Post-fire resprouting of shortleaf pine is facilitated by a morphological trait but fire eliminates shortleaf×loblolly pine hybrid seedlings

نویسندگان

  • J. C. Bradley
  • C. D. Nelson
چکیده

Concurrent with fire exclusion, shortleaf pine loblolly pine hybrids have increased throughout the southeastern USA and may threaten the genetic integrity of shortleaf pine. Historically, fire favored shortleaf pine over other southern pine species, especially loblolly pine, with which it shares a broad sympatric natural range. Shortleaf pine seedlings have a morphological adaptation (basal crook) that lowers dormant buds to the soil surface where they are presumably protected from fire to facilitate resprouting after topkill. To evaluate this presumption, we tested (1) the functional role of the basal crook in protecting dormant buds by measuring resprouting after exposing the lower stem of shortleaf pine to fire and protecting from fire the lower stem (and dormant buds) of loblolly pine (which lacks a basal crook) and (2) the occurrence and importance of the basal crook morphological adaptation in F1 shortleaf loblolly pine seedlings by comparing morphology and post-fire resprouting of the hybrids to both parents. Fire exposure of shortleaf pine seedling dormant buds caused seedling mortality, while protecting loblolly pine dormant buds facilitated resprouting. Hybrid pines have basal crooks intermediate to the strong crook of shortleaf pine and loblolly pine’s non-crooked stem. Fire top-killed loblolly pine and shortleaf loblolly pine seedlings, and they did not resprout, while 57% of shortleaf pine resprouted after topkill during two dormant season and one growing season burns. This highly significant difference shows that the basal crook is important for shortleaf pine resprouting after topkill by fire. Fire is an important tool to reduce shortleaf loblolly pine hybrids, and to provide a competitive advantage to shortleaf pine relative to loblolly pine, for ecosystem restoration and maintaining the genetic integrity of shortleaf pine. 2016 Elsevier B.V. All rights reserved.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

SHORT COMMUNICATION Frequent fire protects shortleaf pine (Pinus echinata) from introgression by loblolly pine (P. taeda)

Across much of the globe, fire is a major disturbance agent of forest and grassland communities. The removal of fire from previously fire-maintained ecosystems, which has occurred in many areas, changes species composition, favoring later less fire tolerant species over fire-adapted ones. A recent measured increase in the rate of hybridization between the fire-adapted shortleaf pine (Pinus echi...

متن کامل

Occurrence of Shortleaf Loblolly Pine Hybrids in Shortleaf Pine Orchards: Implications for Ecosystem Restoration

Shortleaf pine (Pinus echinata Mill.) is an important conifer in much of the southeastern United States. However, the species and its associated ecosystems are in decline, and recent evidence about hybridization with loblolly pine (Pinus taeda L.) raises concerns that the species may be at risk of further losses due to introgression. Although shortleaf pine is not widely planted for timber prod...

متن کامل

Hybridization Leads to Loss of Genetic Integrity in Shortleaf Pine: Unexpected Consequences of Pine Management and Fire Suppression

hybridization is normally prevented by different flowering times in the two species, but under certain climatic/weather conditions hybridization may occur (Dorman and Barber 1956), and natural hybrids of shortleaf pine and loblolly pine have been reported (Zobel 1953, Hare and Switzer 1969, Edwards-Burke et al. 1997 and Stewart et al. 2010). The questions are where, when, and why do they hybrid...

متن کامل

The Sprouting Potential of Loblolly and Shortleaf Pines: Implications for Seedling Recovery from Top Damage

Loblolly (Pinus taeda L.) and shortleaf (P. echinata Mill.) pine seedlings are frequently top damaged during their frst few years by browsing animals, insects, or forestry operations, but little quantitative information exists on the factors affecting recovery. Thus, we conducted two separate studies to evaluate potential recovery of seedlings from top damage under controlled conditions. The fi...

متن کامل

Factors affecting the sprouting of shortleaf pine rootstock following prescribed fire

Shortleaf pine (Pinus echinata) is a fire dependent species that is declining across the southeastern US. Its unique basal crook is an adaptation that protects dormant buds from fire and facilitates prolific sprouting of seedling rootstocks following top-kill. Understanding what influences shortleaf pine sprouting after fire could greatly increase success of natural regeneration efforts. We exa...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2016