The surrounding landscape influences the diversity of leaf-litter ants in riparian cloud forest remnants

Abstract

Riparian vegetation is a distinctive and ecologically important element of landscapes worldwide. However, the relative influence of the surrounding landscape on the conservation of the biodiversity of riparian remnants in human-modified tropical landscapes is poorly understood. We studied the surrounding landscape to evaluate its influence on leaf-litter-ant alpha and beta diversity in riparian remnants in the tropical montane cloud forest region of central Veracruz, Mexico. Sampling was carried out in 12 sites with riparian vegetation during both rainy (2011) and dry (2012) seasons. Ten leaf-litter samples were collected along a 100-m transect per site and processed with Berlese-Tullgren funnels and Winkler sacks. Using remotely-sensed and ground-collected data, we characterized the landscape around each site according to nine land cover types and computed metrics of landscape composition and configuration. We collected a total of 8,684 ant individuals belonging to 53 species, 22 genera, 11 tribes, and 7 subfamilies. Species richness and the diversity of Shannon and Simpson increased significantly in remnants immersed in landscapes with a high percentage of riparian land cover and a low percentage of land covers with areas reforested with Pinus, cattle pastures, and human settlements and infrastructure. The composition of ant assemblages was a function of the percentage of riparian land cover in the landscape. This study found evidence that leaf-litter ants, a highly specialized guild of arthropods, are mainly impacted by landscape composition and the configuration of the focal remnant. Maintaining or improving the surrounding landscape quality of riparian vegetation remnants can stimulate the movement of biodiversity among forest and riparian remnants and foster the provision of ecosystem services by these ecosystems. Effective outcomes may be achieved by considering scientific knowledge during the early stages of riparian policy formulation, in addition to integrating riparian management strategies with broader environmental planning instruments.

Agricultural matrices affect ground ant assemblage composition inside forest fragments

“…Some species are very flexible and can survive in the homogeneous conditions provided in this agricultural matrix [ 11 ]. Other researchers have verified that habitat heterogeneity is a determinant factor of richness [ 19 , 63 ] and composition [ 17 , 63 ]of ant species. But, unlike the findings of these researchers, our findings indicate that habitat shapes the ant communities but does not influence species richness, in some locations.…”

“…We add adjacent vegetation type to Lawton's hypothesis [ 78 ] in which ant communities are shaped not only by vegetation structure where they are inserted but also by the surrounding vegetation, an issue that is supported by similar studies on ants in fragmented landscapes [ 17 , 19 ]. This would explain the divergence among the ant communities in different agricultural matrices and surrounding forest fragment, an important consideration for reconciling biodiversity conservation and agriculture throughout the landscape.…”

“…The nature of the surrounding agricultural matrices affects forest species dynamics [ 2 ] at local, landscape and regional scales [ 16 ]. Its degree and type of influence on arthropod assemblages can depend on the percentage of forest remaining in the landscape [ 17 ] and the remnant’s area, edge and shape [ 18 ]; conversely, assemblages in the matrix can be influenced by the distance of the matrix from the forest [ 19 ]. Agricultural land is inhospitable to most forest species [ 9 , 11 ] and such matrices exert pressure on forest fragments [ 20 , 21 ], working as a biodiversity filter, which affects the movement of species between and within fragments [ 9 ].…”

Impacts of Habitat Degradation on Tropical Montane Biodiversity and Ecosystem Services: A Systematic Map for Identifying Future Research Priorities

“…Although fragmentation is well-known for reducing gene flow, it has far-reaching consequences at all ecological levels, including ecosystem services. In general, fragmentation has a negative impact on communities; resulting in a decline in species richness (e.g., Borgella et al, 2001;Kumar and O'Donnell, 2007;Hundera et al, 2013;Mohandass et al, 2014;Rovero et al, 2014), and changes in species composition in response to fragmentation has also been consistently reported (e.g., Larrea and Werner, 2010;Mohandass et al, 2014;Rueda-Hernandez et al, 2015;García-Martínez et al, 2017;Herrera-Paniagua et al, 2017). However, some studies have highlighted that certain spatial characteristics such as fragment area and isolation have no effect on abundance, density or diversity (Muriel and Kattan, 2009;Ulrich et al, 2016).…”

¿Refleja Formicidae el impacto de la degradación de los bosques ribereños en la Amazonía Oriental?

“…Debido a que la familia Formicidae cumple un papel fundamental en estos ambientes (Bardgett et al, 2001;García-Martínez et al, 2017), refleja los cambios a nivel estructural y funcional del suelo (García-Martínez et al, 2015), es abundante (Pinzón et al, 2015) y son pocos los estudios realizados en bosques ribereños, el presente trabajo tiene como objetivos evidenciar el aporte referencial de Formicidae en estas zonas y establecer diferencias en su riqueza, frecuencia y composición a través del gradiente de sucesión forestal. Las hipótesis consideradas en este estudio fueron que (1) existe una relación positiva entre el gradiente de sucesión forestal y la riqueza y frecuencia de Formicidae; (2) las áreas de sucesión comparten mayor número de especies y se distancian de áreas de uso antrópico; (3) la riqueza y frecuencia de este grupo es afectada por la cobertura de dosel, el altura de los árboles y el periodo de recolecta.…”