Soil macrofauna in areas with different ages after Pinus patula clearcutting

Univ. Sci. 23 (3): 383-417, 2018. doi: 10.11144/Javeriana.SC23-3.smia Bogotá original article Soil macrofauna in areas with different ages after Pinus patula clearcutting Esteban Tulande-M.1, *, José Ignacio Barrera-Cataño1, 2, Carlos Eduardo Alonso-Malaver1, 3, Carlos Morantes-Ariza2, Sofía Basto2 Edited by Juan Carlos Salcedo-Reyes () 1. Escuela de Restauración Ecológica, Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Carrera 7 No. 43-82, Bogotá, Colombia. 2. Unidad de Ecología y Sistemática (unesis), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Carrera 7 No. 43-82, Bogotá, Colombia. 3- Departamento de Estadística, Facultad de Ciencias, Universidad Nacional de Colombia, Carrera 30 No. 45-03, Bogotá, Colombia. * Received: 07-06-2017 Accepted: 26-09-2018 Published on line: 26-12-2018 Citation: Tulande-M E, Barrera-Cataño JI, Alonso-Malaver CE, Morantes-Ariza C, Basto S. Soil macrofauna in areas with different ages after Pinus patula clearcutting, Universitas Scientiarum, 23 (3): 383-417, 2018. doi: 10.11144/Javeriana.SC23-3.smia Funding: Corporación Autónoma Regional de Cundinamarca (CAR) and Pontificia Universidad Javeriana (PUJ) to J.I.B-C. and S.B. Electronic supplementary material: N.A. Abstract In Andean high montane areas, the establishment of exotic tree forests changes the soil dynamics and its biodiversity. Soil macrofauna act as indicators of ecosystem successional processes, and may have an important role in ecological restoration processes after clearcutting exotic tree plantations. The aim of the present study was to understand how soil macrofaunal assemblies change in areas with different ages post clearcutting of Pinus patula, and to identify the soil physico-chemical variables that better explain these variations. The macrofauna in a high montane forest was evaluated along with that of three areas with different ages post clearcutting: 0, 2.5, and 5 years after clearcutting (Yac). The effect of soil physico-chemical variables on macrofauna abundance was also evaluated. Macrofauna composition changed after clearcutting. Macrofauna abundance, richness, and diversity were lower in the 0 Yac area than in the other areas. Moreover, the macrofuna similarity to the reference forest did not increase with the years after clearcutting. This is due to the changes in soil characteristics, triggered by clearcutting. Slope, temperature, bulk density, real density, loam, pH, P, Na and K were the soil variales with a positive effect on the macrofauna abundance. These physico-chemical variables should be considered when designing restoration plans for Andean forest ecosystems. Moreover, Diplopoda, Coleoptera and Chilopoda might be useful to monitor and evaluate restoration processes after Pinus spp. clearcutting, because of their high abundance, diversity and relationship with environmental conditions. Keywords: Andes; tropical montane forest; restoration ecology; soil macrofauna. Introduction Tropical montane forests, specifically high Andean ones, entail one of the most important ecosystems on Earth due to their high biodiversity [1, 2] and their key role providing vital ecosystem services to human populations: Universitas Scientiarum, Journal of the Faculty of Sciences, Pontificia Universidad Javeriana, is licensed under the Creative Commons Attribution 4.0 International Public License 384 Macrofauna after Pinus sp. clearcutting water, food, and climate regulation. However, high montane forests are one of the most threatened ecosystems and, thus, are target of conservation and restoration efforts promoted in recent years [3-7]. The Andean region of Colombia is the most densely populated of the country. This has led to extensive transformations of its forests. In consequence, only 10 % of the original Andean forests are still conserved and less than 5 % of these are specifically high montane forests [2, 5, 8]. For over a century, Colombian high Andean forests have been transformed into exotic tree plantations. The exotic pine Pinus patula is one of the tree species most used for this purpose [4, 9, 10]. Compared to areas with semi-natural high montane forest vegetation, the soil environment in pine plantations experiences unique dynamics. Pine needles deposited on the soil are rich in lignin and take longer to degrade. This results in the accumulation of a layer of scarcely degraded organic matter (OM). This type of OM is characteristic of coniferous forests [11-14]. Moreover, litter produced by species of Andean forests has a high N and C content, thus its degradation and nutrient turnover rate is accelerated [15-18]. In addition, the low temperature and humidity of the Andean region decreases the speed of OM degradation in the surface horizon. This leads to accumulation of OM in the top soil [19-23]. OM is the basis and the main source of energy of the soil’s food chain [24-27], therefore, any change in OM forms will have strong effects on the entire soil biota, mainly on its macrofauna, because their digestive system lacks of lignolytic enzymes to process material with highly polymerized polysaccharides [28-32]. Edaphic macrofauna entail all soil invertebrates larger than 2 mm belonging to different taxonomic groups. Macrofauna are essential elements of the edaphic ecosystem because of their size, whereby they have a unique role in the ecosystem, specifically by regulating soil dynamics such as nutrient cycling and controlling pests and diseases [33-36]. Moreover, they have an indirect effect on OM mineralization and humification processes by enhancing functions of the edaphic meso and microfauna [37-39]. This link with ecosystem functioning makes them indicators of soil quality [40, 41], disturbance [24, 42, 43] and successional processes [44-46]. For these reasons, in the last decade, there has been a growing interest in studying their role in ecological restoration processes [38, 47-50]. In Colombia, studies have investigated the macrofauna composition of Andean forests, exotic tree species plantations, and agricultural lands, revealing a higher soil macrofauna diversity in Andean forests compared to both conifer plantations and agricultural areas [51-59]. However, there are no studies investigating macrofauna succession processes nor the relationships between Universitas Scientiarum Vol. 23 (3): 383-417 http://ciencias.javeriana.edu.co/investigacion/universitas-scientiarum 385 Tulande-M et al. macrofauna and physico-chemical variables in areas after clearcutting of P. patula. In this study we addressed the questions on how do soil macrofauna composition, structure and function vary among areas with different post clearcutting ages of Pinus patula, and which physico-chemical soil variables better explain the possible variation. To answer these questions, we evaluated the composition and structure of the edaphic macrofauna of three high montane successional areas and a high A (...truncated)