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）知名的山地地块——伊比蒂波卡国家公园（Ibitipoca State Park, ISP）开展。该区域植被以植物群落镶嵌体为特征，其中岩生草原（campos rupestres）与云雾矮林（cloud dwarf forests）交错分布的区域占主导，分布海拔为1100至1700米（m.s.m.）。云雾矮林分布于山峰狭窄的海拔带内，常年被云雾笼罩；其乔木组分低矮、地衣与苔藓类植物丰富，在持续水汽凝结、低温与强风的生境中生长，形成了山地特有的高海拔景观。

本研究的目的是明确伊比蒂波卡国家公园云雾矮林的区系组成与植物地理特征。研究于2014至2015年间开展了12次月度野外调查，采集植物标本，所有采集的标本均馆藏于CESJ植物标本馆（CESJ Herbarium）。

本次调查共记录显花植物（phanerogams）73科209属372种。物种丰富度位居前三的科分别为兰科（Orchidaceae，84种）、菊科（Asteraceae，39种）与野牡丹科（Melastomataceae，21种）；属内物种数位居前列的类群包括Leandra属（Leandra，9种）、树兰属（Epidendrum，9种）、Pleurothallis属（Pleurothallis，9种）、薇甘菊属（Mikania，7种）以及野牡丹属（Miconia，7种）。

乔木类群占比最高，共计103种（占总物种数的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%）以及藤本23种（6.5%）。

该区域的区系包含高海拔植被的典型类群，包括岩生草原（campos rupestres）物种以及物种丰富度极高的附生植物，尤以兰科（Orchidaceae）与凤梨科（Bromeliaceae）类群为突出。热带分布属占总属数的86.5%，温带分布属占比为13.5%。

从科与属的分类层级来看，该云雾矮林与安第斯山脉的山地上部森林（upper montane forests）具有类群相似性；结合其植物地理特征，可将其归为巴西东南部岩生草原与山地上部森林之间的过渡生境。