Geographical variation in the contribution of planted and natural pine forests to the conservation of bird diversity

Abstract

Aim Tree plantations can have beneficial or detrimental effects on regional biodiversity. Here, we focus on how the contribution of pine plantations to the maintenance of regional bird diversity varies geographically compared to natural pine forests, after controlling for the effects of other factors that are known to influence the regional richness of pine forest dwelling birds.Location Spain.Methods We combined large-scale datasets from diverse sources (i.e. the Spanish Breeding Bird Atlas, the Third Spanish Forest Inventory, land use and forest distribution maps) to analyse the geographical variation of the contribution of pine plantations in relation to their natural counterparts to the maintenance of the regional species richness of pine forest dwelling birds. To do so, we also controlled for the main environmental, land use and forest structure factors using GLM models.Results Differences in bird diversity among planted and natural pine forests varied along latitudinal and longitudinal gradients after accounting for altitude, climate, land uses and vegetation structure of pine forests. Planted pine forests in the north-west of the Iberian Peninsula have the lowest bird species richness as compared to natural pine forests, and that difference decreased following a north-west-south-east gradient. Differences also varied among pine species; they were larger for the species with a higher productive vocation (Pinus sylvestris, Pinus nigra and Pinus pinaster) and not significantly different from zero for species with low commercial interest and mainly used for the restoration of tree cover (i.e. Pinus halepensis).Main conclusions The potential of plantations or natural pine forests to enhance biodiversity is highly dependent on both the pine species and the geographical location. On this basis, we identify the geographical areas (and pine species) where a major naturalization effort of plantations would be needed to increase bird diversity.

Managing the Early Warning Systems of Invasive Species of Plants, Birds, and Mammals in Natural and Planted Pine Forests

“…We detected general patterns for pine forests. However, specific research is necessary among pine species and forest composition and structure [52,61] in order to make specific management recommendations according to forest characteristics. Estimating the benefits of integrating an invasive species early warning system in forest management is an issue that requires further study.…”

“…The sources and data used are diverse and were collected at different scales: (1) the geographic and orographic variables were calculated based on digital elevation models (25 × 25 m) and national topographical maps; (2) the variables related to climate were derived from the models defined by Gonzalo [50] in a 1-km 2 grid; (3) land use and coverage used the information available in the Spanish Forest Map (1:50,000); (4) landscape fragmentation index and the interface surface between wildland and urban land were calculated using the CORINE Land Cover cartography from 2012 (CLC12) (European Environment Agency); (5) the native species biodiversity indicator that expresses the number of pine forest dwelling birds was obtained from the Spanish Breeding Bird Atlas [51] and previous works of the authors on Spanish pine forests [48,52]; (6) biodiversity indicators of native plants, such as richness in the number of trees and shrubs in a territory, were calculated using the Third Spanish Forest Inventory (96,660 stands sampled at a 1-km resolution) [53]; (7) population density potential was calculated for 5 × 5-km grids [54]; (8) the density of roads and railways was estimated based on the Spanish Topographic Map (1:200,000); (9) density data on the number of forest fires and burned surface area were obtained from the Spanish Forest Fire Report Database of the Ministry of Agriculture and Fisheries, Food, and Environment (data from 1974 to 2008); finally, (10) historical and genetic data for classifying pine forest patches as either planted or natural were obtained based on Alía et al [40]. ArcGIS ® software (Esri Inc., Redlands, CA, USA) by Esri was used to process all the information and adapt it to the same 10 × 10-km UTM scale.…”

“…The analysis includes the interaction between the planted condition of native pines species and the location variable. This interaction is justified since plantations of the northwestern part of the Iberian peninsula (the purpose of which is more for production) and plantations of the southeastern part of the Iberian peninsula (which have a more restorative purpose) have different effects on the biodiversity associated with natural and planted pine forests [52]. The Hurdle model that is used ("pscl" library in R 3.3.1-software, [55,56]) has two components: a first component that models the absence and presence of invasive alien species (binomial with a logit link) and a second component that models the quantities truncated to the fact that the value of the richness of invasive alien species is positive (truncated poisson with a log link).…”

Mitigation strategies for conserving bird diversity under climate change scenarios in Europe: The role of forest naturalization

“…This result suggests that equilibrated proportions of natural and planted pine forests within currently dominant planted Pine spp. 10 x 10-km cells may increase the number of species of pine forest dwelling birds [ 17 , 24 ]. Such a result can arise if the list of species linked to plantations is different from the list of natural forests, so that mixes of managed and unmanaged habitat would maintain more species than pure habitat patches [ 44 , 45 ].…”

“…We specifically attempt to avoid any idealistic view of naturalization as a mitigation tool to prevent climate-driven biodiversity loss and the associated reduction in ecosystem services [ 15 ]. The relationships between naturalization and biodiversity are expected, in fact, to be highly variable due to the non-linear responses by species abundance and diversity to climate change [ 16 ] and management practices [ 17 ].…”