Journal of Arid Environments 126 (2016) 12e22 Contents lists available at ScienceDirect Journal of Arid Environments journal homepage: www.elsevier.com/locate/jaridenv Vegetation of Bosque Fray Jorge National Park and its surrounding matrix in the Coastal Desert of north-central Chile * Francisco A. Squeo a, b, , Andrea P. Loayza a, Ramiro P. Lopez a, Julio R. Gutierrez a, b a Departamento de Biología, Universidad de La Serena and Instituto de Ecología y Biodiversidad (www.ieb-Chile.cl), Casilla 554, La Serena, Chile b Centro de Estudios Avanzados en Zonas Aridas (www.ceaza.cl), Chile article info abstract Article history: Within its almost 9000 ha, Bosque Fray Jorge National Park (BFJNP) possesses a natural mosaic of Received 20 February 2015 vegetation formations dominated by thorn scrub (63.3% of the park) and scrub with cacti and other Received in revised form succulents (34.1%); these formations, whose plant covers are above 40%, are representative of the Coastal 7 October 2015 Desert vegetation. Additionally, BFJNP has 230 ha (2.6%) of a relict fog forest. This unique combination of Accepted 16 October 2015 vegetation formations, partly explains the high plant species richness of the park. We discuss the climatic Available online 21 December 2015 and topo-edaphic factors associated with each type of vegetation formation. Compared to BFJNP, the surrounding vegetation matrix shows evidence of changes in both the Keywords: fl Plant diversity dominant vegetation and their plant covers; moreover, it is oristically depauperate relative to the park. Plant community This territory also includes agricultural land and plantations of non-native shrubs, as well as goat herding Land cover and small, inter-dispersed human settlements. Its main land cover types are: scrub (50%), scrub with Relict fog forest succulents (34%), agricultural land (8%), secondary prairies (3.5%), and plantations of non-native shrubs Conservation (1.6%). Approximately 22% of this area presents high levels of anthropization. Additionally, two wind farms (217 wind turbines) have begun operating within the vicinity of BFJNP within the past two years. BFJNP provides more than a mere representative sample of the current vegetation; it constitutes a remnant of the natural vegetation that once dominated the Coastal Desert before European colonization. Whereas the relict fog forest has been historically isolated, the desert vegetation is increasingly losing connectivity outside the park. We discuss the consequences of this isolation in terms of long-term maintenance of biodiversity. We argue that plant communities at BFJNP are the best available model for ecological restoration projects in this region of Chile. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction cartography originally used to delimit the park. BFJNP is divided into two unequal subsections (Fig. 1): the main area (8880 ha, Fray Bosque Fray Jorge National Park (BFJNP) is located on the coast Jorge hereafter) is located to the north of the Limarí River, whereas of the Coquimbo Region, Chile, just south of the Atacama Desert. It the second area (114 ha, Talinay henceforth) is located on the was declared a National Park in 1941 and a World Biosphere hilltop of Cerro Talinay, south of the Limarí River. Reserve in 1977. In 1981, three National Parks (Bosque Fray Jorge, During the late Miocene, BFJNP was completely underwater and Punta del Viento and Talinay) merged to create what is currently presently contains a series of marine terraces that reflect tectonic BFJNP (CONAF, 1998). The official area of BFJNP reported by CONAF blocks of recent geologic origin, and which have sustained torren- (1998) is 9959 ha; however, the most recent spatial data reveals a tial erosion dynamics (Novoa-Jerez et al., 2004a). There are three current size of approximately 8994 ha (CONAF, 2004). This distinct geomorphological units in BFJNP (from west to east): 1) the discrepancy can be attributed to changes in the boundaries of coastal terrace (uplifted during the PlioceneePleistocene); 2) the neighboring human communities and/or from different coastal massif of Altos de Talinay (reaching heights of up to 660 m a.s.l.) and; 3) tilted blocks forming hills and dry ravines that include Quebrada de Las Vacas (formed during the Pliocene). Altos de Talinay started uplifting during the Pliocene and reached its * Corresponding author. Departamento de Biología, Universidad de La Serena, maximum height in the Pleistocene (Paskoff, 1993; Novoa-Jerez Casilla 554, La Serena, Chile. E-mail address: [email protected] (F.A. Squeo). et al., 2004a). A submarine trench of 1000 m is located http://dx.doi.org/10.1016/j.jaridenv.2015.10.013 0140-1963/© 2015 Elsevier Ltd. All rights reserved. F.A. Squeo et al. / Journal of Arid Environments 126 (2016) 12e22 13 Fig. 1. Location of Bosque Fray Jorge National Park (BFJNP). The official boundary is shown as a continuous white line, roads are shows as black (paved) or thin black dashed (dirt or gravel) lines, and the 10 and 3 km buffers around Fray Jorge and Talinay, respectively, are shown as white dashed lines. 14 F.A. Squeo et al. / Journal of Arid Environments 126 (2016) 12e22 approximately 10 km from the coast, and runs parallel to Altos de Cerro Juan Soldado and El Tofo, which are 150 km north of Fray Talinay. Jorge, contain small fog-dependent relict populations of Kageneckia oblonga (Bollen); a small tree that is abundant in the periphery of 2. Origin of the flora of Bosque Fray Jorge National Park relict 0livillo forests at BFJNP and common in the Andes of central Chile. Perturbation regimes in the Pleistocene and Holocene also The woody components of Bosque Fray Jorge originate from affected the genetic diversity of shrub populations. For example, Paleogene flora, which corresponds to tropical lineages with Aus- Colliguaja odorifera populations located in the coastal mountain tralasian links that inhabited the southern portion of the South range have higher genetic diversity than populations in the Andes American continent before the breakup of occidental Gondwana of central Chile, suggesting the former may have been refuges (Bull- ~ (Villagran et al., 2004). Events that occurred at the end of the Ter- Herenu et al., 2005). tiary, such as the glaciation of occidental Antarctica and Patagonia, As a result of the mixing of these distinct floras (e.g., xeric lin- the formation of the Humboldt Current, the final uplift of the eages from the north and more mesic lineages from central and Andes, and the increase in aridity of the Atacama Desert, led to a southern Chile), the Coquimbo Region has the highest plant di- fragmentation and shrinkage of the northern edge of subtropical versity in Chile (Squeo et al., 2012). The xerophytic flora has ele- forests of the Pacific Coast and to the expansion of subtropical ments as old as those in the relict forest; some originated from the sclerophyllous forests of central Chile. These events would have ancient sclerophyllous forest of central Chile, whereas others coincided with the gradual tectonic uplift of Altos de Talinay be- evolved more recently in the Atacama Desert. Examples of some tween 5 and 2 million years ago, and produced a refuge that species with an old tropical origin are found both in the northern allowed the persistence of northern remnants of the subtropical (Myrcianthes coquimbensis), and southern (Pouteria splendens) forest. coasts of the Region; both of these species have large fleshy fruits, The humid conditions present during the glacial periods of the recalcitrant seeds and no current legitimate dispersers (Loayza Pleistocene allowed the persistence and some degree of connec- et al., 2014). tivity of the relict forest of Olivillo (Aextoxicon punctatum) along the Based on phylogenies of some genera of Asteraceae, the flora of north-central Chilean coast (Villagran et al., 2004). However, dur- the Atacama Desert appears to have multiple origins, and is ing interglacial periods (including the current one) the increase in phylogenetically related to species in central and southern Chile, aridity heightened the discontinuities of the relict forest. In this the Mediterranean Andes, Patagonia, and the Monte Province of regard, the expansion of the semi-arid scrub and restriction of relict Argentina's Chaco Region (Urtubey et al., 2010). Floristic in- forests to hilltops with permanent fogs would have severed the terchanges between the southern edge of the Atacama Desert and connectivity of this forest to the sclerophyllous forest of central central Chile were possible due to the lack of large biogeographic Chile (Troncoso et al., 1980; Villagran and Armesto, 1980; Villagran barriers (Luebert, 2011). Moreover, palynological data reveals that et al., 2004). This fragmentation process has resulted in genetic central Chile experienced dry periods during the Holocene, which differentiation among the forest remnants. For example, Jara- may have led to the southern expansion of lineages from the Ata- Arancio et al. (2012) found a high degree of leaf morphological cama Desert (Villagran and Varela, 1990; Villa-Martínez and and genetic divergence between Drimys winteri populations in Villagran, 1997). PNBFJ and other Chilean populations. Similarly, there is evidence of high genetic differentiation between A. punctatum populations, 3. Fog as a water source suggesting a long history of restricted genetic exchange (Núnez-~ Avila and Armesto, 2006). Expansion of the arid scrub during the Relict Olivillo forests have been recognized as “fog-forests” for interglacial periods coupled with isolation of relict forest on hill- well over a century (Philippi, 1884; Munoz~ and Pisano, 1947). tops can also explain the presence of other remnants of the pale- Kummerow (1962, 1966) showed that fog condensation could ocommunity in ravines and hilltops of Chile's north-central coast. greatly exceed the water contributed by rainfall (ca. 350 mm), For example, A. punctatum forest relicts are restricted to the hilltop reaching over 1000 mm annually. Moreover, fog intensity is high of Cerro Santa Ines (32100S; 71290O), located in the southern limit during spring and early summer, when water is mostly needed, and of the Coquimbo Region (Francois, 2004).