The fewer, the better fare: Can the loss of vegetation in the Cerrado drive the increase in dengue fever cases infection?

Several studies have reported the relationship of deforestation with increased incidence of infectious diseases, mainly due to the deregulation caused in these environments. The purpose of this study was to answer the following questions: a) is increased loss of vegetation related to dengue cases in the Brazilian Cerrado? b) how do different regions of the tropical savanna biome present distinct patterns for total dengue cases and vegetation loss? c) what is the projection of a future scenario of deforestation and an increased number of dengue cases in 2030? Thus, this study aimed to assess the relationship between loss of native vegetation in the Cerrado and dengue infection. In this paper, we quantify the entire deforested area and dengue infection cases from 2001 to 2019. For data analyses, we used Poisson generalized linear model, descriptive statistics, cluster analysis, non-parametric statistics, and autoregressive integrated moving average (ARIMA) models to predict loss of vegetation and fever dengue cases for the next decade. Cluster analysis revealed the formation of four clusters among the states. Our results showed significant increases in loss of native vegetation in all states, with the exception of Piauí. As for dengue cases, there were increases in the states of Minas Gerais, São Paulo, and Mato Grosso. Based on projections for 2030, Minas Gerais will register about 4,000 dengue cases per 100,000 inhabitants, São Paulo 750 dengue cases per 100,000 inhabitants, and Mato Grosso 500 dengue cases per 100,000 inhabitants. To reduce these projections, Brazil will need to control deforestation and implement public health, environmental and social policies, requiring a joint effort from all spheres of society.

Irrigated sugarcane crops improve the quality of soil organic carbon over time

The substitution of native vegetation in agricultural systems can cause several changes in the chemical and physical soil attributes, and in the dynamics of soil organic carbon. This study aimed to evaluate changes in soil physical attributes and carbon stock in soil organic matter fractions in irrigated sugarcane crops, as a function of land use and straw management practices over time, in the North of Minas Gerais State, Brazil. Four sugarcane fields with different ages and management systems were studied: Cane 6, Cane 7, Cane 8, and Cane 10. The data obtained were compared with a native vegetation area located near the sugarcane fields, and used as reference for unmanaged soil. In each system, soil samples were collected in the 0-10, 10-20, and 20-30 cm depth layers, to determine the physical attributes, the total organic carbon, and the physical fractions of the soil organic matter. We found that the sugarcane management with the maintenance of a part of the straw on the soil surface contributes to the preservation of the soil structure and the most stable fractions of organic carbon over time. However, in the regions with high annual mean temperature and in the irrigated systems, the soil tillage for the renewal of the sugarcane fields significantly decreases the total soil organic carbon.

Silvopastoral Systems Enhance Soil Health in the Amazon Region

Silvopastoral systems (SPS), an integrated farming system in which tropical grasses are combined with trees and shrubs, have been implemented in the last years in the Amazon region in order to mitigate the impacts generated by the traditional cattle ranching system. However, despite the multiple SPS’s benefits to soil and ecosystem, there is a paucity of comprehensive studies revealing the potential soil health (SH) restoration through SPS. Here, by developing an overall SH index using local native vegetation (Amazon rainforest) as a reference, we aimed to assess SH changes induced by the land transition from the traditional livestock production system to the SPS in the Colombian Amazon region. A chronosequence conformed by three areas: (i) native vegetation, (ii) traditional pasture and (iii) silvopastoral system was established in two study sites located in the Colombian Amazon, specifically in Caquetá State, the second hotspot of deforestation in the Amazon Basin. The results indicated high soil compaction and loss of macrofauna diversity and richness due to pasture management, causing a loss of 9% of soil capacity to function. In contrast, by integrating 31 soil indicators, our SH assessment revealed that SPS was an effective strategy for the recovery of SH, impacting positively multiple soil functions related to nutrient dynamics, water retention and supply, and biological activity.

Geoprocessing and Landscape Ecology for Assessment Fragmentation and Connectivity of the Habitats of the Microregion of Ceres, Goiás (Brazil)

This study aimed to map and evaluate the evolution of habitat fragmentation between 2009 and 2018, using the Microregion of Ceres (Goiás) as a sample reference, using principles of Landscape Ecology. The methodology comprised the mapping of the fragments in the two years analyzed, using the OLI/Landsat 8 sensor, using scenes 222/70 and 222/71. The SPRING 5.2 software was used, where the supervised classification was performed, applying the semi-automatic process. The computational algorithm applied to classify the scenes was Maxver, which classifies pixel by pixel and groups the information of each one into homogeneous regions. After extracting the fragments of native vegetation, the methodology proposed by Juvanhol et al. (2011), in which the fragments were grouped into classes: Very Small (MP) ≤5 hectares; Small (P) ≥5.01 and ≤10 hectares; Medium (M) ≥10.01 and ≤100 hectares and Large (G) ≥100.01 hectares. For the analysis based on metrics in Landscape Ecology, the ArcGis 9.2 Patch Analyst extension was used. The results showed the expansion of vegetation cover areas in the study area, concentrated on tops of hills, APP and legal reserves. However, they pointed out intense fragmentation of native vegetation, which hinders the performance of fragments as habitats. It is considered that, from the contemporary problem of degradation of natural environments to the detriment of economic development, studies like this are necessary in order to identify existing environmental problems and propose strategies to minimize and mitigate ecological imbalances.

Does the Reaction of Inflorescences and Flowers of the Invasive Prunus serotina Ehrh. to Various Herbicides Give Hope for Elimination of This Species from Polish Forests?

The North American Prunus serotina Ehrh. is an invasive neophyte widespread in Polish forests. Due to the negative impact of this species on native vegetation, the most effective methods of its removal from the stands have been searched for. Our research aimed to determine whether herbicides that were applied in spring 2020 influenced morphological features of inflorescences and flowers of P. serotina in the next year of vegetation (i.e., 2021). So far, the effects of herbicides used were analysed in the same year, no later than a few weeks after their application. The experiment was carried out on the research area of 2.7 ha located in the Zielonka Forest near Poznań in Poland (N 52.5330, E 17.1015). The response of 39 P. serotina trees to six different herbicides, containing sulfonylurea derivatives, glyphosate and phenoxy herbicides was investigated. The chemicals were applied directly to the tree, to the holes made in the trunk axis. The plant material included inflorescences from 10 control trees and 29 trees treated with different herbicides. Nine morphological inflorescence and flower features and three ratios were analysed. In total 200 inflorescences and 1000 flowers were measured. Statistically significant differences between inflorescence and flower features collected from trees treated with different herbicides were demonstrated. The largest ranges of values of the studied features were found in inflorescences and flowers collected from the control trees (C-WI, C-DWH). The greatest variability of the studied features was found for C-DWH. Compared to the control trees the reduction in inflorescence size, as well as the smaller number of flowers, were recorded in the trees treated with different herbicides, irrespective of an active substance content. The use of six different herbicides—with different active substance contents to control P. serotina proves to be effective.

The human-dimensions ecology of parrots reintroduced to a city: the Kākā (Nestor meridionalis) of Wellington, New Zealand.

<p>Conflict involving wildlife and people is globally common and is one of the more difficult challenges facing conservation. The increasing trend for wildlife to colonise, or be reintroduced, to cities increases the chances of conflict occurring. It is common for people to feed wildlife which leads to an increase in their local density. This concentrates their odours, fouling, noise, nesting, property damage and in some cases, can lead to attacks on people. Wherever they have been measured, attitudes to wildlife are generally positive and robust to some damage and conflict. Nonetheless, more negative attitudes and conflict among residents are particularly likely if the wildlife impose an economic cost. Understanding how wildlife use urban environments, what influences their habitat choices in cities, particularly their relationships with people (e.g., feeding), and how these could lead to conflict and deteriorating relationships with wildlife is essential for planning future reintroductions and preventing or mitigating conflict over wildlife in cities. Kākā (Nestor meridionalis) were reintroduced to Wellington City in 2002 and they are now commonly seen in city suburbs around the reintroduction site. The number and range of kākā appears to be increasing, as are reports of damage by kākā to public and private property. Most people report positive attitudes towards kākā, and some residents intentionally feed them. At these feeders, kākā appear to congregate in larger numbers. Recent research suggests that kākā feeding and damage may be initiating a conflict among residents, especially between neighbours who do and do not feed kākā. This can lead to deteriorating attitudes towards kākā, and native wildlife and conservation generally. The aims of this thesis are to better understand 1) which factors affect the presence of kākā on residential properties, 2) which factors lead to or exacerbate damage to these properties and 3) how damage affects resident attitudes towards kākā and avifauna conservation in general. I hypothesized that kākā will be in greater densities in areas proximal to native vegetation and close to their 2002 reintroduction site. I further predicted that the damage to properties will be more common and at a greater extent at sites where more people feed kākā. As this damage increases, it will negatively impact resident attitudes, especially where the damage imposes a cost on the resident. A postal survey sent to 600 residences at 25 stratified random sites (neighbourhoods) across Wellington City suburbs was used to quantify residents’ self-reports of kākā on properties, residential feeding activity, property damage and their attitudes to kākā and avian wildlife. A total of 309 surveys were returned (52%) with 301 entirely complete and used in the final analysis. The sites were also visited to quantify their environments, particularly topographical exposure, tree size and the number of emergent trees that were hypothesised, from my anecdotal observations and the literature, to potentially be important influences on kākā distribution. An information theoretic approach was used to test current hypotheses (models) for kākā abundance on properties and property damage by compiling a candidate set of 46 models for kākā abundance and 22 for kākā damage. A repeated measures, one-way ANOVA tests was used to determine if damage negatively affected resident attitudes. Residential feeding was found to be the strongest driver of kākā presence, followed by the proximity of native vegetation. The abundance of kākā, particularly the frequency with which kākā visit properties, was found to be the best explanatory variable for the presence and scale of property damage. Damage itself was not found to be a significant driver of increasingly negative attitudes. However, the few residents spending greater than $50 to repair damage showed significantly lower attitude scores compared to those that had no expenditures. Overall, resident attitudes towards the kākā in Wellington are generally positive. However, these findings suggest that there is a causative pathway leading from residential feeding of kākā to occurrences of increasingly negative attitudes and conflict among neighbours that are sensitive to the economic cost of damage. While conflict between people and kākā in Wellington is certainly present, it is not yet widespread. However, it is likely that instances of conflict involving kākā and people will only grow as the kākā population within the city continues to increase. There is a need to seek solutions to mitigate this conflict promptly, before it reaches a tipping point in which widespread negative attitudes will be difficult to change. Financial compensation and the discouraging of feeding are discussed as recommended solutions, tailored to findings in this thesis.</p>

Survival, predation, and behaviour of the Mahoenui giant wētā ('Deinacrida mahoenui': Anostostomatidae: Orthoptera)

<p>Introduced mammalian pests, such as rats (Rattus spp.), house mice (Mus musculus), brushtail possums (Trichosurus vulpecula), and European hedgehogs (Erinaceus europaeus), have been implicated in the suppression or extinction of many endemic invertebrate species in New Zealand, including the large-bodied giant wētā (Anostostomatidae: Deinacrida). The Mahoenui giant wētā (MGW; D. mahoenui) is the only lowland giant wētā species still naturally present on the mainland of New Zealand, where the last remaining individuals of the original population are currently restricted to an 187ha mainland reserve (Mahoenui Giant Wētā Scientific Reserve; MGWSR) in Mahoenui, western King Country. Having sought refuge in the introduced woody shrub, gorse (Ulex europaeus), these wētā have survived in the presence of introduced mammalian predators for almost six decades. However, due to natural succession, the reserve is gradually reverting to native bush and wētā monitoring data shows potential signs of population decline. Concerns for the species survival have been raised as it is unknown how wētā will cope in an altered habitat alongside mammalian predators. In chapter 2, we used 14-years’ of site-occupancy monitoring data to explore changes to the reserves’ gorse mosaic and MGW population. We additionally assessed the effect of abiotic covariates on MGW occupancy and detection probabilities in 2005 and 2018. Furthermore, we assessed mammalian pest population dynamics within the reserve over the past seven years. Significant changes to the reserve’s gorse mosaic were identified, whereby unbrowsed, tall bushes, which may provide less protection to wētā, are now dominant in 2018. Population trajectory analysis revealed the MGW population has decline since 2012. This result was consistent with naïve occupancy estimates and the increase in search time (0.3hrs/year) required to find wētā, suggesting the population is in a state of decline. Plot location was identified as an important covariate for predicting MGW occupancy in 2018, whereby plots in edge habitat, potentially being preferred or safer, had a higher occupancy probability. Mammalian pests (rats, house mice, brushtail possums, and European hedgehogs) appear to be present within the reserve year-round, populations peaking in summer and autumn. In chapter 3, we used radiotelemetry to explore MGW survival rates, movement patterns, and diurnal refuge use in gorse and native vegetation during summer (n=14), autumn (n=31), and spring (n=10). Survival rates, in relation to predation, revealed MGW inhabiting native vegetation were nine times more likely to be predated than those inhabiting gorse. This result suggests native species such as mahoe (Melicytus ramiflorus), and tree ferns (Dicksonia fibrosa and Cyathea spp.) do not provide good protection to MGW from mammalian predators. Assessment of movement behaviour revealed MGW move less in autumn (~3m/48hrs) compared to summer (~10m/48hrs) and spring (~8m/48hrs), and most commonly follow a movement pattern consistent with random-walk. Movement behaviour was also found to be temperature dependant, with both male and female MGW moving significantly further in warmer weather (>13.5°C). Radiotracked MGW were found to take refuge above 2.5m in the canopy of native vegetation, whereas in gorse habitat, wētā were most commonly found taking refuge between 0.62 – 2.38m in the denser foliage of unbrowsed gorse bushes. Furthermore, no radiotracked wētā were observed with another individual in autumn, compared to eight and 26 observations in summer and spring. In chapter 4, we attempted to identify potential mammalian predators of the MGW by analysing the stomach contents of ship rats (R. rattus; n=10), house mice (n=10), brushtail possums (n=5), and feral cats (Felis catus; n=2). Ship rats were identified as likely predators of MGW within the MGWSR. However, due to the limited number of stomachs and species analysed, further analysis is recommended. Collectively, these results provide an overview of the MGW reserve and population status, in addition to important ecological information that can be used to inform future management, monitoring, and translocation.</p>