Influence of plant growth-promoting bacteria on leaf carbon and nitrogen metabolism of two drought-stressed neotropical tree species: a metabolomic approach.

Deforestation of Atlantic Forest has caused prolonged drought events in the last decades. The need for reforestation is growing, and the development of native seedlings that are more tolerant to drought stress is necessary. A biotechnological tool that improves plant tolerance is the use of plant growth-promoting bacteria (PGPB) as inoculants. Two species of PGPB were inoculated in drought-stressed seedlings of two neotropical tree species that have been used in environmental restoration programs: Cecropia pachystachya and Cariniana estrellensis. Biometrical, physiological, and metabolomic parameters from carbon and nitrogen pathways were evaluated. We found that the PGPB positively influenced photosynthesis and growth parameters in both trees under drought. The enzymes activities, the tricarboxylic acid cycle intermediates, the amino acids, and protein contents were also influenced by the PGPB treatments. The results allowed us to find the specific composition of secondary metabolites of each plant species. This study provides evidence that there is not a single mechanism involved in drought tolerance and that the inoculation with PGPB promotes a broad-spectrum tolerance response in Neotropical trees. The inoculation with PGPB appears as an important strategy to improve drought tolerance in Atlantic Forest native trees and enhance environmental restoration programs' success. MAIN CONCLUSION: The association with plant growth-promoting bacteria improved the tolerance to drought in Neotropical trees through biochemical, physiological, and biometrical parameters. This can enhance the success of forest restoration programs.

Juvenile Plant-Microbe Interactions Modulate the Adaptation and Response of Forest Seedlings to Rapid Climate Change.

The negative impacts of climate change on native forest ecosystems have created challenging conditions for the sustainability of natural forest regeneration. These challenges arise primarily from abiotic stresses that affect the early stages of forest tree development. While there is extensive evidence on the diversity of juvenile microbial symbioses in agricultural and fruit crops, there is a notable lack of reports on native forest plants. This review aims to summarize the critical studies conducted on the diversity of juvenile plant-microbe interactions in forest plants and to highlight the main benefits of beneficial microorganisms in overcoming environmental stresses such as drought, high and low temperatures, metal(loid) toxicity, nutrient deficiency, and salinity. The reviewed studies have consistently demonstrated the positive effects of juvenile plant-microbiota interactions and have highlighted the potential beneficial attributes to improve plantlet development. In addition, this review discusses the beneficial attributes of managing juvenile plant-microbiota symbiosis in the context of native forest restoration, including its impact on plant responses to phytopathogens, promotion of nutrient uptake, facilitation of seedling adaptation, resource exchange through shared hyphal networks, stimulation of native soil microbial communities, and modulation of gene and protein expression to enhance adaptation to adverse environmental conditions.

How is the water footprint of the species Vachellia farnesiana, Amburana cearensis, and Handroanthus impetiginosus influenced by abiotic stresses as water deficit and salinity?

In semi-arid regions, is necessary to explore strategies to mitigate abiotic stresses such as water deficit and salinity. This study aimed to evaluate the stress tolerance capacity of three species subjected to different water regimes and salinity levels, based on dry matter production and water use efficiency (WUE). The species Handroanthus impetiginosus, Vachellia farnesiana, and Amburana cearensis were evaluated in combination with different water regimes (50%, 75%, and 100% of reference evapotranspiration - ET0) and salinity levels (0.18, 1.50, and 1.90 dS m-1). The results show that biomass accumulation increased at 50% and 75% ET0, while the WUE decreased at 100% ET0. The salinity level (1.90 dS m-1) caused reductions in leaf dry biomass (LDB), total dry biomass (TDB), LDB/TDB ratio, and WUE. The negative effects of high salinity on plant height were greater with the application of 75% ET0. The highest WUE was obtained at 50% ET0 for A. cearensis and H. impetiginosus, while V. farnesiana obtained the highest WUE at 75% ET0. A. cearensis exhibited the highest biomass accumulation (2.58 g) and WUE (0.21 g L-1). Overall, the species can tolerate drought and salinity conditions, being sensitive to high salinity concentrations during their initial growth.

The Caatinga is characterized by low water availability and soil salinization. Therefore, assessing the ability of native species to cope with these conditions allows for their utilization in reforestation programs in drought and salinity-exposed environments. Studies on the combined effects of these factors are scarce. The results indicated that native species show tolerance to drought and salinity conditions, albeit with some reductions in biomass production and water use efficiency at high NaCl concentrations. Among the species, A. cearensis performed the best under water and salinity stress conditions.

Artificial neural networks and adaptive neuro-fuzzy inference systems for prediction of soil respiration in forested areas southern Brazil.

The purpose of this study was to estimate the temporal variability of CO2 emission (FCO2) from O2 influx into the soil (FO2) in a reforested area with native vegetation in the Brazilian Cerrado, as well as to understand the dynamics of soil respiration in this ecosystem. The database is composed of soil respiration data, agroclimatic variables, improved vegetation index (EVI), and soil attributes used to train machine learning algorithms: artificial neural network (ANN) and an adaptive neuro-fuzzy inference system (ANFIS). The predictive performance was evaluated based on the mean absolute error (MEA), root mean square error (RMSE), mean absolute percentage error (MAPE), agreement index (d), confidence coefficient (c), and coefficient of determination (R2). The best estimation results for validation were FCO2 with multilayer perceptron neural network (MLP) (R2 = 0.53, RMSE = 0.967 µmol m-2 s-1) and radial basis function neural network (RBF) (R2 = 0.54, RMSE = 0.884 µmol m-2 s-1) and FO2 with MLP (R2 = 0.45, RMSE = 0.093 mg m-2 s-1) and RBF (R2 = 0.74, 0.079 mg m-2 s-1). Soil temperature and macroporosity are important predictors of FCO2 and FO2. The best combination of variables for training the ANFIS was selected based on trial and error. The results were as follows: FCO2 (R2 = 16) and FO2 (R2 = 29). In all models, FCO2 outperformed FO2. A primary factor analysis was performed, and FCO2 and FO2 correlated best with the weather and soil attributes, respectively.

Pioneer Tree Bellucia imperialis (Melastomataceae) from Central Amazon with Seedlings Highly Dependent on Arbuscular Mycorrhizal Fungi.

Bellucia imperialis is one of the most abundant pioneer tree species in anthropized areas of the Central Amazon, and has ecological importance for the environmental resilience of phosphorus (P)-depleted areas. Thus, we investigated whether B. imperialis depends on symbiosis with arbuscular mycorrhizal fungi (AMF) to grow and establish under the edaphic stresses of low nutrient content and low surface moisture retention capacity of the substrate. We tried three AMF inoculation treatments: (1) CON-no mycorrhizae; (2) MIX-with AMF from pure collection cultures, and (3) NAT-with native AMF, combined with five doses of P via a nutrient solution. All CON treatment seedlings died without AMF, showing the high mycorrhizal dependence of B. imperialis. Increasing P doses significantly decreased the leaf area and shoot and root biomass growth for both the NAT and MIX treatments. Increasing P doses did not affect spore number or mycorrhizal colonization, but decreased the diversity of AMF communities. Some species of the AMF community showed plasticity, enabling them to withstand shortages of and excess P. B. imperialis was shown to be sensitive to excess P, promiscuous, dependent on AMF, and tolerant of scarce nutritional resources, highlighting the need to inoculate seedlings to reforest impacted areas.

Perspectivas indígenas antirracistas sobre o etnogenocídio: contribuições para o reflorestamento do imaginário / Perspectivas indígenas antirracistas sobre el etnogenocidio: aportes a la reforestación de lo imaginario / Anti-racist indigenous perspectives on ethnogenocide: contributions to the reforestation of our imaginary

Resumo O artigo analisa as especificidades do racismo anti-indígena e sua relação com os marcos temporais da colonização. Em uma abordagem qualitativa e bibliográfica, elenca eixos do apagamento das identidades indígenas (etnogenocídio). São eles, a exigência de habitação em terra demarcada; a língua indígena; a aparência estereotipada e as noções de "descendente" e "pardo". Foram lidos 37 Trabalhos de Conclusão do Curso de Licenciatura Indígena da Mata Atlântica, da Universidade Federal de Santa Catarina, de autoria de acadêmicos guarani. Os argumentos centrais destes trabalhos foram enfatizados, sobretudo os relativos à identidade indígena guarani e à branquitude. Através da Plataforma Scielo, foi realizada análise dos artigos sobre branquitude, publicados entre 2018 e 2022. Nela foi constatado um apagamento das questões indígenas. Nos trabalhos guarani foram apontadas as especificidades do racismo anti-indígena, congregadas na categoria etnogenocídio. A pesquisa conclui apontando a importância das cosmogonias indígenas e suas temporalidades como meios de reflorestar o imaginário.

Resumen El artículo analiza las especificidades del racismo antiindígena y su relación con los hitos temporales de la colonización. En un enfoque cualitativo y bibliográfico, enumera ejes de borradura de las identidades indígenas (etnogenocidio). Ellos son: el requisito de vivienda en terrenos demarcados; la lengua indígena; la apariencia estereotipada y las nociones de "descendiente" y "moreno". Fueron leídos 37 Trabajos Finales de la Carrera Indígena de la Mata Atlántica, de la Universidad Federal de Santa Catarina, escritos por académicos guaraníes. Se enfatizaron los argumentos centrales de estas obras, especialmente los relativos a la identidad indígena guaraní y la blanquitud. A través de la Plataforma Scielo se realizó un análisis de artículos sobre la blanquitud, publicados entre 2018 y 2022. La investigación reveló una eliminación de las cuestiones indígenas. En las obras guaraníes se destacaron las especificidades del racismo antiindígena, agrupadas en la categoría de etnogenocidio. La investigación concluye señalando la importancia de las cosmogonías indígenas y sus temporalidades como medios de reforestación del imaginario.

Abstract This research paper analyzes the specificity of anti-indigenous racism and its relationship with the temporal milestones of colonization. In a qualitative and bibliographical approach, it lists axes of erasure of indigenous identities (ethnogenocide). They are: the requirement for living on demarcated land; the indigenous language; the stereotypical appearance and the notions of "descendant" and "brown". 37 Final Papers from the Atlantic Forest Indigenous Degree Course, from the Federal University of Santa Catarina, authored by Guarani academics, were read. The central arguments of these works were emphasized, especially those relating to Guarani indigenous identity and whiteness. Through the Scielo Platform, an analysis of articles on whiteness, published between 2018 and 2022, was carried out. It revealed an erasure of indigenous issues. In Guarani works, the specificity of anti-indigenous racism were highlighted, grouped under the ethnogenocide category. The research conclusion points out the importance of indigenous cosmogonies and their temporalities as means of reforesting the imagination.

Evaluating tree survival and modeling initial growth for Atlantic Forest restoration / Avaliação da sobrevivência e modelagem do desenvolvimento inicial de árvores para restauração da Mata Atlântica

ABSTRACT: Ecological restoration has become an important complementary practice to protect natural resources and preserve biodiversity. However, native species may be used in restoration programs in ways that do not optimize their performance. This research evaluated the survival and to model the initial growth of 15 native tree species planted in "filling" and "diversity" lines in the post-planting phase of a restoration experiment in the subtropics of the Brazilian Atlantic Forest. We measured survival rate (%) one year after planting and collar diameter (mm), total height (m), crown projection area (m²) and crown volume (m³) in the first 48 months after planting. Growth modeling for each variable and species was based on the non-linear mathematical Logistic, Gompertz, and Chapman-Richards models. Model selection for each variable/species was supported by the Akaike Information Criterion, standard error of the estimate, and coefficient of determination. The highest survival rates were reported for Cordia americana, Gochnatia polymorpha, Inga uruguensis, Peltophorum dubium, Prunus sellowii e Zanthoxylum rhoifolium (91.7%) and for Solanum mauritianum (90.3%). The species with faster growth were, by increasing order, Mimosa scabrella, Trema micrantha, Solanum mauritianum and Croton urucurana. With a better understanding of the initial developmental potential of tree species, it is possible to increase the species and functional diversity of the filling group. There was no single model capable of describing the variables analyzed and different models were needed to describe different characteristics and species.

RESUMO: A restauração ecológica tornou-se uma importante atividade complementar para proteger os recursos naturais e conservar a biodiversidade. No entanto, as espécies nativas podem estar a ser utilizadas em programas de restauração de formas que não otimizam as suas características. O objetivo deste trabalho foi avaliar a sobrevivência e modelar o desenvolvimento inicial de 15 espécies arbóreas nativas plantadas em linhas de "preenchimento" e "diversidade" na fase de pós-plantio numa experiência de restauração nos subtrópicos da Mata Atlântica Brasileira. Avaliou-se a taxa de sobrevivência (%) um ano após o plantio e o diâmetro do colo (mm), a altura total (m), a área de projeção de copa (m²) e o volume de copa (m³) nos primeiros 48 meses após o plantio. A modelagem de crescimento para cada variável e espécie foi baseada nos modelos matemáticos não lineares: Logístico, Gompertz e Chapman-Richards. A seleção do modelo para cada variável/espécie teve como base o Critério de Informação de Akaike, erro padrão da estimativa e coeficiente de determinação. Os percentuais de sobrevivência mais altos foram para Cordia americana, Gochnatia polymorpha, Inga uruguensis, Peltophorum dubium, Prunus sellowii e Zanthoxylum rhoifolium (91,7%) e para Solanum mauritianum (90,3%). As espécies de crescimento mais rápido, por ordem crescente, foram: Mimosa scabrella, Trema micrantha, Solanum mauritianum e Croton urucurana. Com o conhecimento do potencial de desenvolvimento inicial das espécies, é possível aumentar a diversidade de espécies e funcional do grupo de preenchimento. Não houve um modelo único capaz de descrever todas as variáveis de desenvolvimento analisadas. Foram necessários diferentes modelos para descrever as diferentes características e as diferentes espécies.

Sensitivity of eucalyptus (Eucalyptus urograndis) plants to subdoses of the herbicide dicamba / Sensibilidade de plantas de eucalipto (Eucalyptus urograndis) à subdoses do herbicida dicamba

In view of the widespread increase in herbicide-resistant weeds, biotechnology companies have developed dicamba-tolerant soybean and cotton cultivars. This technology can, however, increase the risk of the productdrifting to adjacent areas.This study was developed with the objective of the to evaluate the phytotoxicity and biometric variables of young eucalyptus plants exposed to subdoses of the herbicide dicamba. The experiment was carried out under field conditions in Rio Verde, state of Goiás, Brazil. The treatments were represented by the application of 0 (control), 7.5, 15, 30, 60, 120 or 240 g ae ha-1of dicamba 45 days after the seedlings were planted in the field. In terms of phytotoxicity, the dicamba doses of 120 and 240 g ae ha-1caused greater damage to the eucalyptus plants in all periods of evaluation. The predominant symptoms were epinasty, increased number of shoots and necrosis and senescence of young branches and leaves. The herbicide doses of 120 and 240 g ae ha-1 significantly compromised plant height and diameter, number of branches and dry mass of leaves and roots, interfering with the growth and development of the eucalyptus crop. The results indicate that the effect of subdoses of the herbicide dicamba can interfere with the proper development of young eucalyptus plants, which may cause losses in the initial plantingphase and future losses for producers.(AU)

Em decorrência do aumento generalizado de plantas daninhas com resistência a herbicidas, empresas de biotecnologia desenvolveram cultivares de soja e algodão tolerantes ao herbicida dicamba. Essa tecnologia pode, no entanto, aumentar o risco do produto ser deslocado para áreas adjacentes às aplicadas. Neste trabalho objetivou-seavaliar a fitotoxicidade evariáveis biométricas de plantas jovens de eucalipto tratadas com subdoses do herbicida dicamba. O experimento foi realizado em condições de campo em Rio Verde, Goiás, Brasil. Os tratamentos foram representados pela aplicação de 0 (testemunha), 7,5, 15,30, 60, 120 ou 240 g ea ha-1de dicamba aos 45 dias após o plantio das mudas no campo. Em termos de fitotoxicidade, as doses de dicamba de 120 e 240 g ea ha-1causaram maiores danos às plantas de eucalipto em todos os períodos de avaliação. Os sintomas predominantes foram epinastia, aumento do número de brotações e necrose e senescência de ramos e folhas jovens. As doses de herbicidas de 120 e 240 g ea ha-1comprometeram significativamente a altura e diâmetro das plantas, número de ramos e massa seca de folhas, caules e raízes, interferindo no crescimento e desenvolvimento da cultura do eucalipto. Os resultados indicam que o efeito de subdoses do herbicida dicamba pode interferir no bom desenvolvimento de plantas jovens de eucalipto, podendo causar prejuízos na fase inicial de plantio e prejuízos futuros para os produtores.(AU)

Morpho-Physiological Responses of Two Multipurpose Species from the Tropical Dry Forest to Contrasting Light Levels: Implications for Their Nursery and Field Management.

Understanding the responses that some plants exhibit to acclimatize and thrive in different light environments can serve as a guideline to optimize their production or establishment. Morpho-physiological changes in Crescentia alata and Enterolobium cyclocarpum were examined in response to varying light levels: 25%, 35%, 55% and 70% of photosynthetic photon flux density (PPFD) of total solar radiation. One-month-old seedlings were subjected to the light treatments; subsequently, the effects on morphology, photosynthetic capacity, nutrient status, non-structural carbohydrate reserves (NSC) and growth were evaluated in three-month-old seedlings. Light levels affected several morpho-physiological parameters. C. alata responded better to higher light levels and E. cyclocarpum to lower levels. Particularly, C. alata with 70% PPFD increased its size in height and diameter, and accumulated more biomass in leaves, stems, and roots; it also exhibited higher net assimilation rates, improved nitrogen and phosphorus status and growth. In contrast, E. cyclocarpum with 25% PPFD increased aboveground biomass, nitrogen levels and NSC in leaves. Both species show morpho-physiological changes that determine their ability to acclimatize to different light conditions. This serves as a basis for designing better management strategies in the nursery or field by defining the light environments conducive to a proper functioning.

Ephemeral forest regeneration limits carbon sequestration potential in the Brazilian Atlantic Forest.

Although deforestation remains widespread in the tropics, many places are now experiencing significant forest recovery (i.e., forest transition), offering an optimistic outlook for natural ecosystem recovery and carbon sequestration. Naturally regenerated forests, however, may not persist, so a more nuanced understanding of the drivers of forest change in the tropics is critical to ensure the success of reforestation efforts and carbon sequestration targets. Here we use 35 years of detailed land cover data to investigate forest trajectories in 3014 municipalities in the Brazilian Atlantic Forest (AF), a biodiversity and conservation hotspot. Although deforestation was evident in some regions, deforestation reversals, the typical forest transition trajectory, were the prevalent trend in the AF, accounting for 38% of municipalities. However, simultaneous reforestation reversals in the region (13% of municipalities) suggest that these short-term increases in native forest cover do not necessarily translate into persistent trends. In the absence of reversals in reforestation, forests in the region could have sequestered 1.75 Pg C, over three times the actual estimated carbon sequestration (0.52 Pg C). We also showed that failure to distinguish native and planted forests would have masked native forest cover loss in the region and overestimated reforestation by 3.2 Mha and carbon sequestration from natural forest regeneration by 0.37 Pg C. Deforestation reversals were prevalent in urbanized municipalities with limited forest cover and high agricultural productivity, highlighting the importance of favorable socioeconomic conditions in promoting reforestation. Successful forest restoration efforts will require development and enforcement of environmental policies that promote forest regeneration and ensure the permanence of regrowing forests. This is crucial not only for the fate and conservation of the AF, but also for other tropical nations to achieve their restoration and carbon sequestration commitments.

A comprehensive experimental assessment of glyphosate ecological impacts in riparian forest restoration.

Competition with invasive grasses is one of the most important drivers of tree planting failures, especially in tropical forests. A widely disseminated weeding approach has been glyphosate spraying, the most used herbicide globally in forestry and ecosystem restoration. However, glyphosate use in restoration is highly controversial and requires further studies to elucidate its effects on restoration processes and the environment. We evaluated the use of glyphosate in riparian forest restoration and its impacts on tree planting costs, weed control efficiency, planted seedling performance, herbaceous and woody species regeneration, soil bacteria, and environmental contamination, using mowing treatments as a reference and based on a controlled experiment established in the Brazilian Atlantic Forest. Glyphosate spraying reduced by one-half and one-third the accumulated aboveground biomass of, respectively, weeds in general and of the invasive grass Urochloa decumbens compared to mowing treatments, and it reduced the cost by half. The performance of planted tree seedlings was markedly favored by glyphosate spraying compared to mowing treatments, as expressed by improved seedling height (~twice higher), crown area (~5× higher), and basal area (~5× higher); the regeneration of both native woody and ruderal herbaceous plants were also enhanced. Neither glyphosate nor its metabolite Aminomethylphosphonic acid (AMPA) residues were detected in either water runoff or soil samples, but they were found at relatively high concentrations in the runoff sediments (from 1.32 to 24.75 mg/kg for glyphosate and from 1.75 to 76.13 mg/kg for AMPA). Soil bacteria communities differed before and after glyphosate spraying in comparison to mowing plots (without glyphosate). Glyphosate spraying was far more cost effective than mowing for controlling U. decumbens and greatly improved the performance of planted tree seedlings and natural regeneration, while not leaving residues in soil and water. However, the changes in the structure of bacterial communities and high concentration of glyphosate and AMPA residues in runoff sediments highlight the need for caution when using this herbicide in riparian buffers. We present alternatives for reducing glyphosate use and minimizing its risks in tree planting initiatives.

Willingness to Pay for Gray and Green Interventions to Augment Water Supply: A Case Study in Rural Costa Rica.

Many rural communities in developing countries experience severe water shortages, limiting their capacity for self-sustainability. This study used contingent valuation and choice experiment methods and in-person interviews to estimate household willingness to pay (WTP) for gray and green interventions to augment water supply in rural Costa Rica. In particular, we examined residents' preferences for well construction, as a form of gray intervention, and reforestation, as a form of green intervention, aimed at alleviating water shortages. Household WTP to reduce annual water shortage by one day varied between $0.85 (95% CI = 0.77-0.94) and $1.32 (95% CI = 1.08-2.56) per month depending on the project. The results also indicated that households were willing to pay $2.28 (95% CI = 1.36-3.21) and $3.51 (95% CI = 2.57-4.44) per month to increase forest cover in the watershed by 140-180 and 300-340 ha, respectively, assuming no additional water provision from the reforestation project. Nonwater-related benefits comprised 25-34% of the WTP for green intervention, depending on the acreage scenario. We also observed that, even without the nonwater-related ecosystem service benefits associated with reforestation, the value of water from green intervention exceeded the corresponding value of water from gray intervention. The disparity between preferences for water obtained from gray and green intervention may be due to differences in corresponding timing, uncertainty, quality of additional water made available from the considered projects, and differences in value elicitation methods.

Changes in the constituents of the "Bosque de Agua" of the Sierra Cruces-Ajusco-Chichinautzín, Mexico, an area with payment for environmental services.

The "Bosque de Agua", to the west and south of Mexico City, which is the fifth largest city in the world, has historically suffered disturbances in forest cover, with a consequent reduction in the environmental services provided. Changes in the state of the forests between 1994 and 2017 are here analyzed in terms of the annual net change in area of the different cover densities and the different change processes. In general, the net change was favorable in all cases: forest improvement vs. forest degradation, reforestation vs. deforestation, and afforestation vs. land use change. There were changes in 16.03% of the Bosque de Agua: recovery in 11.09% and disturbance in 4.94%. This marked recovery is the result of the protected status of two-thirds of the forest, the payment for hydrological environmental services in 29.33% of the forest, as of 2003, and the continuous programs of reforestation, fire control and surveillance by the local communities, circumstances that have allowed the recovery to exceed the disturbance in most of the Bosque de Agua. One-third of the forest disturbance is concentrated in six of the 35 municipalities in the southern region, caused by clandestine logging by organized gangs, due to the state of ungovernability that reigns in these municipalities. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12665-021-10025-w.

Re-establishment of cavity-nesting bee and wasp communities along a reforestation gradient in southern Amazonia.

Global initiatives to reforest degraded areas have intensified in recent years, in an attempt to reverse the environmental impacts of habitat loss on species and ecosystem provided by them. However, the effectiveness of such reforestation initiatives in re-establishing biodiversity is still poorly understood. Here, we test how reforestation type and intensity applied to deforested areas affect the reestablishment of communities of cavity-nesting bees and wasps. We deployed experimental trap-nests along a reforestation gradient of increasing structural similarity to primary forest, after 18 years of reforestation. We found that reestablishment, in terms of abundance and richness of both bees and wasps, was greatest at an intermediate point along the reforestation gradient. However, these communities were highly dissimilar to primary forest, and recovery of intact insect community composition was only achieved when reforestation was more similar in structure to natural forests. This effect was more pronounced for bees than for wasps. Our findings suggest that along the reforestation gradient, services provided by wasps will be more easily recovered than those provided by bees. Our results have important implications for the challenges of restoring and maintaining species biodiversity as well as their associated ecosystem services.

Diversity and community structure of ectomycorrhizal fungi in Pinus thunbergii coastal forests bordering the Yellow Sea of China.

Ectomycorrhizas play a fundamental role in the function of forest ecosystems, being essential for plant nutrition absorption and soil quality. Many afforestation and reforestation programmes have begun to recover and maintain coastal forests in China, using pine species including Pinus thunbergii. We investigated the ectomycorrhizal colonization status of P. thunbergii in coastal pine forests of the Yellow Sea of China. We identified a total of 53 ectomycorrhizal fungal species in 74 soil samples collected from three sites and found that Thelephoraceae (10 spp.) and Russulaceae (8 spp.) were the most species-rich ectomycorrhizal fungal lineages. Russula sp. 1 was the most abundant species, accounting for 15.3% of the total ectomycorrhizal tips identified. Most of the remaining species were rare. At this small scale, host identity had no significant effect on the ectomycorrhizal fungal community composition (A = 0.036, P = 0.258), but sampling sites did (A = 0.135, P = 0.041). In addition, Na+ and K+ content and soil pH had significant effects on the ectomycorrhizal fungal community. The ectomycorrhizal fungal community associated with different host plants will become an important new direction for research, as ectomycorrhiza may have the potential to improve host capacity to establish in salt-stressed environments. This will provide a theoretical basis and technical support for saline soil reforestation and rehabilitation using pine species with compatible, native ectomycorrhizal fungi in Yellow Sea coastal areas.

Mining increases the prevalence of avian haemosporidian parasites in Northeast Amazonia.

Studies contrasting parasite prevalence and host-parasite community structure between pristine and disturbed environments will improve our understanding of how deforestation affects disease transmission and parasite extinction. To determine how infection rates of a common and diverse group of avian blood parasites (Plasmodium and Haemoproteus) respond to changes in avian host composition after mining, we surveyed 25 bird communities from pristine forests (two forest types: plateau and hillside) and reforested sites in Northeast Amazonia. Infection rates and both parasite and avian host community structure exhibited considerable variation across the deforestation gradient. In opposition to the emerging pattern of lower avian haemosporidian prevalence in disturbed tropical forests in Africa, we show that secondary forests had higher haemosporidian prevalence in one of the largest mining areas of Amazonia. The dissimilarity displayed by bird communities may explain, in part, the higher prevalence of Haemoproteus in reforested areas owing to the tolerance of some bird species to open-canopy forest habitat. On the other hand, deforestation may cause local extinction of Plasmodium parasites due to the loss of their avian hosts that depend on closed-canopy primary forest habitats. Our results demonstrate that forest loss induced by anthropogenic changes can affect a host-parasite system and disturb both parasite transmission and diversity.

Monitoring tropical forest succession at landscape scales despite uncertainty in Landsat time series.

Forecasting rates of forest succession at landscape scales will aid global efforts to restore tree cover to millions of hectares of degraded land. While optical satellite remote sensing can detect regional land cover change, quantifying forest structural change is challenging. We developed a state-space modeling framework that applies Landsat satellite data to estimate variability in rates of natural regeneration between sites in a tropical landscape. Our models work by disentangling measurement error in Landsat-derived spectral reflectance from process error related to successional variability. We applied our modeling framework to rank rates of forest succession between 10 naturally regenerating sites in Southwestern Panama from about 2001 to 2015 and tested how different models for measurement error impacted forecast accuracy, ecological inference, and rankings of successional rates between sites. We achieved the greatest increase in forecasting accuracy by adding intra-annual phenological variation to a model based on Landsat-derived normalized difference vegetation index (NDVI). The best-performing model accounted for inter- and intra-annual noise in spectral reflectance and translated NDVI to canopy height via Landsat-lidar fusion. Modeling forest succession as a function of canopy height rather than NDVI also resulted in more realistic estimates of forest state during early succession, including greater confidence in rank order of successional rates between sites. These results establish the viability of state-space models to quantify ecological dynamics from time series of space-borne imagery. State-space models also provide a statistical approach well-suited to fusing high-resolution data, such as airborne lidar, with lower-resolution data that provides better temporal and spatial coverage, such as the Landsat satellite record. Monitoring forest succession using satellite imagery could play a key role in achieving global restoration targets, including identifying sites that will regain tree cover with minimal intervention.

Nucleário, cardboard, or manual crowning: which maintenance technique is most cost-effective in tree seedling survival establishment?

In ecological restoration, one of the main challenges is to develop new methods, techniques, and incentives that both favour and reduce maintenance costs in restoration projects. Besides, post-planting maintenance is often neglected hampering seedling survival over time owing to alien grasses, which compete strongly with native plants for resources. To solve these issues, recently, an innovative technology called Nucleário has been developed in Brazil. Aiming to hinder alien competition filters, the Nucleário also attempts to condition a better microenvironment, reducing drought stress through the water storage tank, decreasing temperatures, which facilitates the survival and growth of seedlings in areas under restoration. Another method used to decrease alien grasses, which is inexpensive, is seedling crowning using cardboard lowing maintenance needs in restored areas. Cardboard has similar functions to Nucleário, such as protecting soil against loss of water and nutrients and reducing competition with invasive exotic grasses. Therefore, comparing them also with traditional manual weeding (i.e., clean-weeded crown by hoe), we aimed to verify which technique is most cost-efficient for seedling crown maintenance of Dipteryx alata Vog., which is an indigenous tree species with high economic value owing to its nuts. We tested three techniques in areas under restoration in the Cerrado, in the Environmental Protection Area "Córrego Guariroba" located in Campo Grande, Mato Grosso do Sul, Brazil. We monitored seedlings submitted to the three methods in the wet and the dry periods for biotic (competition with exotic grasses, herbivory, and growth) and abiotic (moisture and soil temperature) indicators. We observed that the Nucleário was the treatment that maintained the highest soil moisture, resulting in a larger canopy area. However, these effects do not reflect increases in the survival rate, diameter, and height of the seedlings. None of the treatments was effective in reducing herbivory. Nucleário was the most effective treatment in reducing the competition of seedlings with invasive grasses. Cardboard presented an implementation value 21.5 times lower than Nucleário and 1.2 times than manual crowning. Given the high purchase price, the Nucleário's cost-benefit ratio was very high compared to the crowning of cardboard and the manual weeding, which discourages us from recommending it for this species with high survival rates. Its project can be revised to decrease herbivory rates, as well as its efficiency tested in the short and long term in different ecosystems and species, particularly species susceptible to water stress.

Cinchona L. "Árbol de la Quina": repoblamiento y reforestación en el Perú / Cinchona L. "Quina Tree": Repopulation and reforestation in Peru

Resumen Este trabajo se centra en las recientes decisiones tomadas por el Ministerio de Agricultura del Perú sobre la recolección, propagación y siembra de especies de quina. Señalamos las deficiencias de estas decisiones a la luz de los avances en el conocimiento de la taxonomía y sistemática de Cinchona. Destacamos el papel de la ciencia analizando e informando sobre las decisiones en el uso sostenible de los recursos naturales.

Abstract This work focuses about the recent decisions made by the Ministry of Agriculture of Peru on the collection, propagation, and sowing of Cinchona species are reasons to point out the deficiencies of these decisions in light of advances in the knowledge of Cinchona taxonomy and systematics. We emphasize the role of the science analysing and informing about decisions in the sustainable use of natural resources.

Plant growth-promoting bacteria improve leaf antioxidant metabolism of drought-stressed Neotropical trees.

MAIN CONCLUSION: Plant growth-promoting bacteria association improved the enzymatic and non-enzymatic antioxidant pathways in Neotropical trees under drought, which led to lower oxidative damage and enhanced drought tolerance in these trees. Water deficit is associated with oxidative stress in plant cells and may, thus, negatively affect the establishment of tree seedlings in reforestation areas. The association with plant growth-promoting bacteria (PGPB) is known to enhance the antioxidant response of crops, but this strategy has not been tested in seedlings of Neotropical trees. We evaluated the effects of inoculation with two PGPB (Azospirillum brasilense and Bacillus sp.) on the antioxidant metabolism of Cecropia pachystachya and Cariniana estrellensis seedlings submitted to drought. We measured the activity of antioxidant enzymes and the content of non-enzymatic antioxidants in leaves, and biometrical parameters of the seedlings. In both tree species, drought decreased the activity of antioxidant enzymes and the content of non-enzymatic antioxidant compounds. For C. pachystachya, the enzymatic and non-enzymatic pathways were mostly influenced by A. brasilense inoculation, which enhanced ascorbate peroxidase (APX) and superoxide dismutase activities and positively affected the level of non-enzymatic antioxidant compounds. In C. estrellensis, A. brasilense inoculation enhanced APX activity. However, A. brasilense and Bacillus sp. inoculation had more influence on the non-enzymatic pathway, as both bacteria induced a greater accumulation of secondary compounds (such as chlorogenic acid, gallic acid, rutin and synapic acid) compared to that in non-inoculated plants under drought. For both species, PGPB improved biometrical parameters related to drought tolerance, as specific leaf area and leaf-area ratio. Our results demonstrate that PGPB induced antioxidant mechanisms in drought-stressed Neotropical trees, increasing drought tolerance. Thus, PGPB inoculation provides a biotechnological alternative to improve the success of reforestation programmes.