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Extensive conversion of terrestrial habitats to agriculture and widespread application of agro-chemicals have transformed ecosystems worldwide, threatening biodiversity, public health, and the ecosystem services on which food production relies. Conservation biological control is an approach to enhancing pest control ecosystem services by conserving and supporting natural enemies of agricultural pests. A clearer understanding of how pest management practices and plant diversity at different scales impact pest control ecosystem services may reduce reliance on chemical pesticides, conserve biodiversity, and enable the transition to more sustainable food production. Data was collected on organically managed strawberry (Fragaria × ananassa) fields in California’s Central Coast. Focal organisms were the lygus bug (Lygus spp., primarily Lygus hesperus), a major strawberry pest, and its suite of arthropod natural enemies. Study sites were selected along orthogonal gradients of landscape composition and local diversification practices. The effects of two pest management practices (insecticide application and tractor vacuum) were also investigated. At each site, arthropod communities were sampled using a hand-held vacuum, sentinel prey experiments were performed to estimate pest control levels (Chapter 1), and crops were surveyed for lygus bug damage (Chapter 2). Piecewise structural equation modeling (PSEM) was used to test causal pathways among landscape and local-scale variables, arthropod communities, pest control levels, and crop damage. Chapter 3 reports a field-scale study that employed novel bi-directional traps to detect spatial and temporal patterns of arthropod movement between crop and non-crop vegetation. The PSEM results provide evidence that landscape and local effects on pest control levels and crop damage are largely indirect and mediated through direct effects on arthropod communities. At the landscape scale, higher proportions of woods increased natural enemy abundance, which in turn increased pest control levels and decreased crop damage. Higher grassland proportions directly increased crop damage. Local diversification practices increased natural enemy diversity, which increased pest control levels. Both insecticides and tractor vacuuming were indirectly detrimental to pest control levels through their negative effects on natural enemy abundance. While insecticides also decreased pest abundance, vacuuming did not. The bi-directional movement study corroborated Chapter 1 and 2 results by showing that lygus bugs moved from weedy patches into crop fields more than they did from woody patches, and that natural enemies including spiders and wasps tended to do the opposite, moving more from woods into crops than they did from weeds. The spatial and temporal patterns displayed in the sentinel data, arthropod abundance, and crop damage data provide evidence for the hypothesis that crop damage is determined by pest abundance subject to natural enemy activity, and that natural enemies play a pivotal role in limiting crop damage. The evidence of causal pathways among plant diversity, arthropod communities, and pest control services, in combination with the spatial and temporal patterns detected by bi-directional trapping, can help growers and regional planners develop specific and effective strategies for enhancing pest control services, reducing reliance on insecticides and tractor vacuums, and promoting biodiversity.

Made available in DSpace on 2020-12-12T02:42:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Protecting riparian vegetation around streams is vital in reducing the detrimental effects of environmental change on freshwater ecosystems and in maintaining aquatic biodiversity. Thus, identifying ecological thresholds is useful for defining regulatory limits and for guiding the management of riparian zones towards the conservation of freshwater biota. Using nationwide data on fish and invertebrates occurring in small Brazilian streams, we estimated thresholds of native vegetation loss in which there are abrupt changes in the occurrence and abundance of freshwater bioindicators and tested whether there are congruent responses among different biomes, biological groups and riparian buffer sizes. Mean thresholds of native vegetation cover loss varied widely among biomes, buffer sizes and biological groups: ranging from 0.5% to 77.4% for fish, from 2.9% to 37.0% for aquatic invertebrates and from 3.8% to 43.2% for a subset of aquatic invertebrates. Confidence intervals for thresholds were wide, but the minimum values of these intervals were lower for the smaller riparian buffers (50 and 100 m) than larger ones (200 and 500 m), indicating that land use should be kept away from the streams. Also, thresholds occurred at a lower percentage of riparian vegetation loss in the smaller buffers, and were critically lower for invertebrates: reducing only 6.5% of native vegetation cover within a 50-m riparian buffer is enough to cross thresholds for invertebrates. Synthesis and applications. The high variability in biodiversity responses to loss of native riparian vegetation suggests caution in the use of a single riparian width for conservation actions or policy definitions nationwide. The most sensitive bioindicators can be used as early warning signals of abrupt changes in freshwater biodiversity. In practice, maintaining at least 50-m wide riparian reserves on each side of streams would be more effective to protect freshwater biodiversity in Brazil. However, incentives and conservation strategies to protect even wider riparian reserves (~100 m) and also taking into consideration the regional context will promote a greater benefit. This information should be used to set conservation goals and to create complementary mechanisms and policies to protect wider riparian reserves than those currently required by the federal law. Departamento de Ecologia Universidade Federal de Goiás (UFG) Instituto de Biociências Universidade Estadual Paulista (UNESP) Instituto Nacional de Pesquisas da Amazônia (INPA) Departamento de Biodiversidade Universidade Federal do Paraná (UFPR) Programa de Pós-Graduação em Tecnologias para o Desenvolvimento Sustentável Universidade Federal de São João Del Rei (UFSJ) Instituto Amazônico de Agriculturas Familiares Universidade Federal do Pará (UFPA) Laboratório de Hidrologia Florestal Escola Superior de Agricultura Luiz de Queiroz Universidade de São Paulo (USP) Instituto de Ciências Biológicas Universidade Federal do Pará (UFPA) Programa de Pós-Graduação em Biologia UNISINOS Departamento de Genética Ecologia e Evolução Instituto de Ciências Biológicas Universidade Federal de Minas Gerais (UFMG) Instituto de Geociências Departamento de Geografia Universidade Federal de Minas Gerais (UFMG) Laboratório de Ecologia e Conservação de Ecossistemas Aquáticos Universidade Federal de Mato Grosso (UFMT) Centro de Engenharias e Ciências Exatas Universidade Estadual do Oeste do Paraná (UNIOESTE) Laboratório de Sistemática e Ecologia de Insetos Departamento de Ciências Agrárias e Biológicas Universidade Federal do Espírito Santo (UFES) Campus de Ciências Exatas e Tecnológicas Universidade Estadual de Goiás (UEG) Departamento de Ecologia Universidade Federal do Rio Grande do Sul (UFRGS) Laboratório de Organismos Aquáticos (LOA) Departamento de Ciências Biológicas Universidade Estadual de Santa Cruz (UESC) Programa de Pós-Graduação em Ecologia e Conservação Universidade Federal do Mato Grosso do Sul (UFMS) Departamento de Entomologia Museu de Entomologia Universidade Federal de Viçosa (UFV) Instituto de Biociências Letras e Ciências Exatas Universidade Estadual Paulista (UNESP) Laboratório de Ecologia e Conservação Departamento de Engenharia Ambiental Universidade Federal do Paraná (UFPR) Programa de Pós Graduação em Biodiversidade (PPGBC) Universidade Federal do Pará (UFPA) Laboratório de Inteligência Artificial Eletrônica de Potência e Sistemas Digitais Universidade Federal de Mato Grosso do Sul (UFMS) Centro Universitário FG (UNIFG) Instituto Federal de Educação Ciencia e Tecnologia do Sul de Minas Gerais (IFSULDEMINAS) Universidade Federal de Alfenas (UNIFAL) Departamento de Biologia Universidade Federal de Lavras (UFLA) Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais (PEA) Universidade Estadual de Maringá (UEM) Instituto de Ciências e Tecnologia das Águas Universidade Federal do Oeste do Pará (UFOPA) Museu de História Natural Capão da Imbuia (MHNCI) Instituto Nacional de Pesquisa do Pantanal (INPP) Campus Avançado do Museu Paraense Emílio Goeldi (MPEG) Laboratório de Ecologia Centro de Estudos em Recursos Naturais (CERNA) Universidade Estadual de Mato Grosso do Sul (UEMS) Centre for Tropical Biodiversity and Climate Change and Centre for Tropical Environmental and Sustainability Studies College of Marine & Environmental Sciences James Cook University Instituto de Biociências Universidade Estadual Paulista (UNESP) Instituto de Biociências Letras e Ciências Exatas Universidade Estadual Paulista (UNESP) CNPq: 465610/2014-5

There is limited data on Sulphur (S) contents in arable soils for appropriate fertilizer recommendations in Ghana. Five study areas in a reconnaissance survey (RS), followed by an in-depth study of two areas comprising farms of different durations of cultivation, were investigated for the current total S and sulphate contents. Basic soil properties were measured using standard laboratory procedures. Total S and sulphate contents were determined using LECO instrument dry combustion and HPLC, respectively. The results showed wide variations in total S contents from 31 to 603 mg kg−1 in the Guinea Savannah (GS) zone. The mean trend was Forest > Forest-Transition (F-S) > north Guinea Savannah (nGS) > Deciduous Forest (DF) > south Guinea Savannah (sGS) in the RS sites, with a similar trend in the main study sites. Sulphate contents ranged from 5 to 25 mg kg−1, constituting 0.8 to 37% of the total S. The mean percent trend was sGS = DF > Forest > nGS > F-S. Soil organic carbon (SOC) was the major predictor of total S along with pedogenic minerals. Total S and crystalline pedogenic minerals predicted the sulphate contents. The results highlight the need for ecologically-based S fertilizer programmes to boost crop yields.

Agricultural expansion into natural habitats causes soil fertility decline after a period of cultivation. This study investigated changes in soil exchange properties in different farm types at Dompem and Adansam in the Forest and Forest–Savannah transition zones of Ghana as influenced by the duration of cultivation. Sixty farms were selected for soil sampling through a reconnaissance survey. The soils were subjected to physicochemical analysis. The results showed that the Dompem soils were loamic, had more amorphous Fe and Al oxides, were strongly acidic and had low contents of exchangeable acidity, a low sum of exchangeable bases (SEB), low effective cation exchangeable capacities (ECECs) and low available P. Conversely, the Adansam soils were arenic, slightly acidic and had relatively higher SEBs and ECECs. Interestingly, soil organic carbon (SOC) in the Dompem soils declined by >10% in relation to the duration of cultivation and showed rapid reductions within three years. Correspondingly, soil bulk density, CEC and SEB declined. In Adansam soils, only δpH declined in relation to the duration of cultivation. Soil organic carbon accounted for >50% of the ECEC and 49% of the SEB in Dompem soils but 36% of δpH in the Adansam soils. In conclusion, agricultural expansion, manifested in the duration of cultivation, mainly influenced soil charge properties through SOC decline.

Central Chile experienced a very extended and devastating fire season during 2016–17. After 3 years, here we present the results of an analysis of behavior of the wildfires occurred in that season. We used a modeling approach to estimate the physical parameters of fire behavior: speed of linear spread, front-line intensity and flame length; as well as qualified fire severity, and the potential danger of recurrent fires. We selected eight study areas in four regions of Central Chile, under sclerophyllous forest and shrublands with variable composition. To run the model, we gathered data on vegetation structure and composition, and physical information. The values of the physical parameters were in a comparable range in the eight studied areas, with two of these areas showing maximum values. This could result from differences in vegetation. We detected rapid regrowth post-fire, despite the high levels of fire intensity and damage, ascribed to a high availability of very dry fine biomass. Given the predictions of increased drought, we should expect recurrence of wildfires. Based on our results, we anticipate fires of high severity and damage, with emphasis in areas with very high increase of dry biomass. We suggest restoration programs, with frequent monitoring of passive restoration practices, resorting to more active physical support in areas more severely affected.

Wood-pastures are grazed systems, widespread across Europe, where natural and economic values often co-exist. Social and economic changes in Europe generate both threats and opportunities to these systems, calling for new or improved management strategies. We studied the potential of increasing the biodiversity of wood-pastures through the promotion of small-scale habitat diversification. More specifically, we evaluated the impact of protecting very small shrubby patches within large Mediterranean wood-pastures. We sampled species assemblages of plants, lichens and coleopterans in 13 small patches (252–3000 m2) with a well developed shrub layer, and 11 plots in the adjacent matrix of virtually shrub free wood-pasture. Despite their very small size, patches had clearly distinct assemblages of all the studied taxa and their presence greatly enhanced the species richness of the studied wood-pasture landscapes. The presence of shrubby patches increased species richness in wood-pastures by 42% for plants, 27% for lichens and 29% for coleopterans (average over two study areas), a very substantial gain considering that patches covered less than 0.5% of the studied wood-pastures. Our results indicate that the protection and promotion of even small shrubby patches is a promising low-cost nature-based strategy to increase the biodiversity value of wood-pasture landscapes, without substantially affecting the economic value of this silvopastoral system, which is an old and important part of the natural and cultural heritage of Europe., doctoral and post-doctoral grants: (PD/BD/106044/2015), (SFRH/BPD/88056/2012), (SFRH/BPD/118635/2016), and (SFRH/BPD/101983/2014).

Street trees are public resources planted in a municipality’s right‐of‐way and are a considerable component of urban forests throughout the world. Street trees provide numerous benefits to people. However, many metropolitan areas have a poor understanding of the value of street trees to wildlife, which presents a gap in our knowledge of conservation in urban ecosystems. Greater Los Angeles (LA) is a global city harboring one of the most diverse and extensive urban forests on the planet. The vast majority of the urban forest is nonnative in geographic origin, planted throughout LA following the influx of irrigated water in the early 1900s. In addition to its extensive urban forest, LA is home to a high diversity of birds, which utilize the metropolis throughout the annual cycle. The cover of the urban forest, and likely street trees, varies dramatically across a socioeconomic gradient. However, it is unknown how this variability influences avian communities. To understand the importance of street trees to urban avifauna, we documented foraging behavior by birds on native and nonnative street trees across a socioeconomic gradient throughout LA. Affluent communities harbored a unique composition of street trees, including denser and larger trees than lower‐income communities, which in turn, attracted nearly five times the density of feeding birds. Foraging birds strongly preferred two native street‐tree species as feeding substrates, the coast live oak (Quercus agrifolia) and the California sycamore (Platanus racemosa), and a handful of nonnative tree species, including the Chinese elm (Ulmus parvifolia), the carrotwood (Cupaniopsis anacardioides), and the southern live oak (Quercus virginiana), in greater proportion than their availability throughout the cityscape (two to three times their availability). Eighty‐three percent of street‐tree species (n = 108, total) were used in a lower proportion than their availability by feeding birds, and nearly all were nonnative in origin. Our findings highlight the positive influence of street trees on urban avifauna. In particular, our results suggest that improved street‐tree management in lower‐income communities would likely positively benefit birds. Further, our study provides support for the high value of native street‐tree species and select nonnative species as important habitat for feeding birds.

Patterns of biodiversity respond to habitat disturbances and different land-uses. Those patterns possibly vary according to the spatial scale under analysis. Although other studies have shown such responses for different systems, no study has ever demonstrated spatial-scale influences in subterranean terrestrial communities. Therefore, the objective of this paper was to analyze how land use and cave physical structure could influence the terrestrial cave invertebrate species composition. We also determined the influence of different spatial scale on the structure of invertebrate cave composition. We collected environmental data at local scale (e.g. cave size, substrate and environmental stability). For spatial scale we determined land uses at three different landscape scales; we gathered these data into circular areas of different sizes (50, 100 and 250 meters) with centroids in the cave entrances. We finally performed three Distance Based Linear Modeling analyses to test for differences among the predictability of environmental variables when comparing different spatial scales. The best explanatory variable for cave invertebrate similarities was the percentage of covering of the external environment by limestone outcrops. We confirm the scale-dependence hypothesis through the different patterns showed among distinct buffer areas. Models become more precise when larger scales were analyzed to explain cave invertebrate composition. This suggests that larger scales capture important environmental features that explain the cave fauna similarities more precisely. Additionally, we found a strong influence of limestone outcrops at all landscape scale structuring cave communities.

Wood-pastures are grazed systems resulting from a long-term use of natural woodlands by humans. These social-ecological systems, covering vast areas of Europe and other temperate regions, have both high biodiversity and economic values, so many are classified as High Nature Value Farmlands. However, in some regions a loss of spatial heterogeneity threatens this natural value. We investigated the potential contribution of tiny shrubby patches to increase spatial heterogeneity and functional diversity in wood-pasture landscapes. Specifically, we compared functional composition (Community Weighted Means) and functional diversity (Functional Dispersion and Functional Evenness) of assemblages of plants, beetles and lichens in those patches (252–3000 m2) and in the wood-pasture matrix. We found that shrubby patches and matrix harbour species assemblages with very distinct functional compositions in all studied taxonomic groups. Evergreen, woody, broad-leafed and fleshy-fruited are better represented in the patches. In beetles, the main differences were a greater prevalence of small-sized and fungivore species in the patches. Shrubby patches also mostly harboured lichens with fruticose- and foliose-broad growth forms, a greater humidity preference, and lower eutrophication tolerance. Moreover, the two indexes used to quantify functional diversity (Functional Dispersion and Functional Evenness) show that, overall, diversity is greater in patches than in the matrix; in patches Functional Dispersion is statistically higher for plants, and Evenness is statistically higher for beetles and lichen. These differences are all consistent with the very distinct ecological conditions in the matrix and patches. The greater overall functional diversity of shrubby patches, and the major differences in functional composition between patches and matrix, observed for all taxa, indicate that these patches greatly enhance the functional diversity of species assemblages in wood-pasture landscapes. Consequently, preserving and promoting tiny shrubby patches is a potentially valuable low-cost management tool to increase biodiversity and improve ecosystem functioning in wood-pasture landscapes., Doctoral and post-doctoral grants: (PD/BD/106044/2015), (SFRH/BPD/88056/2012), (SFRH/BPD/118635/2016), and (SFRH/BPD/101983/2014).

Non-crop habitat adjacent to crops may be important for enhancing the activity of natural enemies in crops. However, it is not always clear whether natural enemies that are active in non-crop habitats actually contribute to pest suppression in adjacent crop habitats. We hypothesised that parasitic wasps that utilise the same hosts can be segregated between crop and non-crop habitats in an agro-ecosystem. We tested this hypothesis using the light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), in vineyards and adjacent native vegetation. We experimentally measured the parasitism rate of larval E. postvittana at six and eight sites in both vineyards and the adjacent native vegetation in two consecutive years. Wild larval Tortricidae were also collected at each experimental site to assess their diversity and related parasitoids. Parasitised hosts were then identified using a PCR-based protocol to examine the parasitoids’ host ranges. The parasitoid Therophilus unimaculatus (Turner) (Hymenoptera: Braconidae) was most active in non-crop native vegetation, whereas Dolichogenidea tasmanica (Cameron) (Hymenoptera: Braconidae) parasitised the most larvae in vineyards. Parasitism of E. postvittana by D. tasmanica was higher on grape than on plantain, which indicates that host plants influence activities in different habitat. Both species shared the same range of tortricid hosts. Overall, our results indicate the two key parasitoids that attack E. postvittana differ in their pattern of habitat use. The native vegetation adjacent to crops may not enhance the activity of some natural enemies for pest control in an agricultural ecosystem. Refereed/Peer-reviewed

Estudar a dinâmica e distribuição de lepidópteros desfolhadores é importante porque essas espécies são pragas importantes do eucalipto. Mais de très milhões de hectares estão plantados com eucalipto no Brasil, embora esse gênero não seja nativo daqui. O objetivo deste estudo foi documentar os índices de freqüência e constância de lepidópteros pragas de Eucalyptus grandis Hill ex Maiden (Myrtaceae) coletados com cinco armadilhas luminosas (repetiçães) em diferentes habitats. As primeira e segunda armadilhas foram instaladas em um plantio de eucalipto a 400 e 200 metros da transição com uma área de vegetação nativa (Mata Atlântica); a terceira na zona de transição e as quarta e quinta na vegetação nativa a 200 e 400 metros da zona de transição. As espécies de pragas primárias, mais freqüentes, foram Stenalcidia grosica Schaus, 1901 e Thyrinteina leucoceraea Rindge, 1961 (Geometridae), no plantio de eucalipto a 400 e 200 metros da transição com a vegetação nativa. Na vegetação nativa a 200 metros da transição, Oxydia vesulia Cramer, 1779 (Geometridae), com 33,33% e Eupseudosoma involuta Sepp, 1855 e Eupseudosoma aberrans Schaus, 1905 (Arctiidae), na zona de transição, com 16,27% e 15,22% dos indivíduos coletados, respectivamente, foram as espécies pragas primárias mais freqüentes nesses habitats. Áreas de vegetação nativa de Mata Atlântica são mais espacialmente heterogêneas e abundantes em plantas hospedeiras que em plantações. A elevada diversidade de espécies dentro da vegetação nativa ajuda o contróle biológico natural de insetos herbívores em áreas próximas com espécies de eucaliptos. Study of the dynamics and distribution of lepidopteran defoliators is important because some of them are major pests of eucalyptus. More than 3,000,000 ha of eucalyptus are now planted in Brazil even though the genus is not native there. The goal of this study was to document the frequency and constancy indexes of lepidopteran pests of Eucalyptus grandis Hill ex Maiden (Myrtaceae) collected with 5 light traps (replicates) in different habitats. The first and second traps were installed in a eucalyptus plantation at 400 and 200 m, respectively, from the interface with a native vegetation area (Atlantic Rainforest); the third in the interface and the fourth and the fifth in native vegetation at 200 and 400 m, respectively, from the interface zone. The most frequent primary pest species were Stenalcidia grosica Schaus, 1901 (Geometridae) and Thyrinteina leucoceraea Rindge, 1961 (Geometridae) with greater frequencies in the eucalyptus plantation at 400 and 200 m from the interface with the na- tive vegetation. In the native vegetation at 200 m from the interface Oxydia vesulia Cramer, 1779 (Geometridae) (33.33%) was the most frequently collected primary pest species, and in the interface zone, Eupseudosoma involuta Sepp, 1855 (16.27%), and Eupseudosoma aberrans Schaus, 1905 (Arctiidae) (15.22%) were the most frequently collected primary pest species. Native vegetation areas of Atlantic Rainforest are more spatially heterogeneous and abundant in host plant species than eucalypt plantations and the high level of species diversity within native vegetation helps to provide natural biological control of herbivorous insects in nearby areas reforested with eucalyptus species.

The temperate grazing region of southeastern Australia is experiencing a rapid decline in tree cover that threatens key ecosystem functions. Graziers are stewards of most of the trees remaining outside reserves, and hold the power to reverse the decline. Influencing graziers' decision making about vegetation management requires an understanding of their landscape values. We asked 25 graziers to photograph features they considered significant on their farms. Their choices were analyzed using viewsheds, the spatial delineations of all areas visible in a photograph. Photos taken by landholders depicted woody vegetation more often than would be expected by chance, particularly the isolated and scattered trees that are declining most rapidly. Grazier awareness and appreciation of isolated and scattered trees should be harnessed by policymakers keen to reverse their decline. More generally, our work demonstrates the utility of simultaneously employing photo-elicitation and quantitative viewshed analysis. © 2011 Taylor & Francis Group, LLC.

Vegetation fires burnt an average 200,000 ha annually in the Mediterranean Basin between 1960 and 1970 ; the figure attained over 400,000 ha in the 1970’s and over 600,000 ha in the 1980's. This three fold increase over 20 years is turning into an annual summer-catastrophe in the Basin, in spite of heavy investments and large budget expenditure spent to prevent and combat the scourge. The paper gives detailed figures of number and acreage of fires in the various countries of the Basin, analyses the causes and evolutionary trends ; some further regional details are provided for southern France. The cost of preventing and combatting vegetation wild fires is evaluated for each country. The global cost for the Basin is in the vicinity of one billion U.S.$, as an annual average in the 1980's. But this figure does not take into account a number of havocs which are difficult to quantify such as : erosion, sedimentation, the silting up of reservoirs, floodings, loss of nutrients, hence decrease of fertility and productivity ; loss of wildlife and game, of amenities and aesthetic value, etc. The author advocates an expansion of research, demonstration and education of the public and politicians on the use of prescribed burning in conjunction with the systematic utilisation of browsing animals (cervidae, goats, camelidae) in order to reduce the fuel buildup, hence fire hazards and the ever increasing financial burden on rural communities , not to speak of losses in human life., Le Houérou Henri Noël. Vegetation wild fires in the mediterranean basin: evolution and trends. In: Ecologia mediterranea, tome 13 n°4, 1987. Influence of fire on the stability of mediterranean forest ecosystems. Giens (France) 23-26/03/1987. pp. 13-24.