Description: Traditional management of montado ( dehesa ) is an example of integration of sustainable land-use and biodiversity conservation. The whole system sustainability is currently threatened by the intensification of soil tilling to control shrub invasion and promote pastureland, the absence of tree natural regeneration being one of the most outstanding threats. A study to assess effects of management on tree regeneration at early stages was developed in a cork oak montado grazed by cattle, in southern Portugal. We specifically compared the effects of harrowing every 3–4 years with those of shrub clearing with a shredder every 5–7 years. We hypothesized that extending shrub maintenance may facilitate cork oak regeneration at early stages in grazed montado . Fenced cork oak paddocks under the same management system for at least the last 40 years were surveyed for cork oak seedling, juvenile and sapling density; shrub cover percentage was also estimated. Recruitment bottleneck was observed after the seedling stage under harrowing, while in shredded areas all stages were well represented and often associated with shrub patches. Overall, the highest cork oak recruitment occurred at intermediate shrub cover (40–60 %). By maintaining shrub patches and their protective effect against direct radiation and grazing impact, while preventing shrub encroachment, shredding every 7 years seems to create an important temporal window for effective oak regeneration. This management practice might thus be suitable to favour successful tree regeneration in grazed cork oak montado , assuring the persistence of this system.

Description: In extensive low input farming and in agroforestry systems, the importance for biodiversity of managed productive fields with respect to unmanaged marginal habitats that occupy a low proportion of farm surface, is still poorly understood, contrasting with the well-known key importance of marginal habitats in intensive systems. We analyzed the importance of open and wood pastures and marginal habitats for species richness of Iberian dehesas in Central-Western Spain. We sampled 155 plots classified into 9 general habitat categories: wood pastures (n = 41 plots); open pastures dominated by annual plants (n = 11), by perennial plants (n = 15) and co-dominated by annuals and perennial plants (n = 16); shrublands (n = 19); agricultural crops (n = 12); herbaceous strips (n = 10); woody strips (n = 11); and water bodies (n = 10). In each plot we measured the abundance and species richness of four taxonomic groups: vascular plants, bees, spiders, and earthworms. We detected 431 plant species (37 ± 2.5 CI 95 in 100 m 2 on average), 60 bee species (3.1 ± 1.1 in 600 m 2 ), 128 spider species (7.4 ± 1.2 in 1.5 m 2 ) and 18 earthworm species (2.5 ± 1.0 in 0.27 m 2 ) in 145 sampling plots. Wood pastures supported fewer species of spiders and earthworms at the plot level, but more plants and earthworm species at the landscape level than open pastures. The low proportion of shared species among habitats and among plots within each habitat type, and the high proportion of species found in unique plots or habitats indicated that every habitat contributes to farm biodiversity. Overall, our extensive survey confirms the hypothesis that the high diversity of dehesas depends on the coexistence within farms of a wide mosaic of habitats, including marginal habitats, which seemed to harbor a disproportionately high number of species as compared to their small extent. Results support policy measures for the maintenance of farm keystone structures such as linear features, small wood/shrub patches and ponds, and reveal that these measures should not be exclusively applied to more intensive farming systems.

Description: Dendrometric parameters such as tree DBH, height, crown diameter and size characteristics of leaves and fruit production collected from Vitellaria paradoxa subsp. growing in three land use types in Pendjari Biosphere Reserve (PBR) were analyzed. A total of 36 circular plots of 15 m diameter were randomly set in the three main land use sites of the PBR. Thus, Shea butter production was estimated from 90 trees (30 trees in each site) selected randomly. Our results revealed a significant difference in trees traits which increase from the park and hunting zone to the farmlands. The highest production of the selected Shea trees was reported from the farmland. Thus, there is high variability between leaf sizes of trees within the sites while for the fruits the greatest variability is between fruits from same tree. The findings of this study showed that the morphological traits and the production of Shea butter trees could be affected by land use systems.

Description: The importance of tropical timber is increasing worldwide. However, the timber supply of tropical forests has been greatly impacted by growing deforestation associated with complex and restrictive timber harvest laws. In Central America, as well as in other developing regions, reforestation programs have often fallen short of expectations. In these cases, agroforestry proves to be a useful strategy for providing tropical timber supplies for smallholder farmers, rural development and environmental services. Timber yields and their potential revenues in four types of agroforestry systems (silvopastoral, coffee, cocoa and living fences) were researched in Nicaragua and Honduras. The results suggest that smallholder timber production in agroforestry systems is a profitable activity despite lower market prices than commanded by timber from forests. The net value from timber sales represents 11–49 % of the total revenue from agroforestry systems. However, this amount could be 58 % higher if farmers were able to improve management practices. Encouraging the knowledge and adoption of silvicultural practices in agroforestry systems is important to increasing timber revenues among smallholder farmers in Central America.

Description: The introduction of trees in cropland may be a way to improve the mineral nitrogen (N) use efficiency since tree roots can intercept N leached below the crop rooting zone and recycle it as organic N. The aim of this study was to determine soil mineral N (SMN) and total N (STN) contents after 14 years of hybrid walnut tree growth in an agroforestry system. Soil cores were collected and analyses in mid-autumn 2009, in intercropped agroforestry (AF), pure tree (FC) and sole crop control (CC) plots. The SMN was significantly reduced in AF compared to CC (64, 58 and 51 % of reduction at 0.2, 1 and 2 m depth respectively). In the top 1 m of soil, the stock of SMN was 77.7 kg N ha −1 in CC versus 32.8 kg N ha −1 in AF. Trees in AF developed deeper fine roots than in FC, likely involved in the reduction of SMN when compared to CC. Despite this quantitative reduction, trees also progressively modified the form of mineral N in soil by decreasing the percentage of nitrate (NO 3 − ) in SMN, particularly in FC compared to CC, while AF was intermediate. The STN was not significantly different between AF and CC; but was higher in FC in the top soil, probably due to weeds and superficial tree root biomasses. Our results suggest that the introduction of hybrid walnut trees into cropland may be an efficient practice to reduce the potentially leachable N by winter rainfall.

Description: Assessing the socio-economic sustainability of small scale forest plantations provides the basis for monitoring compliance with sustainable forest management principles and prescription of appropriate interventions. Considering that state forest plantations in South Africa have been scheduled for transfer to community-based entities, determination of the potential of alternative forest management types is vital. This study therefore assessed the socio-economic sustainability of current forest management strategies in state forest plantations at Gaba and Rossbach in Limpopo Province of South Africa. It also determined the potential of alternative forest management regimes using perceptions of local communities. Summated rating scales principles were applied by using likert scaling to acquire the perceptions of local communities through scoring of indicators and verifiers. While the local community for Rossbach forest plantation was content with all indicators of socio-economic sustainability, the local community for Gaba was discontent with provision of products and the forest plantation’s contribution to their livelihoods. Both communities perceived joint forest management to be the optimal forest management regime across all indicators while expressing total lack of confidence in managing the forest plantations communally. Optimal socio-economic sustainability in the post-transfers era can be achieved through joint decision-making and formalized sharing of responsibilities and benefits between the communities and government.

Description: Although tree-based farming systems are often assumed to be “resilient” or “climate-smart” options, adoption is limited. It could be that the sensitivity of individual tree species to extreme weather events is poorly documented or new systems include unfamiliar species and technologies. This paper reports on initial results of an evaluation of farmers’ experiences with trees and crops for responding to major climatic exposures in 21 villages in northern and north-central Viet Nam. Our study assessed the suitability and roles of trees by analyzing data gathered through focus group discussions, workshops and a survey of 661 households. The results showed that a majority of households were exposed annually to what they perceived as natural hazards. Experiences with using trees for coping and adaptation depended on household income status, awareness and policies. In particular, farms with trees had shorter recovery time after most types of natural disasters, except for cold spells, demonstrating economic and environmental buffers. Many leaders were unfamiliar with agroforestry and mainly looking for economies of scale, hence oriented to land use rather than landscape planning. This indicates disconnects between farmers’ needs and policymakers’ priorities with respect to climate change adaptation strategies. Existing agroforestry systems reflected a transition from indigenous or current farming systems via changing to either new species or technologies rather than changing both at the same time. Gaps in current adaptation strategies and key areas for policy and research interventions are finally discussed.

Description: Eucalyptus is abundant in Rwanda, mainly planted in short rotation woodlots, scattered in small clusters over the hilly landscape. A study was done in Butare and Busoro catchments, southern Rwanda from May to November 2007 to estimated water use of eucalypts in representative catchments in Rwanda, establishing a monthly water balance. We compared eucalypt water use to water use of other key crops in the study area and to that of eucalypts elsewhere. The woodlots had small coppice shoots ranging from 2 to 36 cm breast height diameter and potential tree transpiration recorded was 3 mm d −1 . The annual potential tree transpiration was 10 % below annual precipitation. Dry month water deficit observed could be covered by reductions in leaf area, stomatal closure and changes in soil water storage. A sensitivity analysis showed that 50 % leaf area reduction corresponded to potential tree transpiration decline of 32.8 mm. The deficit may not impact tree growth negatively since dry seasons are usually not active for tree growth. The moderate eucalypt water use rate observed in this study may be a function of trees’ small size and low tree stocking since such woodlots had less potential transpiration. The observed eucalypt water use rate is smaller than the range reported for eucalypts in Africa and was also smaller than that of key annual crops in the study area. Managing woodlots as short rotations and increasing initial tree spacing may contribute to resolving issues related to catchment hydrology associated with eucalypt plantations.

Description: A growing number of studies argue that forest transition should be enhanced by policymakers given its potential benefits, for instance in slowing climate change through carbon sequestration. Yet the effects of forest transition in landscape heterogeneity and biodiversity remain poorly understood. In this paper we explore the relationships between the forest transition and the landscape changes occurred in a Mediterranean mountain area. Historical land-use maps were built from cadastral cartography (1854; 1956; 2012). Metrics on land-cover change, landscape structure, and landscape functioning were calculated. Multiyear data on butterfly assemblages from two transects (1994–2012) was used as indicator of land-use change effects on biodiversity. Results show a forest expansion process in former cereal fields, vineyards and pasturelands along with rural out-migration and land abandonment. Such forest transition involved large changes in landscape structure and functioning. As peasant management of integrated agrosilvopastoral systems disappeared, landscape became less diverse. Even if forest area is now larger than in mid-nineteenth century, ecological connectivity among woodland did not substantially improve. Instead, ecological connectivity across open habitats has greatly decreased as cereal fields, vineyards, meadows and pasturelands have almost disappeared. Butterfly assemblages under changing land-uses highlights the importance of agro-forest mosaics not only for these species but for biodiversity at large in the last decades. Our work emphasizes that conservation of landscapes with a long history of human use needs to take into account the role of humans in shaping ecological features and biodiversity. Hence the suitability of forest transitions should be critically examined in relation to context and policy objectives.

Description: Increases in the deposition of nitrogen affect biodiversity and the composition of natural vegetation. A significant amount of this nitrogen may originate not only from intensive agricultural and livestock farming, but also from wild ungulates whose abundance and area of distribution are currently increasing in the Iberian Peninsula. In this study we have estimated the abundance of two species of wild ungulates (red deer and wild boar) and the amount of nitrogen contained in their droppings and in the grass. We have also recorded the herbaceous community. The results show that the density of these ungulates is positively correlated to an increase in the grass nitrogen, which adversely affects the percentage of leguminosae in pastures. These results suggest that high densities of ungulates may be affecting plant communities by increasing the amount of nitrogen as a result the deposition of droppings. The current system of big game management should therefore be reviewed to make it compatible with the conservation of plant communities and small herbivore species that may be negatively affected by changes in pasture quality and quantity.