Use of Remote Sensing Techniques to Estimate Plant Diversity within Ecological Networks: A Worked Example

As there is an urgent need to protect rapidly declining global diversity, it is important to identify methods to quickly estimate the diversity and heterogeneity of a region and effectively implement monitoring and conservation plans. The combination of remotely sensed and field-collected data, under the paradigm of the Spectral Variation Hypothesis (SVH), represents one of the most promising approaches to boost large-scale and reliable biodiversity monitoring practices. Here, the potential of SVH to capture information on plant diversity at a fine scale in an ecological network (EN) embedded in a complex landscape has been tested using two new and promising methodological approaches: the first estimates α and β spectral diversity and the latter ecosystem spectral heterogeneity expressed as Rao’s Quadratic heterogeneity measure (Rao’s Q). Both approaches are available thanks to two brand-new R packages: “biodivMapR” and “rasterdiv”. Our aims were to investigate if spectral diversity and heterogeneity provide reliable information to assess and monitor over time floristic diversity maintained in an EN selected as an example and located in northeast Italy. We analyzed and compared spectral and taxonomic α and β diversities and spectral and landscape heterogeneity, based on field-based plant data collection and remotely sensed data from Sentinel-2A, using different statistical approaches. We observed a positive relationship between taxonomic and spectral diversity and also between spectral heterogeneity, landscape heterogeneity, and the amount of alien species in relation to the native ones, reaching a value of R2 = 0.36 and R2 = 0.43, respectively. Our results confirmed the effectiveness of estimating and mapping α and β spectral diversity and ecosystem spectral heterogeneity using remotely sensed images. Moreover, we highlighted that spectral diversity values become more effective to identify biodiversity-rich areas, representing the most important diversity hotspots to be preserved. Finally, the spectral heterogeneity index in anthropogenic landscapes could be a powerful method to identify those areas most at risk of biological invasion

Soil management shapes ecosystem service provision and trade-offs in agricultural landscapes

Agroecosystems are principally managed to maximize food provisioning even if they receive a large array of supporting and regulating ecosystem services (ESs). Hence, comprehensive studies investigating the effects of local management and landscape composition on the provision of and trade-offs between multiple ESs are urgently needed. We explored the effects of conservation tillage, nitrogen fertilization and landscape composition on six ESs (crop production, disease control, soil fertility, water quality regulation, weed and pest control) in winter cereals. Conservation tillage enhanced soil fertility and pest control, decreased water quality regulation and weed control, without affecting crop production and disease control. Fertilization only influenced crop production by increasing grain yield. Landscape intensification reduced the provision of disease and pest control. We also found tillage and landscape composition to interactively affect water quality regulation and weed control. Under N fertilization, conventional tillage resulted in more trade-offs between ESs than conservation tillage. Our results demonstrate that soil management and landscape composition affect the provision of several ESs and that soil management potentially shapes the trade-offs between them

Conservation tillage mitigates the negative effect of landscape simplification on biological control

Biological pest control is a key ecosystem service, and it depends on multiple factors acting from the local to the landscape scale. However, the effects of soil management on biological control and its potential interaction with landscape are still poorly understood. In a field exclusion experiment, we explored the relative effect of tillage system (conservation vs. conventional tillage) on aphid biological control in 15 pairs of winter cereal fields (barley and wheat) selected along a gradient of landscape complexity. We sampled the abundance of the main natural enemy guilds, and we evaluated their relative contribution to aphid predation and parasitism. Conservation tillage was found to support more abundant predator communities and higher aphid predation (16% higher than in the fields managed under conventional tillage). In particular, both the abundance and the aphid predation of vegetation- and ground-dwelling arthropods were increased under conservation tillage conditions. Conservation tillage also increased the parasitism rate of aphids. A high proportion of semi-natural habitats in the landscape enhanced both aphid parasitism and predation by vegetation-dwelling organisms but only in the fields managed under conventional tillage. The better local habitat quality provided by conservation tillage may compensate for a low-quality landscape. Synthesis and applications. Our study stresses the importance of considering both soil management and landscape composition when planning strategies to maximize biological control services in agro-ecosystems, highlighting the role played by conservation tillage in supporting natural enemy communities. In simple landscapes, the adoption of conservation tillage will locally improve biological control provided by both predators and parasitoids mitigating the negative effects of landscape simplification. Moreover, considering the small scale at which both predation and parasitism responded to landscape composition, a successful strategy to improve biological control would be to establish a fine mosaic of crop and non-crop areas such as hedgerows, tree lines and small semi-natural habitat patches

Governance of interdependent ecosystem services and common-pool resources

Environmental governance is recognized as a key issue in many natural and social sciences. It is highly relevant for ecosystem services and common-pool resources as well. Both fields overlap yet have typically been studied separately. Therefore, this study aimed a) to examine the emerging body of literature that incorporates concepts from both fields of research and considers governance challenges, and b) to identify policy tools and recommendations presented for addressing those challenges. The analysis of thirty-nine selected peer-review papers revealed the multiplicity of interacting governance challenges with three major categories: environmental, socioeconomic, and problems of governance itself. Governance is impeded by institutional mismatches, exclusion of local actors, corruption, and perverse policies. The proposed policy recommendations most often suggest changes in institutional arrangements and increasing scientific understanding. Meeting human needs, and increasing social equity and justice were recognized broadly as integral for improving governance, yet correlations among governance problems and solutions appear elusive. These findings extend theoretical reasoning, while carrying practical implications for policy, governance and environmental stewardship. The analysis implies that policies to improve human conditions will be key for improved environmental governance, but more research is needed to learn which types of policy recommendations prove successful given diverse local contexts

Cross-taxon congruence between predatory arthropods and plants across Mediterranean agricultural landscapes

Although arthropods are among the most diverse, abundant and ecologically important animals in terrestrial ecosystems, they are generally neglected in most biodiversity inventories due to their complex systematics and overwhelming diversity, coupled with the current decline in the number of taxonomists. For this reason, several surrogate groups for arthropod diversity have been proposed, with plants being identified as a good putative cross-taxon indicator. By sampling plants and three groups of ground-dwelling arthropods (rove beetles, ground beetles and spiders) in 300 sites across 15 landscapes including multiple semi-natural and agricultural habitats, we tested for habitat-dependence and scale-dependence in the cross-taxon congruence. Plant species richness was a poor predictor of the species richness of predatory arthropods. Among the predator groups, ground beetles appeared as the best potential surrogate for the other ground-dwelling predators. This is backed by the fact that ground beetles were extremely diverse and abundant in all habitats and are usually easier to identify than both rove beetles and spiders. Decreasing the scale at which the cross-taxon congruence was tested improved the strength of the cross-taxon congruence. Although plant species richness was not a suitable indicator for the diversity of predatory arthropods, vegetation structure played a significant role in influencing cross-taxon congruence in both natural and agricultural habitats. Our results highlight the need to explore the cross-taxon relationships at a fine habitat resolution scale, as strong correlations were obtained only by taking into account habitat identity

AGRICOLTURA CONSERVATIVA IN FRIULI VENEZIA GIULIA: UNA OPPORTUNITA' PER I SEMINATIVI

Principles and analysis of the perspectives for diffusion of conservation agriculture with reference to practical applications

Landscape and microhabitat features determine small mammal abundance in forest patches in agricultural landscapes

Intensification of agricultural landscapes represent a major threat for biodiversity conservation also affecting several ecosystem services. The natural and semi-natural remnants, available in the agricultural matrix, represent important sites for small mammals and rodents, which are fundamental for sustaining various ecosystem functions and trophic chains. We studied the populations of two small mammals (Apodemus agrarius, A. sylvaticus) to evaluate the effects of landscape and habitat features on species abundance along a gradient of agricultural landscape intensification. The study was performed in Friuli Venezia Giulia (north-eastern Italy) during 19 months, in 19 wood remnants. Species abundance was determined using Capture-Mark-Recapture (CMR) techniques. In the same plots, main ecological parameters of the habitat (at microhabitat and patch scale) and landscape were considered. Abundance of A. agrarius increased in landscapes with high extent of permanent crops (i.e., orchards and poplar plantations) and low content of undecomposed litter in the wood understory. Instead, A. sylvaticus, a more generalist species, showed an opposite, albeit less strong, relationship with the same variables. Both species were not affected by any landscape structural feature (e.g., patch shape, isolation). Our findings showed that microhabitat features and landscape composition rather than wood and landscape structure affect populations' abundance and species interaction. The opposite response of the two study species was probably because of their specific ecological requirements. In this light, conservation management of agricultural landscapes should consider the ecological needs of species at both landscape and habitat levels, by rebalancing composition patterns in the context of ecological intensification, and promoting a sustainable forest patch management

Multifunctional use of landscapes in protected areas

Multifunctionality is a very important concept for the landscape management in environmental conservation areas. In fact, these areas are characterised by natural values and also by (usually dominant) agricultural land uses that can support, or can be associated, with high biodiversity or with species and habitats of European wide interest. So, rural landscape within protected areas should support both economic and natural functions. The paper aims to explore the relationship between rural landscape multifunctionality and ecosystem service concepts and to analyse the usefulness of this relationship in planning and management of rural land. An approach is presented to measure agro-ecosystems services based on supporting of nutrient cycles and regulating soil quality, rather than on agricultural products. Intensity of agricultural land use, through the assessment of cultures, is valued and it is measured on the basis of parameters such as the physical alteration of the soil due to cultivation and the amount of nutrients (chemical fertilizer) provided. Moreover, high value habitats as natural meadows areas are identified and studied. The results obtained in terms of both sensitivity of habitats to agriculture and intensity of cultivation are useful in the process of identification of critical management areas, fundamental step to lead management measures