Latitudinal patterns and regionalization of plant diversity along a 4270‐km gradient in continental Chile

Abstract

According to the global latitudinal diversity gradient, a decrease in animal and plant species richness exists from the tropics towards higher latitudes. The aim of this study was to describe the latitudinal distribution patterns of Chilean continental flora and delineate biogeographic regions along a 4270-km north-south gradient. We reviewed plant lists for each of the 39 parallels of continental Chile to build a database of the geographical distribution of vascular plant species comprising 184 families, 957 genera and 3787 species, which corresponded to 100%, 94.9% and 74.2% of the richness previously defined for Chile, respectively. Using this latitudinal presence-absence species matrix, we identified areas with high plant richness and endemism and performed a Cluster analysis using Jaccard index to delineate biogeographic regions. This study found that richness at family, genus and species levels follow a unimodal 4270-km latitudinal distribution curve, with a concentration of richness in central Chile (31-42°S). The 37th parallel south (central Chile) presented the highest richness for all taxonomic levels and in specific zones the endemism (22-37°S) was especially high.This unimodal pattern contrasts the global latitudinal diversity gradient shown by other studies in the Northern hemisphere. Seven floristic regions were identified in this latitudinal gradient: tropical (18-22°S), north Mediterranean (23-28°S), central Mediterranean (29-32°S), south Mediterranean (33-37°S), north temperate (38-42°S), south temperate (43-52°S) and Austral (53-56°S). This regionalization coincides with previous bioclimatic classifications and illustrates the high heterogeneity of the biodiversity in Chile and the need for a reconsideration of governmental conservation strategies to protect this diversity throughout Chile.

Forest Typification to Characterize the Structure and Composition of Old-growth Evergreen Forests on Chiloe Island, North Patagonia (Chile)

“…This study provides evidence to indicate that the latitudinal ecotone between Valdivian and North-Patagonian forests within the Evergreen forest type occurs around the center of Chiloé (43° S), confirming the limit suggested by other authors between these two physiographic regions [15,32]. Furthermore, the limit proposed by the present study coincides with the division between the North and South temperate biogeographic region defined between parallels 42° and 43° S on the basis of 74% of the vascular species of Chile [33].…”

The orchids of Torres del Paine Biosphere Reserve: The need for species monitoring and ecotourism planning for biodiversity conservation

“…These findings put this area as one of the most diverse for this taxonomical group, as it contains about 35% of the orchids described for the Chilean Temperate-Austral floristic regions (sensu Bannister et al 2012) and 75% of the orchids recorded in the Magallanes Region (Henríquez et al 1995, Domínguez 2004, Novoa et al 2006. The high proportion of orchids occurring in Torres del Paine Biosphere Reserve address two issues which would be able to implement here for conservation purposes: first, the need of develop species taxonomic inventories for biodiversity monitoring (Noss 1990, Cameron 2010) and the potential of ecotourism planning to increase biodiversity valuation.…”

“…(Paine Grande), while the Grey glacier represents the south end of the Southern Patagonian Ice Field, the second largest extra polar extent of ice. Climatologically the area belongs to the humid-supratemperate belt (Amigo & Ramírez 1998) of the Temperat-Austral floristic transition (Bannister et al 2012), with average temperatures of 10.8°C in austral summer (January) and 2°C in the winter season (July). Although climate data are available from just one meteorological station located at the park administration (CONAF 2007), a drastic environmental gradient in northwest-southeast direction can be distinguished from the colder and humid areas near the Grey glacier to the warmer and dryer areas Sarmiento Lake.…”

The Importance of Microtopography and Nurse Canopy for Successful Restoration Planting of the Slow-Growing Conifer Pilgerodendron uviferum

“…Field sites were located in the disturbed forests around Lake Chaiguata. Southern Chiloé has a cool-temperate climate with strong oceanic influence and a mean annual temperature of 10 °C, belonging to the south temperate biogeographic region of Chile [23,24]. Annual precipitation is high, reaching up to 6000 mm in some places [25], and the altitudes range between 150 and 280 m a.s.l.…”