B -1 183 November 1977 Macartney Rose - Infested Coastal Prairie METRIC UNITS - ENGLISH EQUi Metric E Unit E Centimeter 0394i Hectare 2.47 - Kilogram 2.205 w Kilogram per hectare 0.893 ~ o1 Kilometer » 0.62 s H Kilometer per hour 0.62 mi Liter 0.264 Meter 3.28 Square meter 10.758 "s _‘ (Degrees centigrade X 9/5) Degree + 32 Mention of a trademark name or a proprietary p u ~ » tute a guarantee or warranty of the product by the Experiment Station and does not imply its approval other products that also may be suitable. t , '!“T ‘ re.- CONTENTS METRIC UNITS -~ 3 ENGLISH EQUIVALENTS . . . . . . . . . . . . . . . . 2 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 MATERIALS AND METHODS . . . . . . . . . . . . . . . . . 6 Description of the Study Area , . . . . . . . . . . . . . . 6 Experimental Burns . . . . . . . . . . . . . . . . . . . . . . . . 7 RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7 Relationship of Fire Characteristics t0 ~ Fuel Load and Environmental Conditions During Burning . . . ; . . . . . . . . . . . . . . . . . . . . . 7 Response of Macartney Rose to Burning . . . . . . 9t Response of Herbaceous Vegetation to Burning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Forage Utilization Following Burning . . . . . . 12 The Fire Plan . . .1 . . . . . . . . . . . . . . . . . . . . . .. 12 DISCUSSION AND CONCLUSIONS . . . . . . . . . .. 14 ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . 14 LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . .. 15 SUMMARY J Infestations of Macartney rose, a pro than ZOQOMbec-fams" OfTGXEIS Coastal ' a; reduce range forage production, restrict li ment, and hinder effective management of Since Macartney rose is apparently a volatil studied as a potential improvement practice » infested with this troublesome plant. Under a narrow range of wind =»__l kilometers per hour, Macartney rose immediately following burning was directly V’ amount of dead herbaceous standing fuel i; and fuel moisture content. Season of burni y to determine the fine fuel load and the pro fuel as dead standing crop. _ Although the Macartney rose canopiy pletely removed, the percentage of plants was negligible. After top removal by burni _: rose canopy replacement occurred fro V} originating from the plant bases. Elongatio canes averaged 3 to 4 centimeters per mon of season of burning. Macartney rose can ' ment, based on canopy cover, averaged 1O if, per month following burning. Although can year after burning usually equalled the p Q plant growth form was altered. Macartney tended to assume a low spreading growth h burning as contrasted to the more upright unburned plants. This change in growth f0 of the brush growth below the tops of the 9 - if access to forage by livestock in burned pas Burning in winter effectively reduced rose canopy for short-term gains in brush‘ allowed the native range grasses to take ad entire spring growing period. This result -- j herbage yields by fall than on areas burned i_ summer, or fall. Within 120 days followiutg February, green herbaceous standing crop; mately equal to that of unburned areas. standing crop of herbaceous plants followi the winter was significantly higher than that , areas. Removal of the dense Macartney rose l. heavy mulch layers encouraged grazing use during the spring and summer following wint native of China and Formosa, Macartney rose (acteata Wendl.) was introduced into the United the early l800’s as hedge rows. It escaped culti- Texas, Oklahoma, Arkansas, and Louisiana. Also "Cherokee” and “rose hedge,” Macartney rose me a severe management problem in southeast specially on the Coastal Prairie and Marshes, a area of highly productive rangeland and farrn- i»: rtney rose also occupies extensive areas of the ds, Post Oak (Quercus stellata Wangenh.) , and Blackland Prairies of Texas (1). 0 dy perennial with trailing thorny canes (Figure l ey rose produces white flowers 5 to 7 cen- (in diameter (3). The plant evidently is of minor gialue although young leaves, canes, and floral occasionally browsed by cattle (5). Seed germi- y after passing through the digestive tracts of f’! and the manure affords an excellent environ- ifeseedling establishment. The species may also xually by canes which root at nodes after being Onto moist soil. it is a vigorous evergreen and the Coastal étypified by a growing season in excess of 300 rtney rose may cover extensive areas in a short se clumps may exceed 3. 5 meters in height and tin diameter (Figure l). On heavily infested rtney rose canopy cover many exceed 75 per- Fand forage production is virtually eliminated i: canopies. Since livestock are restricted to ‘marily those areas between Macartney rose ‘ng capacities on heavily infested range may ~ to one animal unit per 8 hectares compared condition range of equal potential which may r - animal unit per 2 to 3 hectares. gle control practice has been highly effective if improvement of Macartney rose-infested etric to English units, see table inside front cover. , research technician, The Texas Agricultural Experiment i}. illicothe-Vernon; and professor, The Texas Agricultural fstation (Department of Range Science). Burning for Improvement of Macartney Rose-Infested Coastal Prairie R. A. Gordon and C. J. Scifres* rangeland. The canopies are only temporarily reduced by mechanical practices such as raking and stacking, shred- ding, or roller chopping Young Macartney rose plants and seedlings often can be effectively controlled with a single application of 2,4-D applied at 1 pound per acre. However, mature plants may require three or more consecutive applications of 2,4-D for effective control. Macartney rose regrowth is more difficult to control than is the undisturbed growth form After application of herbicides, standing dead Macartney rose canes can re- sult in a greater management problem relative to care of livestock than did the original growth (12). Also, multiple herbicide applications are costly and greatly reduce the production of forbs in the grassland community. Many broadleaved species are valuable for grazing, especially by wildlife, and for upland game bird habitat (13). The steady increase in cost of chemical and mechani- cal range improvement practices necessitated the inves- tigation of effective, less costly practices such as burning for improvement of Macartney rose-infested rangeland. Fire is a natural factor, and probably no range site has developed without its influence (4, 16). Prescribed burn- ing, in contrast to wildfires, is the systematic firing of land when favorable weather and vegetation characteristics are expected to maximize benefits (16). Seed of many plants germinate readily following range burning, and seedling establishment is facilitated by contact with min- eral soil rather than with superficial layers of organic debris. Mulch, that layer of dead plant material on the soil surface, contains nutrients that are largely unavailable for growth until released slowly and, usually incompletely, by decay. By contrast, burning releases nutrients rapidly and more completely than natural decomposition, result- ing in a short-term fertilizing effect (18). During moist seasons, soil temperatures increase following burning, and nitrification is stimulated (19). Prescribed burning may be effective for controlling parasites of large mammals on Coastal Prairie rangeland (8). Insects and fungi that are faeultative parasites often must live in plant debris until conditions become favor- able for attacking living hosts (4). Fire has been used as a management tool in the southeastern United States t0 reduce brush cover and maintain forbs and grasses in a vigorous growing condi- tion, increasing food availability for bobwhite quail (C01- inus virginianus L.) and wild turkey (Meleagris gallopavo L.) (10, 14, 15). Scifres (12) proposed a system incorporating burning in winter with use of herbicides for improving Macartney rose-infested rangeland. Regardless of application rate, aerial sprays of 2,4,5-T ( (ZA,5-trichlorophenoxy)acetic acid) + picloram (4-amino-3,5,6-trichloropicolinic acid) (1:1) applied in the fall were more effective than 2,4,5-T, ZA-D ((2,4-dichlorophenoxy)acetic acid) or dicamba (3,6-dichloro-o-anisic acid), applied alone or in combina- tion, for reducing density of live Macartney rose plants. Prescribed burning following the most effective chemical treatments 1.12 to 1.68 kilograms per hectare of 2,4,5-T + picloram) increased topgrowth control of Macartney rose compared to spraying alone and provided accept- able control levels for at least 3 years. However, there was no available research concerning potential variation in response of Macartney rose to season of burning. Pre- vious research emphasized the use of herbicides fol- lowed by fire, and winter was arbitrarily chosen for in- stallation of burns (12). Therefore, information was needed relative to season of prescribed burning for maximum initial canopy reduction of Macartney rose which had not been sprayed, maintenance of topgrowth control, and optimum production of range forage. In 1975, research was initiated to study burning alone as a potential improvement method for Macartney rose-infested rangeland. Specific objectives were to (a) evaluate the extent and rate of regrowth of Macartney rose following burning at various seasons as related to selected environmental conditions, fuel characteristics, and stage of plant growth, (b) determine the duration of Macartney rose topgrowth suppression following bum- ing, (c) evaluate range forage production and utilization 6 Figure 1. Undisturbed Macartney; tations near Bloomington in " Prairie of Texas. following burning, and (d) develop an effective i. for prescribed burning on the Coastal Prairie. MATERIALS AND METHODS Description of the Study Area The research site was in northwestern County approximately 5 kilometers sout, Bloomington, Texas. The area is level to gently‘ p _ ing, primarily a Blackland range site, and no m0 meters above sea level. Climax vegetation is prairie supporting big bluestem (randropogonf Vitman var. gerardii), little bluestem (Sch scoparium (Michx.) Nash var. frequens (F. T.‘ switchgrass, (Panicum virgatum L.), and yello grass (Sorghastirum nutans (L.) Nash.) as the i_ decreasers. Increasers include longtom lividum Trin.), knotroot bristlegrass (Setaria (Lam.) Beauv.), brownseed paspalum (Pdf plicatulum Michx), and several low-growing s; Panicum and Dicanthelium. Rattail s if, (Sporobolus indicus (L.) R.Br.), broomsedge o, (Andropogon virginicus L.), snow-on-the‘ (Euphorbia bicolor Engelm. and Gray), spiny as spinosus- Benth.), and bushy sea-oxeye (Barrio cens DC.) are herbaceous invaders. Berm (C ynodon dactylon (L.) Pers.) and dallisgrass dilatatum Poir.), introduced grasses common on i tame pastures, have encroached upon portio study area. The primary soils, Lake Charles and Victo are montmorillonitic, basic in reaction (pH _. than 1O percent sand, more than 6O percent clay", p than 1 percent organic matter in the surface 15 M: ers (11). The soils are weakly developed, ve permeable, drouthy in summer, and often satura late fall to early spring. Average annual rainfall is i 3f ters, and the annual frost-free period is 300 days a ‘_ heavy infestations of Macartney rose on most of were treated with 2.24 kilograms per hectare of 1966 and with 1.12 kilograms per hectare of the annually from 1967 through 1971. Several un- l strips had been maintained to provide cover for g ant white-tailed deer (Odocoileus virginianus lation. The pasture in which the experimental - located is usually grazed by cattle from late = late fall. Experimental Burns _‘ . -. were installed as headfires at 2- to 3-month beginning in February 1975. The experiment 3 ed as a randomized complete block with four Ans. Plots were 61 by 91.5 meters (approximately l - es) and separated by disced buffer strips 9 'de. ' I to burning, two 30.5-meter permanent trans- t 6.5 meters apart, were established diagonally plot. Foliar cover interception by live y rose was recorded prior to burning and period- the fires Interceptions spaced less centimeters apart along the lines were recorded nous canopy cover. Average cane length of rose regrowth (from ground line with cane r ollowing burning was measured for each inter- permanent lines established for monitoring rose canopy cover replacement were also 'on of herbaceous plant basal cover (1). Basal m 1O permanent sampling areas were taken i rs apart along each line at 2-month intervals ieach burn. (‘ately prior to each burn, ten 0.25-meter- A‘ pling areas, equidistantly spaced diagonally plot at 7-meter intervals, were harvested to a feter stubble height. Standing herbaceous fuel separated into green and dead. Mulch was divided into fine (é 0.3 centimeter diameter) ;;;(> 0.3 centimeter diameter) classes. All fuel sealed in aluminum cans, air-dried at 65 ‘ntigrade for 48 hours and weighed. Air-dry ‘ntent of standing herbaceous growth and i. ~ oven-dry (105 degrees centigrade for 48 ilisture content of soil were determined on Isles from each plot. Soil samples were recov- .19 to 2.5, 2.5 to 15, and 15 to 30 centimeters ,ironmental conditions, including relative temperature at 2 meters above ground gmperature at 2.54 centimeters deep, and pity and direction at 2 meters above ground imonitored during each burn. A (lithe plots were backfired on the leeward side(s) meters, the headfire was ignited on the wind- Duration of the burn, as recorded for this when the headfire was ignited and ended adfire and backfire met. placement of inclined 10-point frames for ’ Asbestos cards supporting fire sensitive Tempilz pel- lets behind mica sheets were used to estimate maximum temperature attained during the burns. Three tempera- ture monitoring stations, each consisting of mica sheets with pellets placed at O, 30, and 45 centimeters above ground level, were placed in each plot. Immediately following the burns, percentage of the plot area burned and percentage Macartney rose canopy reduction were visually estimated. Five portable exclosures were established in each plot to allow periodic evaluation of range forage produc- tion and utilization following the burns (13). The exclo- sures, constructed from 10-gauge welded wire with 10- by 10-centimeter openings, were approximately 1.5 meters tall and 1 meter in diameter. The term “forage utilization” will be used herein to relate net forage loss —— the combination of influences such as weathering, trampling, consumption by Wild animals and insects as well as forage consumption by livestock. The exclosures were placed on a diagonal line perpendicular to the permanent lines es- tablished for evaluation of Macartney rose canopyre- placement. Herbaceous vegetation in O.25-meter square sampling areas was harvested to a 2.5-centimeter stub- ble from the center of leach exclosure. Approximately 4 meters from each exclosure, a O.25-meter-square area was harvested from the grazed vegetation. Green her- baceous topgrowth, separated into live grasses, forbs, and woody plants, standing dead herbaceous material, and coarse and fine mulch, was air-dried and weighed. Dif- ferences in herbaceous standing crop between protected and grazed samples were used to estimate forage utiliza- tion for that grazing period. Harvests from within each exclosure were used to estimate production. After har- vesting, the exclosures were moved a predetermined distance along the permanent line to begin another graz- ing period. Forb response in burned areas previously occupied by the Macartney rose canopy was assessed in May and September 1975 and in April 1976. Four lines were estab- lished from the base of four, randomly selected Macartney rose plants, outward in the four cardinal direc- tions until the perimeter of the original Macartney rose canopy was intercepted. Forb height and density by species were recorded in contiguous sampling areas, 0.6 by 0.6 meter, along each line. RESULTS Relationship of Fire Characteristics to Fuel Load and-Environmental Conditions During Burning Herbaceous fuel for burns in the winter consisted almost totally of dead standing material since the warm season grasses, which afforded the bulk of fine fuel, were dormant (Table 1). Spring growth increased the total standing herbaceous fuel in April and Iune, compared to the fine fuel load in the winter, and decreased the propor- tion of total fine fuel afforded by standing dead material. 2Manufactured by Tempil, Div. of Big Three Industries, So. Plainfield, N. 1. 7 TABLE 1. AIR-DRY FUEL LOAD (KILOGRAMS PER HECTARE), EXCLUDING GREEN MACARTNEY ROSE, IMMEDIA TO BURNING COASTAL PRAIRIE AT VARIOUS DATES NEAR BLOOMINGTON, TEXAS, IN 1975 ~ Fuel components 1‘ i’ a i é ‘ a.‘ Fine fuel Burning Standin date g Coarse (1976-76) Green Dead Mulch s Total mulcha Feb. 26 Tb 3,460 3,723 7,163 16 April 16 3,064 2,096 3,620 6,760 " 6 June 3 3,944 2,243 4,396 10,663 30 Oct. 16 2,624 1,366 2,976 7,166 10 Jan. 10 Tb 4,160 2,293 6,443 21 aFine mulch was less than or equal to 0.3 centimeter in diameter; coarse mulch was greater than 0.3 centimeter in diameter. Trace amounts of green matter were noted but could not be effectively separated. There was also a reduction in the amount of dead standing fine fuel available in the fall compared to that in the winter, presumably due to drying, collapse, and dete- rioration of the standing herbaceous material. The amount of fine mulch tended to be greater in the summer than during other seasons of burning. Relatively low amounts of coarse mulch, consisting primarily of broken Macartney rose canes from previous herbicide applica- tions in the 1960’s, were present (Table 1). The estimated contribution of coarse mulch is biased somewhat since the area directly under Macartney rose plants could not be sampled. Burns installed in the winter (February 1975 and January 1976) were conducted under bright skies with an average wind velocity of 13 kilometers per hour and occa- 1 sional gusts of 19 kilometers per hour (Table 2). Burns installed in January were conducted with wind from the southeast and 38 percent fuel moisture content as con- trasted to the February burns with winds from the north- west and fuel moisture content of 15 percent. Flame heights exceeded 8 meters, and rate of movement of the fire front exceeded 14.5 meters per minute (Table 3). Effective area burned (that blackened by fire) was 8O to 95 percent. Average maximum temperature of the flame front reached 337 degrees centigrade at ground line and 316 degrees centigrade at 46 centimeters above ground line (Table 2). During the same time of year, under the same monitoring system and at the same location in another study, maximum temperatures of 566 degrees centigrade were achieved at 15 centimeters above ground line The reasons for the consistently lower tempera- tures in the present study are not clear. TABLE 2. ENVIRONMENTAL CONDITIONS DURING BURNING OF MACARTNEY ROSE-INFESTED COASTAL PRAlFlii IOUS DATES NEAR BLOOMINGTON, TEXAS Burns in the spring (April) were vi wind speeds averaging 24 kilometers per hop‘, but rate of fire front movement was only 8.7;, minute (Table 3). Although air temperature centigrade higher during burns in April burns in February, relative humidity was cent, respectively. Also, over halfof the fine afforded by green herbage (Table 1). These, sulted in fuel moisture percentage in April n5,_i_ twice that in fuel available for burning in Feb if 2). Rate of fire front movement in the sum“ with 35 percent fuel moisture and lower wind .. kilometers per hour) than the burns in April, a meters per minute (Table 3). Higher fiiel 1 tent reflected the increased contribution of . baceous top growth to total fine fuel during, June (Tables 1 and 2). The slowest burn, 00nd l‘ fall (October) (Table 3), was installed kilometer-per-hour wind speed, 48-perce moisture content, and 66-percent relative h ble 1). About one-third of the fine fuel load f? by green material. Maximum flame height a ing burning in October was approximately 4 fire was slow and relighting was required en“, four plots. However, once adequately ignit age maximum temperatures were equal to or F_ in burns installed in the winter (Table 2). l Duration of burn (inversely related to ‘ front movement) was correlated more closely? moisture content and amount of dead standii,_ oust material (fine fuel) than with air temperatu -{ humidity, and moisture content of the mulch. ‘é - r ' "are: . Fuel - Burning Wmd Temp (C) Relative moisture firftzgmrgz:a'rlu*f date Speed Direction Air Soil humidity content ' (1975-76) (kph) (%) (%l 0 cm 3O cm "i6. Feb. 28 13 N 22 19 58 15 337 323 April 15 24 SE 28 20 7O 29 267 309 June 3 15 S 30 2O 65 35 8 a Oct. 15 16 SE 2O 23 66 48 357 329 Jan. 1O 13 SE 19 18 57 38 260 288 aData not taken. 8 A E 3. ESTIMATED MACARTNEY ROSE CANOPY REDUC- I%l IMMEDIATELY FOLLOWING BURNING AND RATE E FIRE FRONT MOVEMENT NEAR BLOOMINGTON, ning Canopy Rate of reduction burn ,___5-76) (%) (m/min) Jo. 49a 147' ff: t as 8:7 '~ = 78 7.4 78 4.0 96 14.5 reduction approximately 2 weeks following burning was 9O f 1. - ‘Iwas negatively correlated with the amount of dead g fine fuel (r = -0.66). Percent moisture of fuel sitively correlated with duration of burning (r = iThe lack of correlation of rate of fire front move- { wind speed was expected since a relatively ‘range of wind speeds was used (Table 2). d on these data, burning in the winter when the was composed totally of dormant herbaceous of low moisture content resulted in the most rapid jtes. Burning in the spring or summer with a high Fifi of green fine fuel resulted in slower, but not ly hotter, fires. In the Coastal zone, burning in other seasons, a response to the low proportion of afforded by dead standing fine material (only 9- Iograms per hectare in this study) (Table 1), and a Jjfuel moisture content (Table 2). j» nse of Macartney Rose to Burning ney rose canopy reduction (Table 3) was not correlated with environmental conditions at burning, probably as a result of (a) an inability {y assess small differences in burndown and (b) fvely high effectiveness of most burns in reducing rose topgrowth. The lowest initial canopy re- ioccurred following the February burn. However, '1 p. h from the burn resulted in removal of 9O got more of the Macartney rose canopy within 2 er the fires, regardless of date of burning. wth of Macartney rose was initiated within 2 ;- dless of burn date. Canopy reestablishment 1» the original cover occurred at 6 to 8 percent per ‘gable 4). Average cane elongation was 3.9 cen- C,» A r month with little apparent variation attribut- ‘(apparently will result in much slower fires than ' able to time of burning (Table 5). Characteristically, Macartney rose regrowth developed vertically to approx- imately 15 to 20 centimeters before the canes bent and growth continued laterally. lWhere debris from burned Macartney rose was still intact, regrowth trellised over the dead canes, resulting in greater canopy heights than on areas with complete burndown. Response of Herbaceous Vegetation to Burning Although burning did not kill the Macartney rose plants, top removal by the fires greatly reduced the influ- ence of the woody plant on the herbaceous species. The effect of the fires on the Macartney rose, removal of the “rough” (dead standing herbaceous growth), and reduc- tion in the heavy mulch cover which can retard de- velopment of herbaceous plants (10) apparently pro- moted rapid growth of herbaceous species. New growth was quickly initiated following the winter burn and in- creased rapidly during the first 2 weeks of March 1975. Although production of green herbaceous growth in April was less on areas burned in February than on un- burned plots, production on burned areas equalled that of unburned areas by July 1 (Table 6). Cumulative pre- cipitation by April was about 59 percent of normal for that period but was above average by July. However, soil moisture content was 37 percent in the surface 2.5 cen- timeters at the same time of the winter burn, apparently adequate for initiation of new spring growth. Burning in April removed the early spring produc- tion so that standing herbaceous crop in Iuly was signifi- cantly less than on unburned plots or on those burned in February. Conditions were relatively dry preceding the burn in April, and soil moisture content in the surface 2.5 centimeters was only 15 percent. However, rainfall was higher than normal following the burn and until late summer. These data suggest that the dry conditions pre- ceding the spring burn and relatively low soil moisture at TABLE 5. MEAN PLANT HEIGHT (CM), CANE LENGTH ICMI, AND AVERAGE CANE ELONGATION RATE OF MACARTNEY ROSE BY APRIL 1976 FOLLOWING BURNING AT VARIOUS DATES NEAR BLOOMINGTON, TEXAS Burning Plant Cane Cane date height length elongation rate (1975-76) (cm) (cm) (cm/mo) Feb. 29 55 4.2 April 19 41 3.4 June 17 40 3.9 Oct. 13 19 3.2 Jan. 10 13 . 4.6 NMACARTNEY ROSE CANOPY REPLACEMENT AS A PERCENTAGE OF Tl-IE ORIGINAL CANOPY COVER BY VARIOUS OMINGTON, TEXAS ILLOWING BURNING OF COASTAL PRAIRIE NEAR BLO Evaluation date . 1975 1976 Apfii May Juw sax. Now Mamh Apm 4 45 57 62 76 99 97 - 7 23 39 as 74 71 - - 5 41 71 70 67 _ -_ - - 1 21 40 - - - - - 14 25 TABLE 6. AIR-DRY YIELDS (KG/HA) OF TOTAL HERBACEOUS STANDING CROP FOLLOWING BURNING OF MACAR lNFESTED COASTAL PRAIRIE NEAR BLOOMINGTON, TEXASa B“'"'"9 Harvest date (1975-76) date (1975-76) April 20 July 1 Aug. 17 Nov. 21 None 2147 b 2766f 4145 mn 1556 t Feb. 618 a 2856f 4830 n 1928 u April — 1833 e 3400 m 14,03 t June — 549 d 1974 l 10.38 s Oct. — — — 160 r Jan. —— — —- — Cumulative ppt. (cm) 10.36 46.96 62.42 79.74 Departure from normal (cm) —7.30 +10.85 +11.23 —1.76 aMeans within each column followed by the same letter do not differ significantly (P 2 0.5), using Duncan's New Multiple Range Ti; bBased on rainfall records from the U. S. Weather Bureau at Victoria, Texas. ' the time for burning may have restricted the rate of response of the herbaceous vegetation to fire. Removal of spring production by burning in June was also evidenced by significantly reduced herbaceous standing crop on July 1, 1975, compared to other treat- ments. By late summer (August 17), plots burned in February yielded 4,830 kilograms per hectare of standing crop, the highest production for that evaluation date and for the study. However, production of herbaceous top- growth following burning in June was reduced for the entire summer and into the fall compared to earlier burns or unburned areas. Warm season grasses, the major con- tributors to botanical composition of the vegetation, were entering dormancy by time of evaluation in November. Cumulative rainfall by the fall evaluation was near normal. Plots burned in February supported signifi- cantly more standing crop in November than did other treatments. However, total green herbaceous production decreased in November compared to that of evaluations in August, regardless of burn date. This is a natural occur- rence due to weathering during the fall. By May 1976, almost a year and a half following the first winter burn, standing crop was not significantly dif- ferent among plots regardless of burning treatment (Table 6). Although, standing crop tended to be lower in May 1976, where burns were installed the previous October and January, the reduction was not significant. Forb production on Coastal Prairie is typically highly variable and relatively low compared to grass production. Forb production increased dramatically following burn- ing in late February 1975 compared to unburned Coastal Prairie (Table 7). Annual forbs such as Texas croton (Cro- ton texensis Muell. Arg.), snow-on-the-prairie, pink rose- gentian (Sabatia campestric Nutt.), and dayflower (Commelina anomala (Torr.) Woodson) were espe- cially prominent following the February burning. Stand- ing crop of forbs in rnid-summer (July 1975) was approxi- mately three times greater on areas burned in February than on those burned in April, June, or on unburned areas. F orb release, apparently a short-term effect of burning, was not apparent by late summer (August 1975). F orb production decreased dramatically during the hot . summer months, regardless of time of burn. F orb produc- 1O J previously covered by the dense MacartneY r0 tion in May 1976 was highly variable althoup areas tended to support higher forb producti 1 unburned areas. As previously mentioned, herbaceous essentially eliminated under the heavy Mal canopies. Over half of the land surface area on, site may be covered by the woody plant can, Removal of the Macartney rose topgrowth opened these areas for establishment of her,“ age species. Immediately following burnin‘ layer of white ash was deposited on the ci Following burning in February, vegetation these areas followed a typical pattern of se wf cession, initially supporting numerous Texas u; knotroot bristlegrass seedlings. As the herbal. tation recovered from burning, location of Macartney rose plants was evidenced by ci terns composed almost solely of robust Texas height and density during the initial months‘, the February burn varied directly with the a gree of potential competition of other specie§§ stance, at 0.6 meter from the center of theie. Macartney rose plants, Texas croton averaged per meter square with an average height of timeters (Figure 2). This zone supporte Macartney rose regrowth, typically erect with" TABLE 7. AIR-DRY YIELDS (KG/HA) OF FORB CROP FOLLOWING BURNING OF MACARTNEY. FESTED COASTAL PRAIRIE NEAR BLOOMINGTON, Harvest date Burning date ‘Q75 (1975-76) April 20 July 1 Aug. 17 Nov. 21 None 0 a 56 e 13 l 0 r Feb. 56 b 163 f 26 l 52s April — 54e 18 l Or June — 57 e 28 l 19 rs i Oct. — —- — 1 r i Jan. — — -— — aMeans within each column followed by the same letter fer significantly (P 2 0.05), using Duncan's New Mu l Test. “ §0.5-meter lateral growth originating from base of ned plant, within 2 weeks following burning. _l§0.6 to 2.5 meters from the center of the original ‘ n ey rose plant, Texas croton density exceeded 11 i, per meter square with an average height of over a timeters. At the time of evaluation in May, ey rose regrowth had not extended into the 2.5-meter zone. At 2.5 to 3.1 meters from the of the burned Macartney rose canopy, Texas cro- - f; t drastically decreased, 45.7 compared to 95.3 jters; and the density decreased to 6.4 plants per meter. Both density and height of the Texas cro- . ased gradually to a distance of 4.9 to 5.5 meters center of the original Macartney rose canopy. s croton occurred within the stands of perennial beyond the original Macartney rose canopy er. With time following the burn, the circular .14.». me reoccupied with Macartney rose and with grasses such as brownseed paspalum, silver ff , and little bluestem. Observations in fall 1975 lng 1976 showed no difference in forb presence in as compared to presence in the interspaces be- .1 original Macartney rose plants. percentage of bare ground was dramatically in- Qby burning, primarily by removal of the mulch wever, by mid-summer there were no differ- percentage of bare ground between plots _,in February and April 1975. As would be ex- greatest amount of bare ground occurred on f_ recent burn (June). Unburned plots, charac- mulch accumulation, maintained a high per- ground cover regardless of evaluation date. ‘T1975, percentage of bare ground was reduced on *1 areas except those installed in October. The *5 na-an ogngify l l I 1.2—1.l 1.0-2.5 2.5-3.1 Y!‘ l ', 0.4-1.2, a.1-a.1 3.1-4.3 44-4.: 4.0-5.5 Disloncolmifrom Cantor O1 Macartney Rose Plant I-I-Avgl-loight _.I 5.5- $1 reductions were largely attributed to mulch deposits during the winter and the spring growth response which increased the density of live grass culms. Reestablish- ment of herbaceous vegetation following the October burns was slow during the winter months; this increased the chances of mulch being scattered by winds. Throughout the study period, mulch cover was typically highest in unburned plots, and occasionally accumula- tions exceeded 2.5 centimeters deep. As expected, green grass basal cover fluctuated with season as well as with time after burning. By November, highest basal cover of green grass occurred where burns had been installed the previous February or April; this probably reflected the original higher density of com- mon bermudagrass and longtom. Ground cover (data not shown) of forbs on burned areas in November generally reflected overall trends in forb production (Table 7) ex- cept on those areas burned in October. Although forb production on areas burned in October was lower than that on other areas, forbs afforded more of the ground cover. This difference occurred because forbs typical of the October burn, particularly yellow woodsorrel (Oxalis dillenii ]acq.), were mat-like in growth form, whereas those following burns in other season were erect in growth form. Mulch cover is important in buffering the soil sur- face against temperature extremes and in reducing rate of moisture loss (17). However, excessive mulch cover, exemplified by unburned areas in this study, can restrict growth and development of new seedlings and delay soil warming in spring. Mulch accumulations by May follow- ing burning in February averaged 1,529 kilograms per hectare. The highest accumulations following other burn Figure 2. Mean height and density of Texas croton on burned areas previously covered by, Macartney rose canopies on April 20, 1975, near Bloomington, Texas. The areas were burned in February. uogoag $01101 p ¢zm9gbluuo|dy Aggsuoq 5.1-6.1 11 dates averaged 638 kilograms per hectare after the fires in April (Table 8). At this same time, the untreated area supported over 2,800 kilograms per hectare of mulch. Removal of dead standing herbaceous material, of little value to grazing animals, to allow replacement with green forage growth is considered an attribute of burn- ing. Dead standing herbaceous growth was effectively reduced by all burns, and the reduction was still appar- ent in May, 17 months following the earliest burns (Ta- ble 9). Replacement of the dead standing topgrowth is important to restore. the mulch cover to adequate levels following burning. Forage Utilization Following Burning On August 17, 1975, utilization of herbaceous top- growth was greatest following February burns (Table 10). Livestock were allowed to use the pasture contain- ing the burned areas from Iune 5 to August 31, 1975, and from November 11, 1975, to March 31, 1976. Thus, the burned areas were subjected to differential deferment periods following burning, ranging from about 4 months with the winter burn to essentially no deferment for the summer burn. Forage utilization on plots burned in February represented approximately 45 percent of the standing crop in contrast to 23 percent utilization on adjacent unburned areas. TABLE 8. AIR-DRY YIELDS (KG/HA) OF MULCH AT VARIOUS DATES FOLLOWING BURNS ON MACARTNEY ROSE-INFEST- ED COASTAL PRAIRIE NEAR BLOOMINGTON, TEXASa Harvest date B“’"'"9 1975 1976 date (1975-76) April July Aug. Nov. May None 3276 b 3924 g 3979 rn 3554 u 2806 z Feb. 475 a 301 e 290 I 1332 t 1529 y April — 910 e 257 I 542 rs 638 x June - 1670 f 108 I 264 r 442 x Oct. - — —- 1 107 st 365 x Jan. — — — -— 503 x aMeans within each column followed by the same letter do not dif- fer significantly (P > 0.05), using Duncan's New Multiple Range Test. TABLE 9. AIR-DRY YIELDS (KG/HA) OF DEAD STANDING HERBACEOUS MATERIAL FOLLOWING BURNS ON MACART- NEY ROSE-INFESTED COASTAL PRAIRIE NEAR BLOOMING- TON,TEXASa Harvest date Burning 1975 1976 date (1975-76! April July Aug. Nov. May None 3560 a 1366 f 993 m 1422 t 1675 2 Feb. 71 b 25 e 34 I 756 s 760 y April — 0 e 0 I 267 r 487 xy June — 41 e O I 88 r 166 wx Oct, - — — 271 r 33 w Jan. - — — — 0 W TABLE 10. DIFFERENCES IN TOTAL HERBACE GROWTH YIELDS (KG/HA) FROM PROTECTED ANQ“ AREAs DURING GRAZING PERIODS FOLLOWING o1= COASTAL PRAIRIE NEAR BLOOMINGTON, TEX s, f: . 1a Burning Harvest date i‘ date g (1975-76) Aug. 17, 1975 May 15,Q None 92s a 1562“ Feb. 2184 6 1755 April 1616 ab 16091 June 1165 ab 21255; Oct. _ 879». Jan. — aMeans within each column followed by the same letter fer significantly (P > 0.05), using Duncan's New Mul ' Test. l. n, ., , \ Forage utilized by August following burns. totaled 1,616 kilograms per hectare, and 1,165 per hectare were removed from the plots o‘? June. Although utilization of forage by these 1;; not significantly greater from burned than ‘ burned plots, total forage production was lower of the short period from burning until evaluatil sequently, percentage total utilization by burning in Iune represented approximately percent, respectively, of the forage utilized . burned plots and those burned in the previ’, ruary, April, or June. Forage utilized by May . ing in October or January, representing livest u only one growing season, was significantly l6 from other treatments. However, percentagf used was relatively high since utilization repre and 65 percent of the forage produced, respe Although there was a trend for increas forbs on the burned areas, there were no si differences in forb utilization regardless of treat the August 1975 and May 1976 evaluation dates. gust 1975, only about 9 kilograms per hectare. were removed from unburned areas, whereas f0 zation ranged from 10 to 22 kilograms per hecta burned areas. No forb use was detected on u areas in May 1976, whereas utilization ranged fr 72 kilograms per hectare on burned areas. I The Fire Plan Prescribed burning is a legitimate range i ment practice which requires the same care in p tion and execution as mechanical or chemical i ment practices. Benefits to the rancher from canopy reduction, such as increased forage prodi depend on the effectiveness of burning tr . w - r P Although fire may be restricted to the desir‘ smoke and particulate matter carried into the sphere may be transported some distance burned area. Recognizing this as a potential Texas Air Control Board has developed -; 1 burning rangeland. A copy of the regulabhns p, i ofair fivm visibk emisswons’ and 7.1 matter can be obtained by writing the regional i‘ the Texas Air Control Board. I qI/leans within each column followed by the same letter do not dif- fer significantly lP 2 0.051, using Duncan's New Multiple Range Test. 12 I onmental conditions govern the effectiveness burning. Generally, relative humidity low since fire is faster and hotter in a drier . In the Coastal Prairie, however, relative typically higher than in most other regions of on this research, 5O to 7O percent relative acceptable as long as fuel moisture per- knot drastically increased. d is important in carrying the fire front Ing effective flame height. Based on this imum wind speed should range between imeters per hour. Maximum wind speed ed 29 kilometers per hour since excessive f reduce success by sweeping the fire too i?‘ vegetation and increasing the danger md burn will become a wildfire. Uni- fvelocity is desirable. Sometimes, gusty irate fire whirlwinds, creating “fire jicross fire lines. are characteristically drier, although can be executed with south winds of the area to be burned, for example, is along the south side, correct wind ~ to an advantage. Here, by burning he risk of smoke crossing the road is ntent of the vegetation may pre- oving uniformly across the area. two windy, sunny days following ‘ e to lower moisture to that re- rning. A small test area with a {er was ignited when it was un- ' moisture of the vegetation was sful burn. important for a successful burn a sps of the burn are dependent v ous fuel. The combustibil- ~ Macartney rose apparently with season. However, a herbaceous fuel carries a one Macartney rose clump a wide surrounding each i contained the fires in adequate amounts of ) was used for ig- ded at least a wind meter (wet and dry e humidity. A ey rose), head- burned into the plants had no previous improvement practices applied, a backfire of 31 meters was installed before lighting the headfire. An alternative plan is to backfire during moist weather. Backfiring in the fall to at least 31 meters fol- lowed by a winter headfire, for example, reduces the possibility that the fire will escape. After the backfire was ignited, the entire fire line was checked to insure uniform burning before authoriza- tion was given to light the headfire. Areas such as ber- mudagrass patches and cattle trails presented discon- tinuities in the fuel cover and were sometimes difficult to burn. These areas were re-ignited since they could later serve as fuel for the headfire. When the wind was perpendicular to.the fire line, only one side was ignited. Personnel began at the middle and ignited the fire front outward. Frequently, however, the wind was moving in a diagonal fashion. In these instances, personnel began backfiring at the leeward corner and progressed along each of the two sides (F ig- ure 3). A similar approach was taken for the headfire along the windward sides. This technique provided an even flame front which afforded few, if any, control prob- lems. As a general rule, burns were patrolled for 24 hours after burnout. Stumps, logs, bunchgrasses, and manure that continued to burn along the edge of the fire were ~ broken up to reduce fuel density. Special care was taken in extinguishing fires found in low areas such as in root systems below the soil surface. ¢——"ser BACKFIRE BACKFIRE IS'3OM RELATIVE HUMIDITY é 70% AIR TEMPERATURE ‘3I6C FIRELINE lfxiam WIDE) SET ___¢ HEADFIRE Figure 3. Fire plan as implemented for instaliation of burns on the Coastal Prairie during 1975-76. l3 DISCUSSION AND CONCLUSIONS Regardless of season, prescribed burning was effec- tive in initially removing the Macartney rose canopies and releasing range forage plants on the Coastal Prairie. Uniformity and speed of the fire front, within the narrow range of wind speeds used, was most influenced by total fine fuel load, moisture content of fine fuel, and propor- tion of dead standing herbaceous material in the fine fuel. Burning during the winter when warm season grasses, the majority of the fine fuel, were dormant, removed only the Macartney rose canopies and dead herbaceous material. Prescribed burning in the spring and summer, when the fine fuel content of green her- baceous material was higher, tended to reduce the rate of movement of the flame front and decreased uniformity of movement. Relighting of the green fine fiiel often was ' required to carry the fire front between Macartney rose clumps. Areas released from the Macartney rose canopy cover by burning immediately became available for grass and forb establishment, and livestock access to forage was improved. The fires did not, however, kill the Macartney rose, and basal sprouting occurred regardless of season of burning. Although canopy replacement av- eraged from 6 to 8 percent per month, canopy heights at 1.5 years following burning were much lower than pre- treatment heights. Also, much of the herbaceous top- growth within areas once occupied by the original canopy was still accessible for grazing use and was taller than the Macartney rose regrowth. The reduced canopy height of Macartney rose also facilitated handling of live- stock. In May 1976, cattle could easily be located with- out hindrance of the Macartney rose canopy on areas burned in February 1975. Season of burning Macartney rose-infested range- _ land was important to response of herbaceous vegeta- tion, both in production and composition, especially during the first growing season. Burning in the winter removed minimal amounts of green herbaceous top- growth, primarily of the relatively few cool-season species common to the area. Although burns installed after spring greenup burned slowly and unevenly, they removed established green forage which would other- wise have been available for grazing animals. Initiation of regrowth of forage species following spring and sum- mer burns occurred under hotter, drier conditions than following winter burns. Presumably, evaporation was 14 greater from the blackened surfaces with n; from mulch or shade from foliar cover. Altho ti"; in the fall allowed herbaceous regrowth to‘ cooler conditions with a greater probability I rainfall, herbaceous production was slow burns and subsequently restricted with the winter. However, from a management stan ing some areas in the fall could beFadVantagI moting animal condition prior to the w‘ period. Calving in October and November if demand for quality forage when the majori plants are mature and/ or entering dormancyf. Winter burning not only resulted in herbaceous production but evidently also p?‘ best conditions for forb establishment. Broay" baceous vegetation is an important compo stock diets but is a critical requirement for species. For instance, certain forbs are pri items of the white-tailed deer on Coastal deer tended to concentrate on areas burned i I especially those which were near protec Came birds such as dove (Zenaidura macri bobwhite quail, observed many times in I utilized seed from forbs such as Texas crotori burnings, various species of birds gathered flame front and fed on insects made easily mulch removal. In the spring months, fawnsi birds were observed using the burned areafii; Prescribed burning must be incorporatf ' the overall ranch plan for maximum etfecti.’ provisions for deferment following burning to successful improvement as fire itself. Us, ment is the time necessary for a grass plant-If’ to 6 true leaves under satisfactory growing only a portion of a fenced area is burned, rate should be adjusted to the burned a entire pasture. A second deferment perivdl, lowing winter burning, can be instrumental; establishment of herbaceous vegetation d celerated spring growth period. ACKNOWLEDGMENTS I The authors thank P. H. Welder for pro tance and land at the Welder Greenlake ' . research project. Also, they deeply apprecij of Orvin Bontrager, David Embry, Ray Hin Kelley, Lynn Kitchen, Herman Mayeux, je Iames Mutz, and David Oefinger in data . C., and A. R. Schmid. 1942. A study of the inclined point method of botanical analysis of pasture mixtures. Amer. on. Jour. 34:238-247. p R. H. 1941. Application of the line interception method “g range vegetation. Jour. Forestry 39:338-394. D. S., and M. C. Johnston. 1970. Manual of vascular Texas. p. 754. Texas Research Foundation, Renner, mire, R. 1967. Plants and Environment: A Textbook of tfutecology. John Wiley and Sons, Inc., New York. 422 p. ‘i A. J. 1975. The botanical and nutritive composition of ets of cattle grazing on the Texas gulf coast. MS Thesis. M University, College Station. 73 p. . W. 1975. Texas plants. A checklist and ecological sum- éxas Agr. Exp. Sta. MP-585. 121 p. , C. 0., R. H. Haas, and B. E. Jeter. 1964. Macartney n01 in Texas. Texas Agr. Exp. Sta. MP-745. 11 p. A. 1963. Fire — a tool, not a blanket rule in douglas-fir Proc. Tall Timbers Fire Ecol. Conf. 2:1-17 I, W. C., C. O. Hofllnan, and B. E. Jeter. 1959. Possibil- l trolling Macartney rose. Texas Agr. Exp. Sta. Prog. Rep. ;=p, I . A. 1963. Use of fire in wildlife management. Proc. Tall ire Ecol. Conf. 2:19-20. LITERATURE 11. 12. 13. 14. 15. 16. 17. 18. 19. Polk, D. B. Jr. 1974. Evaluation of four grasses for seeding on ‘ south Texas rangeland. MS Thesis, Texas A&M University, Col- lege Station. 61 p. Scifres, C. J. 1975. Systems for improving Macartney rose- infested Coastal Prairie rangeland. Texas Agr. Exp. Sta. MP-1225. 12 p. Scifres, C. J., G. P. Durham, and]. L. Mutz. 1977. Range forage production and consumption following aerial spraying of mixed brush. Weed Sci. 25:48-54. Stoddard, H. L., Sr. 1963. Bird habitat and fire. Proc. Tall Tim- bers FireEcol. Conf. 2:163-175. Stoddard, H. L., Sr. 1963. Maintenance and increase of the east- ern wild turkey on private lands of the coastal plain of the deep southeast. Bull. No. p3,: Tall Timbers Res. Sta. Tallahassee, Florida. 49 p. - Vallentine, J. F. 1971. Range development and improvements. Brigham Young Univ. Press., Provo, Utah. p. 15. Weaver, J. E., and N. W. Rowland. 1952. Effects of excessive natural mulch on development, yield and structure of native grassland. Bot. Caz. 114:1-19. Wright, H. A. 1968. Eflect of spring burning on tobosa grass. J. Range Manage. 22:425-427. Wright, H. A. 1974. Range burning. J. Range Manage. 27:5-11. a w w1~i»-~zr-" ‘~30 . r - §l--~.">%- 4, a A ~ All programs and information of The Texas Agricultural Experiment Station are available to everyone without regard to race, color, or national origin. The Texas Agricultural Experiment Station, I. E. Miller, Director, College Station, Texas 2.5M—11-77