Arboriculture & Urban Forestry 39(5): September 2013 215 Table 3. Effects of transplanting method on selected growth parameters of transplanted eldarica pine (Pinus eldarica), white mulberry (Morus alba), and smoothleaf elm (Ulmus carpinifolia) trees during the first (2010) and second (2011) years following transplanting. Measurements were conducted in October of each year. Species Eldarica pine White mulberry Smoothleaf elm Eldarica pine White mulberry Smoothleaf elm z Transplanting method BR B&B BR B&B BR B&B BR B&B BR B&B BR B&B of fresh weight. Shoot length (cm) 2010 6.9 by 10.6 a 19.8 a 19.2 a 7.0 a 6.8 a 2011 5.3 a 4.8 a 5.7a 7.7 a 4.3 a 2.9 a 5.7 a 7.3 a 8.9 a 7.8 a 7.1 a 5.2 a - - - - - - 10.8 a 12.4 a 12.6 a 13.2 a 16.2 a 17.0 a For white mulberry and smoothleaf elm trees, mean leaf chlorophyll content was measured by SPAD meter readings, while for eldarica pine trees it was determined spec- troscopically and presented as mg g-1 y Treatment means within column in each year followed by the same letter are not significantly different (Duncan’s multiple-range test) at 5% level. luteola) and Dutch elm disease (Ophiostoma novo-ulmi) has severely compromised elm tree growth and vitality in Isfahan. Low survival rate has been reported for trees and shrubs trans- planted in dry climates. Transplanted honey mesquite (Prosopis glandulosa) seedlings in the arid Sonoran Desert (California, U.S.) showed 77% mortality after 3.5 years (Bainbridge et al. 2001). For all three species, trees planted as B&B had significantly greater percent survival, suggesting that B&B transplanting of studied tree species may be less stressful and lead to bet- ter establishment than BR transplanting. Nevertheless, con- flicting observations have been published on transplanting success of B&B and BR trees and it seems to be dependent on tree species and regional climate, in addition to cultural prac- tices and post-transplant care. For instance, B&B transplanted American hophornbeam (Ostrya virginiana) reached 100% survival two year after transplanting, while BR trees showed high rate of mortality (50%). B&B transplanted hackberry (Celtis occidentalis) trees also had greater (10% larger) sur- vival than BR trees, whereas for swamp white oak (Quercus bicolor) no substantial impact was observed for transplanting method (Buckstrup and Bassuk 2000). Most recently, Anella et al. (2008) reported no significant difference in mortality of B&B and BR stocks of Platanus × acerfolia, Acer × free- manii, and Taxodium distichum, in the more drought-inclined environment of Oklahoma, U.S. Similar results on 10 urban street species have been reported by Jack-Scott (2012). While B&B transplanting method increased survival rate of studied species compared to BR transplanting, its impact on different growth parameters was less impres- sive except for trunk diameter. In all three species, B&B transplanted trees had higher RGRD than their BR counter- parts. The same result was obtained by Ross (2008), who showed that B&B transplanted Platanus × acerfolia trees had significantly greater RGRD than BR trees of similar size. Findings of another study on some street tree species agreed with results of present study (Watson et al. 1986). By the end of second year, most of the significant differ- ences observed for tree survival and growth parameters disap- peared. This is consistent with Buckstrup and Bassuk (2000) and Vanstone and Ronald (1981) who found that first year effects of transplanting method did not persist into the second year. Reduced growth of current-season shoots is one of the most important indicators of transplant shock (Watson et al. 1986; Sturve et al. 2000). This is mainly due to insufficient supply of water and nutrition, as well as reduction in root-produced hor- mones necessary for vigorous shoot extension (Hinesly 1986). Shoot growth reduction is mostly species dependent and may last for few years following transplanting, until replacement of new root system (Watson et al. 1986; Ross 2008). In the present study, shoot growth significantly decreased during the first two years after transplanting. However, rapid increase in annual shoot growth was observed by the third year, so the growth rate of eldarica pine and smoothleaf elm trees came to equal that of untransplanted tress. Therefore, it seems eldarica pine and smoothleaf elm trees have almost been established during three years, while white mulberry trees require more time for complete establishment. In the present study, the effect of transplanting date and method on growth and survival of three urban tree species were examined in order to determine the appropriate transplanting conditions of these species. This is crucial for maintaining and protecting valu- able urban trees in arid and semiarid climates. Based on the data, early-winter transplanting for white mulberry and smoothleaf elm trees and early-spring transplanting for eldarica pine trees resulted in greater survival rate and are therefore considered as the best time of the year for transplanting the aforementioned trees in the Isfahan landscape. In the first year following transplanting, the B&B method conferred advantage over BR method for sur- vival of transplanted trees but its impact on different growth indi- ces was not significant. Also, post-transplant growth differences observed between B&B and BR trees did not continue in subse- quent year, suggesting that final performance of BR trees may be equal to their B&B counterparts. Further research is needed both to understand the long-term effects of the different treatments and also to determine optimal transplanting methods for each species. Acknowledgments. The authors would like to appreciate Parks and Landscape Organization of Isfahan Municipality for financial support of this research. ©2013 International Society of Arboriculture 5.8 b 7.6 a 8.6 a 9.1 a 5.0 a 5.0 a 3.4 a 3.1 a 5.4 a 6.3 a 3.7 a 2.3 b 7.5 a 8.9 a 16.4 a 16.8 a 13.0 a 12.6 a Shoot number Dieback (cm) Chlorophyll contentz
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