plants Article Natural and Historical Heritage of the Lisbon Botanical Gardens: An Integrative Approach with Tree Collections Ana Raquel Cunha 1,2,† , Ana Luísa Soares 2,3,† , Miguel Brilhante 1 , Pedro Arsénio 1 , Teresa Vasconcelos 4, Dalila Espírito-Santo 1 , Maria Cristina Duarte 5 and Maria Manuel Romeiras 1,5,* 1 Linking Landscape, Environment, Agriculture and Food (LEAF), Instituto Superior de Agronomia (ISA), Universidade de Lisboa, Tapada da Ajuda, 1340-017 Lisboa, Portugal; [email protected] (A.R.C.); [email protected] (M.B.); [email protected] (P.A.); [email protected] (D.E.-S.) 2 Research Centre in Biodiversity and Genetic Resources (CIBIO/InBIO), School of Agriculture, University of Lisbon, Tapada da Ajuda, 1349-017 Lisbon, Portugal; [email protected] 3 Jardim Botânico da Ajuda, Instituto Superior de Agronomia (ISA), Universidade de Lisboa, Calçada da Ajuda, 1300-011 Lisboa, Portugal 4 Instituto Superior de Agronomia (ISA), Universidade de Lisboa, Calçada da Ajuda, 1300-011 Lisboa, Portugal; [email protected] 5 Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; [email protected] * Correspondence: [email protected] † Equal contribution as first author. Abstract: Botanical gardens have long contributed to plant science and have played a leading role in Citation: Cunha, A.R.; Soares, A.L.; ex situ conservation, namely of threatened tree species. Focusing on the three botanical gardens of Brilhante, M.; Arsénio, P.; Lisbon (i.e., Botanical Garden of Ajuda—JBA, Lisbon Botanical Garden—JBL, and Tropical Botanical Vasconcelos, T.; Espírito-Santo, D.; Garden—JBT), this study aims to reveal their natural heritage and to understand the historical Duarte, M.C.; Romeiras, M.M. motivations for their creation. Our results showed that these gardens contain a total of 2551 tree Natural and Historical Heritage of specimens, corresponding to 462 taxa, within 80 plant families. Of these, 85 taxa are found in the the Lisbon Botanical Gardens: An Integrative Approach with Tree three gardens, and more than half of the taxa are hosted in JBL (334 taxa), whereas 230 and 201 taxa Collections. Plants 2021, 10, 1367. were recorded in JBT and JBA, respectively. The motivations for the creation of each garden are https://doi.org/10.3390/ reflected in the different geographic origins of the trees they host in their living collections. The plants10071367 Palearctic species are dominant in JBA and JBL, and Tropical trees prevail in JBT. With more than 250 years of history, these gardens hold an invaluable natural and historical heritage, with their Academic Editor: Cássio Van den living collections providing valuable sources of information for the conservation of threatened plant Berg species, at local and global scales. Received: 21 May 2021 Keywords: historical heritage; living trees collections; Portugal; spermatophytes; trees; conservation; Accepted: 1 July 2021 urban green spaces Published: 4 July 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in 1. Introduction published maps and institutional affil- iations. Biodiversity loss is a global phenomenon [1]. Adding to the conservation of species diversity in their natural habitats, the loss and degradation of urban environments made the preservation of urban ecosystems and the promotion of their biodiversity particularly important since the beginning of the 21st century [2]. Many cities still include remains of previous forests and trees that should be actively managed and preserved, namely in urban Copyright: © 2021 by the authors. parks or woodlots [3]. Moreover, botanical and environmental awareness will be better Licensee MDPI, Basel, Switzerland. This article is an open access article raised among the community by providing education and places to learn about the plants distributed under the terms and and their conservation, and the botanical gardens play a relevant role in this context [4,5]. conditions of the Creative Commons Botanical gardens are institutions that keep well-documented collections of living Attribution (CC BY) license (https:// plants and seed banks, and are thus fundamental for conservation, education, and sci- creativecommons.org/licenses/by/ ence [6,7]. Since the 1970s, the conservation of species outside their natural habitat (ex 4.0/). situ conservation), namely of threatened tree species, is encouraged by the International Plants 2021, 10, 1367. https://doi.org/10.3390/plants10071367 https://www.mdpi.com/journal/plants Plants 2021, 10, x FOR PEER REVIEW 2 of 30 Plants 2021, 10, 1367 2 of 29 [6,7]. Since the 1970s, the conservation of species outside their natural habitat (ex situ conservation), namely of threatened tree species, is encouraged by the International Union for Conservation of Nature (IUCN) and Botanic Gardens Conservation International Union(BGCI) for [8]. Conservation As unique urban of Nature green (IUCN) spaces, and the Botanic botanical Gardens gardens Conservation offer the Internationalpotential to (BGCI)restore [populations8]. As unique of threatened urban green species, spaces, as thetheir botanical living collections gardens offerand seed the potential banks are to restoreinsurance populations against the of extinction threatened of species,species in as their their natural living habitats collections and and provide seed means banks areto insurancereintroduce against or reinforce the extinction their populations of species ther in theireby making natural their habitats survival and providepossible means[9,10]. to reintroduceIn plant or conservation, reinforce their trees populations are widely thereby recognized making as critically their survival important possible to the [planet9,10]. and Inpopulation plant conservation, at the economic, trees are widelycultural, recognized and ecological as critically levels important [7]. However, to the planettheir andnumbers population have been at the declining economic, in cultural,situ due to, and e.g., ecological climate levelschange, [7 ].overgrazing, However, their agriculture, numbers haveand logging been declining [11]. According in situ dueto the to, IUCN e.g., Red climate List, change, ca. 10,000 overgrazing, tree species agriculture, are threatened and loggingwith extinction [11]. According worldwide to the[12]. IUCN Several Red studie List, ca.s have 10,000 also tree recognized species are that threatened trees are key with extinctionelements in worldwide urban nature, [12]. Severalas their studies presence have provides also recognized numerous that services trees are to key the elements urban inecosystem urban nature, in ecological as their presence(i.e., climate, provides air numerousquality, hydrology, services to soil, the urbanand biodiversity ecosystem in ecologicalconservation), (i.e., social, climate, cultural, air quality, and aesthetic hydrology, terms soil, [13]. and biodiversity conservation), social, cultural,Lisbon, and aestheticcapital of terms Portugal, [13]. has unique characteristics owing to its location in SouthwestLisbon, Europe, capital in of a Portugal,transition haszone unique between characteristics the Atlantic Ocean owing and to its the location Mediterranean in South- westSea, and Europe, between in a Africa transition and zoneEurasia, between which the allows Atlantic it to host Ocean a higher and the average Mediterranean biodiversity Sea, andthan between other European Africa and cities Eurasia, [14]. whichAccording allows to it the to host municipality, a higher average Lisbon biodiversity has about 148 than othergardens European and parks, cities among [14]. which According are three to the bota municipality,nical gardens: Lisbon Botani hascal about Garden 148 of gardens Ajuda and(hereafter, parks, amongJBA), Lisbon which Botanical are three Garden botanical (her gardens:eafter, JBL), Botanical and Tropical Garden ofBotanical Ajuda (hereafter, Garden JBA),(hereafter, Lisbon JBT) Botanical (see Figure Garden 1), all (hereafter, of them belo JBL),nging and to Tropical the University Botanical of GardenLisbon. Lisbon (hereafter, is JBT)the only (see city Figure in Portugal1), all of themhousing belonging three botani to thecal University gardens, and of Lisbon. they hold Lisbon a rich is thenatural only and city inhistorical Portugal heritage, housing a three valuable botanical scientific gardens, resource and they to holdpromote a rich interdisciplinary natural and historical research her- itage,activities a valuable between scientific the different resource schools to promote of the interdisciplinary University, as researchwell as activitieswith worldwide between theinstitutions different interested schools of in the the University, study of as pl wellant diversity as with worldwide and conservation. institutions These interested three inbotanical the study gardens of plant are diversity very different, and conservation. created at different These threetimes botanicalbut with common gardens areoverall very different,purposes: createdresearch, at plant different conservation, times but hortic withulture, common and overall education. purposes: Surely, research, the study plant of conservation,these gardens horticulture, and of their and collections education. would Surely, enhance the study the ofcurrent these gardensunderstanding and of theiron collectionsGarden Art would History enhance and Plant the currentDiversity, understanding but the knowledge on Garden of this