Cattle grazing and pine survival and growth in subterranean clover pasture |
| |
| Authors: | H A Pearson V C Baldwin J P Barnett |
| |
| Institution: | (1) USDA Forest Service, Southern Forest Experiment Station, 71360 Pineville, Louisiana, USA |
| |
| Abstract: | When combining pines and cattle on tame pasture, grazing is often delayed for several years until trees are large enough to
resist injury. As an alternative approach to delayed or deferred grazing during the early years, this study in central Louisiana,
USA, examined the effects of cattle grazing in subterranean clover (Trifolium subterraneum L.) pastures on slash (Pinus elliottii Engelm.) and loblolly pine (P. taeda L.) seeding survival and growth during the first 3 years of tree establishment. Pines were planted at about 1200 trees/ha
in 3 rows on 0.4-ha subclover units with 1.3 m spacing within rows. Three grazing treatments included: (1) ungrazed pines,
(2) limited grazing with a single-wire electric fence above the planted pines, and (3) grazed pines. Thirty Brahman crossbred
cows with calves and a bull grazed the tame pasture on a controlled grazing, rotational basis from December through May each
year, during the subterranean clover growing season. Pine trampling injury during the year was 8% on the grazed seedlings
while essentially none occured under limited grazing. During the first 2 growing seasons, survival and height of the pines
were significantly less on the grazed seedlings than on either the limited grazing or ungrazed seedlings. Pine heights from
the limited grazing and ungrazed treatments were not different during the 3-year study; loblolly pine heights from the limited
grazing treatment continued to be taller than the grazed treatment through the third year while the slash pine heights were
similar for all treatments by the third year. Seedling mortality became more acute as severity of grazing injury increased;
the greatest mortality occured when the terminal bud and needles were both browsed off. |
| |
| Keywords: | Agroforestry electric fence injury loblolly pine slash pine |
| 本文献已被 SpringerLink 等数据库收录！ |
|
