Variability of Ant Community Composition in Cork Oak Woodlands Across the Mediterranean Region: Implications for Forest Management
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Research Article ii FF o o r r e e s s t t doi: 10.3832/ifor2321-010 Biogeosciences and Forestry vol. 10, pp. 707-714 Variability of ant community composition in cork oak woodlands across the Mediterranean region: implications for forest management Marcello Verdinelli (1), We evaluated the potential use of ants as a powerful tool for environmental Salah Eddine Bakkali Yakhlef (2), monitoring, together with the applicability of the functional group approach as Carlo Simone Cossu (1), an alternative method for studying ant communities in cork oak woodlands. (1) Variations in ant community composition, diversity and functional groups were Oriana Pilia , studied in two cork oak forested sites across the Mediterranean region. Ants (1) Roberto Mannu were sampled using pitfall traps placed along linear transects at 12 sites located in the main cork districts of Italy and Morocco (Gallura in Sardinia, and Maâmora, east of Rabat). A total of 13,501 specimens were collected, belong- ing to 38 species (five shared species). A distinct separation in the NMDS plots between Gallura and Maâmora ant assemblages was clearly visible. Ant species composition was widely different between the two districts and significant dif- ferences were detected within the Gallura district at the species level. Oppor- tunist species were well represented in Gallura (about 27% of average Bray- Curtis similarity) as well as cryptic species (over 23%). In the Maâmora forest, generalized Myrmicinae, hot climate specialists and opportunists contributed equally to the average similarity (together about 53%). Multi-scale ant diver- sity showed that the true turnover was higher in Gallura than in Maâmora. These findings support the idea that the functional group approach, rather than species diversity per se, could be considered as a valuable tool to detect the response of the ant community to environmental changes in Mediter- ranean cork oak woodlands. Using ants as bioindicators could help not only in detecting early warning signs of habitat disturbance, but also in defining a use- ful management strategy to increase the resilience of agroforestry systems under future global change scenarios. Keywords: Cork Oak, Forest Management, Ants, Bioindicators Introduction wood pastures in Europe. Cork oak wood- of cork oak landscapes, thus accelerating Cork oak (Quercus suber Linnaeus, 1753) is lands have historically been subjected to tree mortality and limiting the natural re- a typical evergreen species, which is found intense disturbances, with a greater threat generation. in mixed forests, woodlands and managed of deforestation in recent times (Aronson Playing a key role in biodiversity, with a agroforestry systems in the western Medi- et al. 2009). Inadequate management and variety of specific responses to environ- terranean region (Bugalho et al. 2011). Con- land overuse are the main triggers of sev- mental stressors, macroinvertebrates have sidered as biodiversity hotspots, cork oak eral dynamic interactions that compromise been extensively used as biological indica- land use systems cover nearly 2.5 million ha the ecology and conservation of cork oak tors in a vast range of habitats (Gerlach et in Europe and North Africa (Aronson et al. woodlands (Aronson et al. 2009, Bugalho al. 2013). The role of ants as environmental 2009). Cork oak agroforestry systems, et al. 2011). In the decades to come, the indicators is thus becoming more impor- commonly known as montados in Portugal, combined pressure of climatic change and tant in assessing the ecological health of dehesas in Spain and azaghar in parts of anthropogenic impacts will likely exacer- terrestrial ecosystems, mostly because of Morocco, are important managed ecosys- bate the effects of pests and pathogens, their high diversity and functional impor- tems, which represent the most extensive which in turn will increase the vulnerability tance (Andersen et al. 2002, Andersen & Majer 2004, Ellison 2012, Fisher et al. 2014). Ants are well represented in almost all ter- (1) Istituto per lo Studio degli Ecosistemi, CNR, Traversa La Crucca 3, 07100 Sassari restrial habitats because of a wide range of (Italy); (2) Division de l’Enseignement Supérieur et de la la Recherche et du Développement, thermal niches and their ability to cope in Direction de l’Enseignement, de la Formation et de la Recherche, Station D’bagh - Avenue varying environmental conditions. Most Hassan II, B.P. 607 Rabat (Morocco) studies focusing on the use of ants as bio- indicators have been conducted in Austra- @ Marcello Verdinelli ([email protected]) lia, and North and South America, whereas less attention has been devoted to under- Received: Dec 19, 2016 - Accepted: May 12, 2017 standing the anthropogenic impact on European ant communities (Castracani & Citation: Verdinelli M, Yakhlef SEB, Cossu CS, Pilia O, Mannu R (2017). Variability of ant Mori 2006, Ottonetti et al. 2006, Castracani community composition in cork oak woodlands across the Mediterranean region: implications et al. 2010, Azcarate & Peco 2012, Satta et for forest management. iForest 10: 707-714. – doi: 10.3832/ifor2321-010 [online 2017-07-27] al. 2012). The analysis of ant community structures in relation to habitat stress or Communicated by: Massimo Faccoli disturbance could be a valuable tool to detect early environmental changes in Me- © SISEF http://www.sisef.it/iforest/ 707 iForest 10: 707-714 Verdinelli M et al. - iForest 10: 707-714 y r diterranean habitats (Cammell et al. 1996, production, which is mainly located in rural (Nafaa 2002). t s Gómez et al. 2003, Castracani et al. 2010). marginal areas, is often considered as a The aim of our work was to compare the e r Species richness and other traditional di- secondary source of income. In parts of the ant assemblages between the cork oak o versity measures have been commonly Gallura district, there is a lack of natural woodlands of the two sites in Morocco and F used in several ecological studies concern- regeneration (Rossetti & Bagella 2014). Italy; to study how the diversity and faunal d n ing ants as model organisms (Castracani & Consequently, much effort and public composition varied at different spatial a Mori 2006, Graham et al. 2009). Recently, funds have been devoted to improving scales; and how the functional group s e there has been considerable interest in the woodland management practices. scheme could be adapted to Mediterra- c n use of a complementary approach based The Maâmora forest is considered to be nean ant assemblages. e i on functional groups to predict ant spatial the largest existing managed cork oak c s patterns in disturbed landscapes. This ap- woodland in the world, and represents a Materials and methods o proach has been used in Australia and paradigmatic example of a forest subject e g North America to reduce the complexity of to a dramatic human pressure due to over- Study areas and ant sampling o i ant taxonomy, and could also be exploited grazing and intensive cattle breeding The study was conducted in the main B as a reliable model for examining the ant (Aronson et al. 2009). The cork oak forest, cork oak districts of Gallura (Sardinia, Italy) – community structure and its relationship originally encompassing an area of 300,000 and Maâmora (Morocco). The Gallura cork t s with land use (Andersen 1995, Bestelmeyer ha (Boudy 1950), has now been reduced to oak district is located in a typical Mediter- e r & Wiens 1996, Andersen et al. 2002). Since less than 70,000 ha (Bugalho et al. 2011). As ranean landscape in the north of Sardinia, o F ant assemblages do not always follow a re- in most other western Mediterranean at an altitude of 50-600 m a.s.l. The climate i gular trend in response to environmental countries, there is almost no natural regen- is Mediterranean, with mild winters, hot stress and disturbance, there is an urgent eration in the entire Maâmora forest, and and dry summers; the rainfall distribution need for more studies focusing on species attempts have been made to reduce an- follows a typical Mediterranean pattern patterns, functional groups, diversity and thropogenic pressures through projects with a long dry season during the warmer dominance in order to provide a more that encourage sustainable forest manage- months and a greater concentration in late accurate predictive understanding of the ment (Besacier & Gallo Granizo 2014). Arti- autumn and early spring (average annual mechanisms that influence ant distribu- ficial reforestation (with eucalyptus, pine temperature 13.4 °C, average annual precip- tions in cork oak woodlands in warm-tem- and acacia) is largely practiced over the itation 785 mm). perate regions. entire area, although much effort has been In the Gallura area, soils are Eutric Lep- In this study, we compared ant communi- devoted to achieving a better cork oak pro- tosols (Costantini et al. 2012) according to ties from cork oak woodlands in the main tection and regeneration in recent decades the IUSS Working Group (2007). The under- cork districts of Italy (Gallura, Sardinia) and (Aronson et al. 2009). In addition to their story vegetation is mainly composed of Morocco (Maâmora forest), which repre- ecological role, cork oak woodlands are rockrose (Cistus monspeliensis Linnaeus, sent two striking examples of contrasting considered to be very important multipur- 1753 and Cistus salvifolius Linnaeus, 1753), forest-management models. pose systems in Morocco due to the wide broom [Calicotome spinosa (Linnaeus, 1753) The Gallura cork oak district, with