{"title":"原生松稀树草原地表微生境对长叶松供种的影响","authors":"M. Blanchard, W. Platt","doi":"10.1637/0003-0031-185.1.15","DOIUrl":null,"url":null,"abstract":"Abstract. Globally, savanna trees experience bottlenecks to recruitment. Likelihoods are low that juveniles, especially of nonclonal, reseeder species, will survive and reach sizes that survive recurrent fires. We hypothesized if ground layer vegetation within savannas contained patches with reduced fire effects, likelihoods of juvenile trees surviving fires would be increased. We refined our general hypothesis based on a field study in an old-growth southeastern pine savanna of North America, in which longleaf pine (Pinus palustris Mill.) is the most abundant tree. We hypothesized that recruitment of pines into the fire-resistant ‘grass stage’ may be more likely in three ground layer microhabitats (inside crowns of fallen pines, around pine tree stumps, and inside patches of oak/hardwood stems) than in surrounding groundcover located away from overstory pines. We measured the composition and abundance of ground layer vegetation and censused juvenile grass stages (< 1.5 m height) of longleaf pine in plots in replicated patches of these three microhabitats and in the surrounding ground layer matrix, all located away from large trees. Ground layer vegetation was less abundant inside than outside the three microhabitats and abundances of grasses and shrubs differed among microhabitats. A zero-inflated Poisson model indicated that occurrence of grass stage longleaf pines was >5 times more likely inside the three microhabitats than in the surrounding ground layer matrix. Recruitment was also more likely in pine than oak/hardwood microhabitats. We propose that altered microhabitats, especially those generated by death of large longleaf pines, likely facilitate recruitment into populations of this reseeding savanna tree.","PeriodicalId":50802,"journal":{"name":"American Midland Naturalist","volume":"185 1","pages":"15 - 31"},"PeriodicalIF":0.6000,"publicationDate":"2021-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":"{\"title\":\"Ground Layer Microhabitats Influence Recruitment of Longleaf Pine in an Old-growth Pine Savanna\",\"authors\":\"M. Blanchard, W. Platt\",\"doi\":\"10.1637/0003-0031-185.1.15\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract. Globally, savanna trees experience bottlenecks to recruitment. Likelihoods are low that juveniles, especially of nonclonal, reseeder species, will survive and reach sizes that survive recurrent fires. We hypothesized if ground layer vegetation within savannas contained patches with reduced fire effects, likelihoods of juvenile trees surviving fires would be increased. We refined our general hypothesis based on a field study in an old-growth southeastern pine savanna of North America, in which longleaf pine (Pinus palustris Mill.) is the most abundant tree. We hypothesized that recruitment of pines into the fire-resistant ‘grass stage’ may be more likely in three ground layer microhabitats (inside crowns of fallen pines, around pine tree stumps, and inside patches of oak/hardwood stems) than in surrounding groundcover located away from overstory pines. We measured the composition and abundance of ground layer vegetation and censused juvenile grass stages (< 1.5 m height) of longleaf pine in plots in replicated patches of these three microhabitats and in the surrounding ground layer matrix, all located away from large trees. Ground layer vegetation was less abundant inside than outside the three microhabitats and abundances of grasses and shrubs differed among microhabitats. A zero-inflated Poisson model indicated that occurrence of grass stage longleaf pines was >5 times more likely inside the three microhabitats than in the surrounding ground layer matrix. Recruitment was also more likely in pine than oak/hardwood microhabitats. We propose that altered microhabitats, especially those generated by death of large longleaf pines, likely facilitate recruitment into populations of this reseeding savanna tree.\",\"PeriodicalId\":50802,\"journal\":{\"name\":\"American Midland Naturalist\",\"volume\":\"185 1\",\"pages\":\"15 - 31\"},\"PeriodicalIF\":0.6000,\"publicationDate\":\"2021-01-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"5\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"American Midland Naturalist\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://doi.org/10.1637/0003-0031-185.1.15\",\"RegionNum\":4,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"Agricultural and Biological Sciences\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"American Midland Naturalist","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1637/0003-0031-185.1.15","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Agricultural and Biological Sciences","Score":null,"Total":0}
Ground Layer Microhabitats Influence Recruitment of Longleaf Pine in an Old-growth Pine Savanna
Abstract. Globally, savanna trees experience bottlenecks to recruitment. Likelihoods are low that juveniles, especially of nonclonal, reseeder species, will survive and reach sizes that survive recurrent fires. We hypothesized if ground layer vegetation within savannas contained patches with reduced fire effects, likelihoods of juvenile trees surviving fires would be increased. We refined our general hypothesis based on a field study in an old-growth southeastern pine savanna of North America, in which longleaf pine (Pinus palustris Mill.) is the most abundant tree. We hypothesized that recruitment of pines into the fire-resistant ‘grass stage’ may be more likely in three ground layer microhabitats (inside crowns of fallen pines, around pine tree stumps, and inside patches of oak/hardwood stems) than in surrounding groundcover located away from overstory pines. We measured the composition and abundance of ground layer vegetation and censused juvenile grass stages (< 1.5 m height) of longleaf pine in plots in replicated patches of these three microhabitats and in the surrounding ground layer matrix, all located away from large trees. Ground layer vegetation was less abundant inside than outside the three microhabitats and abundances of grasses and shrubs differed among microhabitats. A zero-inflated Poisson model indicated that occurrence of grass stage longleaf pines was >5 times more likely inside the three microhabitats than in the surrounding ground layer matrix. Recruitment was also more likely in pine than oak/hardwood microhabitats. We propose that altered microhabitats, especially those generated by death of large longleaf pines, likely facilitate recruitment into populations of this reseeding savanna tree.
期刊介绍:
The American Midland Naturalist has been published for 90 years by the University of Notre Dame. The connotations of Midland and Naturalist have broadened and its geographic coverage now includes North America with occasional articles from other continents. The old image of naturalist has changed and the journal publishes what Charles Elton aptly termed "scientific natural history" including field and experimental biology. Its significance and breadth of coverage are evident in that the American Midland Naturalist is among the most frequently cited journals in publications on ecology, mammalogy, herpetology, ornithology, ichthyology, parasitology, aquatic and invertebrate biology and other biological disciplines.