Biodiversity and metacommunity structure of animals along altitudinal gradients in tropical montane forests

Abstract

Abstract:The study of altitudinal gradients has made enduring contributions to the theoretical and empirical bases of modern biology. Unfortunately, the persistence of these systems and the species that compose them is threatened by land-use change at lower altitudes and by climate change throughout the gradients, but especially at higher altitudes. In this review, we focus on two broad themes that are inspired by altitudinal variation in tropical montane regions: (1) dimensions of biodiversity and (2) metacommunity structure. Species richness generally decreased with increasing altitude, although not always in a linear fashion. Mid-altitudinal peaks in richness were less common than monotonic declines, and altitudinal increases in richness were restricted to amphibian faunas. Moreover, gradients of biodiversity differed among dimensions (taxonomic, phylogenetic and functional) as well as among faunas (bats, rodents, birds) in the tropical Andes, suggesting that species richness is not a good surrogate for dimensions that reflect differences in the function or evolutionary history of species. Tropical montane metacommunities evinced a variety of structures, including nested (bats), Clementsian (rodents, bats, gastropods), quasi-Clementsian (reptiles, amphibians, passerines) and quasi-Gleasonian (gastropods) patterns. Nonetheless, compositional changes were always associated with the ecotones between rain forest and cloud forest, regardless of fauna.

New mining concessions will severely decrease biodiversity and ecosystem services in Ecuador

“…Cotacachi is largely at high elevation (>2,500 m) at its southern end. The BPs discussed here extend protection into the critically endangered NW cloud forest zone and upper montane forests that occur between 900-2500 m. These are the habitats preferred by the most endangered species in our study, including the primates (Jack & Campos, 2012;Peck et al, 2010) cats (Zapata-Ríos & Araguillin, 2013), and bears (Castellanos, 2011), as well as the frogs (Arteaga et al, 2016;Tapia et al, 2017), birds (Jahn, 2008;Willig & Presley, 2016) and orchids (Endara et al 2009). We recommend that the entire Bosque Protector system be extended the same protections as the SNAP system, particularly with regards to prohibition of mining.…”

“…These persistently foggy and rainy forests are speciose with epiphytes, such as orchids and bromeliads (Gentry & Dodson, 1987;Kuper, Kreft, Nieder, Koster, & Barthlott, 2004). Several other taxa have higher diversity in the cloud forest zone relative to either higher or lower elevations, including: moths (Brehm et al, 2016), frogs (Willig & Presley, 2016), caddisflies (Blanca Ríos-Touma, Holzenthal, Huisman, Thomson, & Rázuri-Gonzales, 2017), and tree ferns (Ramirez-Barahona, Luna-Vega, & Tejero-Diez, 2011). Ecuador is crossed by two main mountain ranges, the Cordillera Occidental and the Cordillera Oriental, each with cloud forest zones that differ in floristic composition and that harbor specialized microhabitats with narrow endemic species and due to its latitude, Ecuador's vegetation has northern and southern elements (Jørgensen & Léon-Yánez, 1999).…”

Dimensions of passerine biodiversity along an elevational gradient: a nexus for historical biogeography and contemporary ecology

“…Major ecological theories for biodiversity patterns along elevational gradients are similar to those for latitudinal gradients (Willig and Presley 2016): species richness is generally thought to decline with increasing elevation for a number of reasons, including decreasing resource abundance and diversity (Jankowski et al 2013), and environmental factors that result in species filtering at higher elevations (e.g. lower temperatures and increased seasonality; Coyle et al 2014).…”

Subtle changes in elevation shift bat‐assemblage structure in Central Amazonia

“…Resource distributions are strongly related to topography. Regions with large elevational changes (>3000 m) have large soil, climate, and vegetation gradients, which create multiple habitat types that promote species turnover (McCain , Willig & Presley ). However, subtle changes in elevation (<100 m) may also affect species distributions (Menin et al .…”

“…Resource distributions are strongly related to topography. Regions with large elevational changes (>3000 m) have large soil, climate, and vegetation gradients, which create multiple habitat types that promote species turnover (McCain 2007, Willig & Presley 2016. However, subtle changes in elevation (<100 m) may also affect species distributions (Menin et al 2007, Fraga et al 2011, Cintra & Naka 2012, Baccaro et al 2013, Dias-Terceiro et al 2015 and may be correlated with water table depth, temperature, soil fertility and texture, which promote changes in plant species composition (Pansonato et al 2013, Schietti et al 2014.…”