cluding the 95 percent confidence intervals. J. Wildl. Manage. 41(4):1977 This content downloaded from 73.84.198.143 on Wed, 01 Nov 2023 18:39:35 +00:00 All use subject to https://about.jstor.org/terms 690 AGE, DENSITY, AND FERTILIZER EFFECTS ON BEAR OAK" Wolgast and Stout Table 7. Analysis of variance of weights of mature acorns-- Fertilized %- Fall, 1971. Unfertilizedm-- Source of variation df M.S. F P ) 7 Total 47 Age 2 28.75 1.09, 0 o ' w Density 3 44.40 1.69 Fertilizer 1 100.22 3.82 A x D 6 10.97 0.41 A X F 2 118.42 4.51 <0.05 D X F 3 14.13 0.53 S4 AX DX F 6 20.41 0.77 Replicates 24 26.21 J 3 . 0 have occurred only if the varying treat- z ments exerted their influence on the pro- portion of immature acorns which devel- oped into mature acorns. w The 1971 weights of mature acorns 5 9 13 showed a significant age x fertilizer inter- AGE in action (Table 7) very similar to that for Fig. 8. Kilograms of mature acorns produced in 1971 in- 1971 mature acorn numbers (Fig. 7). Com- cluding the 95 percent confidence intervals. parison of Figs. 7 and 8 indicates that the fertilized acorns in all age classes tended to based on immature acorn counts, this weigh more than an equal number of un- fertilized acorns. In the 1971 mature acorn should be even greater after 2 growing sea- sons and 2 March applications of fertilizer. crop 69,129 acorns produced by unfertilized Differences in the total weight of mature trees weighed 74.31 kg (930 acorns/kg), acorns were even greater than differences whereas 87,402 acorns produced by ferti- lized trees weighed 105.52 kg (828 acorns/ in the total numbers produced. Several re- kg). searchers have reported on the response to fertilizer of oaks (but not bear oak) (Det- DISCUSSION wiler 1943:915, Farmer et al. 1970:132, Ward and Bowersox 1970:116, Auchmoody Age and fertilizer interacted in their ef- 1972:2-4) and other hardwoods and coni- fects on acorn productivity at all 3 stages of development-pistillate flowers, fers (Hostetter 1943:88, Shoulders 1968: immature acorns, and mature acorns. Ferti- 194-95). Therefore, it is not surprising to lizer exerted its greatest effect on bear oak find increased acorn yield in fertilizer stands that were at least 9 years old but treated bear oak. The cause of the age x failed to effect 5-year-old stands (Figs. 1, fertilizer interaction cannot be determined 2, 4, 5, 7, 8). Productivity in unfertilizedfrom these studies. stands declined between 5 and 13 years of Stand density, measured as clumps-per- age. Although fertilizer did not influence hectare, had relatively little influence on the mature acorn crop during the fall fol- the amount of acorn production in bear lowing the first application, there was a oak. Interactions between stand density at positive response the following fall and, the levels studied and both age and ferti- J. Wildl. Manage. 41(4):1977 This content downloaded from 73.84.198.143 on Wed, 01 Nov 2023 18:39:35 +00:00 All use subject to https://about.jstor.org/terms AGE, DENSITY, AND FERTILIZER EFFECTS ON BEAR OAK" Wolgast and Stout 691 lizer application were not significant in LITTLE, E. L. 1953. Check list of native and naturalized trees of the United States. U.S. terms of acorn productivity. Dept. Agric. Handb. 41. 472pp. LITTLE, S., G. R. MOORHEAD, AND H. A. SOMES. CONCLUSIONS 1958. Forestry and deer in the pine region of New Jersey, N.E. For. Exp. Stn. paper 109. To maximize the yield of acorns by bear 33pp. oak, the land manager should develop a MARTIN, A. C., H. S. Zihi, AND A. L. NELSON. systematic plan of cutting back some old 1951. American wildlife and plants. McGraw- stands, while fertilizing other uncut olderHill Book Co., Inc., New York. 500pp. McDOWELL, R. L. (ED.) 1975. New Jersey's stands. The objective should be to maintainwhite-tailed deer. Deer Report No. 2. New a high proportion of stands 5 to 7 years old Jersey Division of Fish, Game and Shellfish- eries. 23pp. or less. This would significantly increase SHOULDERS, E. 1968. Fertilization increases food production for many species of wild- longleaf and slash pine flower and cone crops life. It would be especially valuable to in Louisiana. J. For. 66(3):193-197. white-tailed deer on New Jersey's outer SOCIETY OF AMERICAN FORESTERS. 1967. For- est cover types of North America. Society of coastal plain and in other areas where high American Foresters, Washington, D.C. quality winter food is in short supply. SOKAL, R. R., AND F. J. ROHLF. 1969. Biometry. W. H. Freeman and Co., San Francisco. 776pp. LITERATURE CITED VAN DERSAL, W. R. 1938. Native woody plants of the United States: their erosion-control and AUCHMOODY, L. R. 1972. Effects of fertilizer- nutrient interactions on red oak seedling wildlife values. U.S. Dept. Agric. Misc. Publ. growth. U.S. Dept. Agric. For. Serv. Res. 303. 362pp. Paper NE-239. 5pp. WARD, W. W., AND T. W. BOWERSOX. 1970. Up- DETWILER, S. B. 1943. Better acorns from a land oak response to fertilization with nitro- heavily fertilized white oak tree. J. For. gen, phosphorus, and calcium. For. Sci. 16(1): 113-120. 41( 12):915-916. EDMINSTER, F. C. 1947. The ruffed grouse. The WIDMER, K. 1964. The geology and geography Macmillan Co., New York. 385pp. of New Jersey. D. Van Nostrand Co., Inc., FARMER, R. E., JR., C. W. BENGTSON, AND J. W. Princeton, N.J. 193pp. CURLIN. 1970. Response of pine and mixed WOLGAST, L. J. 1972. Mast production in scrub hardwood stands in the Tennessee Valley to oak (Quercus ilicifolia) on the coastal plain nitrogen and phosphorus fertilization. For. in New Jersey. Ph.D. Thesis. Rutgers Univ., Sci. 16(2):130-136. New Brunswick, N.J. 137pp. HOSTETTER, L. K. 1943. The use of fertilizer in a walnut orchard. Northern Nut Growers Received 17 February 1976. Assoc. 34th Annu. Rep. 126pp. Accepted 13 July 1977. J. Wildl. Manage. 41 (4):1977 This content downloaded from 73.84.198.143 on Wed, 01 Nov 2023 18:39:35 +00:00 All use subject to https://about.jstor.org/terms