Phanerogamic flora and phytogeography of the Cloud Dwarf Forests of Ibitipoca State Park, Minas Gerais, Brazil

Abstract: This study was developed in Ibitipoca State Park (ISP), a mountainous massif that stands out in the Serra da Mantiqueira, in the Southeastern Region of Brazil. The vegetation is represented by a phytophysiognomic mosaic where areas of campos rupestres interspersed with cloud dwarf forests predominate, at altitudes of 1100 to 1700 m.s.m. The cloud dwarf forests exist in narrow altitude belts on the mountain peaks, immersed in a layer of clouds. They form a peculiar landscape high in the mountains by the short stature of the arboreal elements and richness of lichens and bryophytes, which develop under constant condensation of humidity, low temperatures, and frequent winds. The objective of the present work was to determine the floristic composition and phytogeography of the cloud dwarf forests of ISP. Twelve monthly campaigns were conducted to collect botanical material during the years 2014 and 2015. The collected material was deposited in the collection of the CESJ Herbarium. A total of 372 species, 209 genera, and 73 families of phanerogams were found. The richest families were Orchidaceae (84 spp.), Asteraceae (39 spp.), and Melastomataceae (21 spp). The genera with the greatest wealth were Leandra (09 spp.), Epidendrum (09 spp.), Pleurothallis (09 spp.), Mikania (07 spp.), and Miconia (07 spp). The arboreal habit was predominant with 103 species (27.7%), followed by 83 shrubs (22.3%), 82 epiphytic herbs (22%), 80 terrestrial herbs (21.5%), and 23 lianas (6.5%). The floristic composition presents elements typical of altitude vegetation, including species of campos rupestres and high epiphytes richness, especially of the families Orchidaceae and Bromeliaceae. The genera with tropical distribution represent 86.5%, whereas the temperate elements represent 13.5% of the total. The cloud dwarf forests presented similarity, at the family and gender levels, with the upper montane forests of the Andes, besides phytogeographic characteristics that allow to associate them to a transition environment between the campos rupestres and the upper montane forests of the Southeast Region of Brazil.摘要：本研究于巴西东南部曼蒂凯拉山脉（Serra da Mantiqueira）内的标志性山地地块——伊比蒂波卡州立公园（Ibitipoca State Park, ISP）开展。该区域的植被以植物群落镶嵌体为典型特征，其中海拔1100至1700米的岩生草原（campos rupestres）与云雾矮林交错分布的区域占据主导。云雾矮林分布于山峰的狭窄海拔带内，常年被云雾包裹。由于林木组分低矮、地衣与苔藓植物繁盛，且生境持续处于水汽凝结、低温且多风的环境中，形成了山地特有的独特景观。本研究旨在明确伊比蒂波卡州立公园云雾矮林的区系组成与植物地理特征。2014至2015年间，共开展12次月度野外调查以采集植物标本，所获标本均存放于CESJ植物标本馆。本次调查共记录显花植物73科、209属、372种。物种丰富度最高的科为兰科（Orchidaceae，84种）、菊科（Asteraceae，39种）与野牡丹科（Melastomataceae，21种）；物种数量最多的属为Leandra（9种）、Epidendrum（9种）、Pleurothallis（9种）、Mikania（7种）与Miconia（7种）。生活型组成方面，木本习性物种占比最高，计103种（27.7%），其次为灌木83种（22.3%）、附生草本82种（22%）、陆生草本80种（21.5%），藤本23种（6.5%）。该区系包含典型的高海拔植被类群，兼具岩生草原物种与极高的附生植物丰富度，尤以兰科与凤梨科（Bromeliaceae）类群为代表。其中热带分布属占总属数的86.5%，温带分布属占比13.5%。从科与属的分类单元来看，该云雾矮林与安第斯山脉的山地上部森林具有类群相似性，同时其植物地理特征表明其属于巴西东南部岩生草原与山地上部森林之间的过渡生境。