Lurdes Silva - Academia.edu (original) (raw)

Papers by Lurdes Silva

Biodiversity Data Journal, Aug 3, 2023

Background The data presented here originated from field expeditions carried out between 2017 and... more Background The data presented here originated from field expeditions carried out between 2017 and 2018, within the framework of Forest-Eco project: "Towards an Ecological and Economic valorisation of the Azorean Forest". The project aimed to quantify the ecological value of the Azorean forests, including carbon accumulation and to design and propose measures that could further enhance forest sustainability. For that, 90 forest plots were sampled on three Azores islands-São Miguel, Terceira and Pico-equally distributed into natural

Plant Systematics and Evolution, 2015

Biodiversity Data Journal

The data presented here originated from field expeditions carried out between 2017 and 2018, with... more The data presented here originated from field expeditions carried out between 2017 and 2018, within the framework of Forest-Eco2 project: "Towards an Ecological and Economic valorisation of the Azorean Forest". The project aimed to quantify the ecological value of the Azorean forests, including carbon accumulation and to design and propose measures that could further enhance forest sustainability. For that, 90 forest plots were sampled on three Azores islands - São Miguel, Terceira and Pico - equally distributed into natural forest, exotic woodland and production forest. The aim of this report is to further expand knowledge on biodiversity trends enclosed in the different forest types present in the Azores, by providing a list of the occurrences of the 105 different vascular plant taxa together with a brief characterisation of their origin and life-form. We provide an inventory of indigenous and non-indigenous vascular plant taxa from 90 forest stands. A total of 105 taxa ...

Scientific Reports

Assessment of forest ecosystems and their services is seen as a key action for the advancement of... more Assessment of forest ecosystems and their services is seen as a key action for the advancement of biodiversity objectives, and to inform the development and implementation of related policies and planning. The Azorean forest is important for timber production, the protection of soil and water resources, and for its recreational and aesthetic value. However, its role in carbon accumulation has not been fully addressed. We assessed plant diversity, forest structure and carbon stocks in a gradient of three forest types (Natural Forest-NF; Exotic Woodland-EW and Production Forest-PF) in three of the Azores islands. We used biodiversity indices and found that NF harbored the highest plant diversity levels and PF the lowest. Diversity levels were lower for structural than for taxonomic data, particularly for PF. The highest tree carbon stock was found at EW in one of the islands, while PF consistently exhibited relatively high tree carbon stocks in the three islands. The largest soil carb...

Ecology and Evolution, 2020

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Nos Açores, o ... more A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Nos Açores, o incenso (Pittosporum undulatum), espécie nativa da Austrália, foi introduzido no arquipélago no século XIX, para a edificação de sebes em pomares de laranjeira. Durante os últimos 100 anos, o incenso dispersou por uma vasta gama de habitats, ocupando atualmente cerca 24.000 ha do total de 62.981 ha da cobertura florestal Açoreana. Presentemente, não existem recursos disponíveis para controlar a invasão. No entanto, tem estado a decorrer um projeto que tem como intuito valorizar o potencial da biomassa como um instrumento de gestão do incenso. Este projeto de doutoramento orientado pelos professores Luis Silva, Rui Elias e Mário Alves da Universidade dos Açores foi financiado pela NaturalReason Lda, empresa que se dedica a produção de pellets de madeira, um combustível sólido gerado a partir de biomassa florestal. […].info:eu-repo/semantics/publishedVersio

A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.[…] No arquipélago... more A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.[…] No arquipélago dos Açores, um terço das manchas florestais e dominado por incenso (Pittosporum undulatum), ameaçando os ecossistemas naturais, nomeadamente a vegetação nativa. No entanto, os bosques de exóticas também podem ter um enorme potencial de biomassa. No caso do incenso, a nossa equipa (CIBIO-Açores) tem vindo a realizar estudos no que se refere a possibilidade de valorização energética da sua biomassa, em conjunto com parceiros privados. O objetivo deste estudo, que fez parte da minha tese de doutoramento, foi o de avaliar a disponibilidade de biomassa da planta invasora lenhosa Pittosporum undulatum, devido ao seu baixo teor de cinzas e ao poder calorífico relativamente alto da sua biomassa, nas ilhas de São Miguel, Terceira e Graciosa, para determinar o seu potencial de valorização energética. Neste estudo, usamos diferentes abordagens de modelação em combinação com dados de inventário flo...

Assessment of forest ecosystems and their services is seen as a key action for the advancement of... more Assessment of forest ecosystems and their services is seen as a key action for the advancement of biodiversity objectives, and to inform the development and implementation of related policies and planning. We assessed biodiversity, structure and carbon stocks in a gradient of three forest types (Natural Forest-NF; Exotic Woodland-EW and Production Forest-PF) in three of the Azores islands. We used biodiversity indices and found that NF harbored the highest plant biodiversity levels and PF the lowest. Diversity levels were lower for structural than for taxonomic data, particularly for PF. The highest tree carbon stock was found at EW in one of the islands, while PF consistently exhibited relatively high tree carbon stocks in the three islands. The largest soil carbon stocks were found at EW, while leaf litter carbon stocks were higher at PF. We concluded that NF play a fundamental role as biodiversity hotspots but have lower relevance as carbon stocks. PFs provide economic assets and...

The use of biomass for energy production has shown a growing interest in recent years. Pittosporu... more The use of biomass for energy production has shown a growing interest in recent years. Pittosporum undulatum is a widespread invasive tree in the Azores archipelago with a considerable potential as an energy resource. Sustainable use of forest resources demands accurate and precise estimation of standing biomass but for the Azores only a few studies exist devoted to estimation of above-ground biomass (AGB). Here we used published allometric equations and developed new models for the estimation of P. undulatum total AGB in the exotic woodlands of the Azores. A total of 470 trees were sampled at 11 P. undulatum stands in Sao Miguel Island, and their total biomass and several dendrometric traits were recorded in the field. Several dendrometric variables were used as predictors for biomass: diameter at breast height, D; tree height,H; basal area, BA; canopy height, CH; canopy diameter, CD; canopy biovolume, BV; and number of branches at breast height, NB. For model comparison and evalua...

Forests

As in many archipelagos, the Azorean primary forest was largely cleared and replaced by secondary... more As in many archipelagos, the Azorean primary forest was largely cleared and replaced by secondary forest and grassland, the Azorean tree Laurus azorica (Seub.) Franco being one of the dominant trees in the remaining natural forests. Dendrochronological and dendrometric studies in the Azores mainly focused on non-indigenous trees, either used for timber (e.g., Cryptomeria japonica D. Don) or considered as invasive (Pittosporum undulatum Vent.). Therefore, this study aims to describe the growth ring anatomy of L. azorica, and to understand the relationship between dendrometric traits (e.g., trunk diameter at breast height; tree height), and the number of growth rings. Growth ring anatomy was accessed by wood anatomical preparation of microcore samples while tree age estimation was based on growth ring counts in wood cores taken at breast height and at base. A total of 145 trees were sampled, resulting in 262 increment cores, at six representative stands of laurel forest in São Miguel ...

Systematic Botany

Abstract The pollen fertility of F1 hybrids, ranging from progeny within natural populations to s... more Abstract The pollen fertility of F1 hybrids, ranging from progeny within natural populations to synthetic hybrids between species of Tolpis from three archipelagos in Macaronesia, was determined. Pollen fertility of F1 hybrids of inter-archipelago crosses from the Azores, Canaries, and Madeira were generally lower than crosses between populations or species in the same archipelagos. Lower pollen fertility was pronounced in hybrids between plants from the Canaries and the other archipelagos, which is concordant with a more distant phylogenetic relationship between the Canaries, and the Azores and Madeira. Lower average pollen fertility was seen between plants from different as compared to the same clades in the Canary Islands. However, low pollen fertilities were also detected between plants from some populations/species in the same archipelagos, and even among progeny of individual maternal plants. Some hybrids with reduced fertility had meiotic irregularities, suggesting chromosomal rearrangements; in other cases meiosis appeared normal. Results indicate that postzygotic isolating factors evolved subsequent to the divergence of Tolpis in the three archipelagos, but there are hybrid sterility factors among plants within each of the archipelagos, and even within some natural populations. Phylogenetic relationships in the Canary Islands indicate that divergence has occurred within the last million years. Present results implicate postzygotic factors as reproductive barriers facilitating population divergence and speciation in Macaronesian Tolpis.

International Journal of Forestry Research

Tree density is an important parameter affecting ecosystems functions and management decisions, w... more Tree density is an important parameter affecting ecosystems functions and management decisions, while tree distribution patterns affect sampling design.Pittosporum undulatumstands in the Azores are being targeted with a biomass valorization program, for which efficient tree density estimators are required. We comparedT-Square sampling, Point Centered Quarter Method (PCQM), andN-tree sampling with benchmark quadrat (QD) sampling in six 900 m2plots established atP. undulatumstands in São Miguel Island. A total of 15 estimators were tested using a data resampling approach. The estimated density range (344–5056 trees/ha) was found to agree with previous studies using PCQM only. Although with a tendency to underestimate tree density (in comparison with QD), overall,T-Square sampling appeared to be the most accurate and precise method, followed by PCQM. Tree distribution pattern was found to be slightly aggregated in 4 of the 6 stands. Considering (1) the low level of bias and high precis...

Forest Ecology and Management

Abstract Pittosporum undulatum Ventenat (Pittosporaceae) is an invasive tree of forests and woodl... more Abstract Pittosporum undulatum Ventenat (Pittosporaceae) is an invasive tree of forests and woodlands in several regions of the world. In the Azores archipelago it occupies about 30% of the forested areas and efforts to valorize its biomass are underway. Implementing sustainable forest management requires basic information on tree age and growth rate, yet this information was lacking. We used tree-ring analysis to obtain accurate age estimates and growth rates from a total of 982 live trees (1318 samples: 646 increment cores and 336 pairs of stem discs) that were sampled in Sao Miguel, Terceira and Graciosa islands. Pittosporum undulatum showed distinct annual growth rings with an increase in cell-wall thickness and a decrease in cell lumen of the Fibers, from early to latewood. We found trees with ages at base and at breast height ranging from 5/4 to 131/108 years, respectively. Samples taken at tree base and at breast height allowed to estimate a diameter growth rate of 0.38 cm.year−1, with an average of 8 years needed to attain breast height, and a rotation period of 26 years to reach the average diameter of 7 cm presently found at the stands. Allometric equations relating tree age and diameter at breast height, tree height, basal area and biomass were found to be significant. Among the models with lowest AIC, equations predicting tree age from diameter at breast height or from biomass showed the best fit (R2 = 0.65 and for R2 = 0.70, respectively). The developed methods and the obtained results can now be used to support management of biomass valorization projects but also to better understand invasion dynamics at conservation devoted areas.

Plant Systematics and Evolution, 2015

Ecology and Evolution, 2020

Genome‐wide genotyping and Bayesian inference method (BORICE) were employed to estimate outcrossi... more Genome‐wide genotyping and Bayesian inference method (BORICE) were employed to estimate outcrossing rates and paternity in two small plant populations of Tolpis succulenta (Asteraceae) on Graciosa island in the Azores. These two known extant populations of T. succulenta on Graciosa have recently evolved self‐compatibility. Despite the expectation that selfing would occur at an appreciable rate (self‐incompatible populations of the same species show low but nonzero selfing), high outcrossing was found in progeny arrays from maternal plants in both populations. This is inconsistent with an immediate transition to high selfing following the breakdown of a genetic incompatibility system. This finding is surprising given the small population sizes and the recent colonization of an island from self‐incompatible colonists of T. succulenta from another island in the Azores, and a potential paucity of pollinators, all factors selecting for selfing through reproductive assurance. The self‐com...

Biodiversity Data Journal, Aug 3, 2023

Plant Systematics and Evolution, 2015

Biodiversity Data Journal

Scientific Reports

Ecology and Evolution, 2020

Assessment of forest ecosystems and their services is seen as a key action for the advancement of... more Assessment of forest ecosystems and their services is seen as a key action for the advancement of biodiversity objectives, and to inform the development and implementation of related policies and planning. We assessed biodiversity, structure and carbon stocks in a gradient of three forest types (Natural Forest-NF; Exotic Woodland-EW and Production Forest-PF) in three of the Azores islands. We used biodiversity indices and found that NF harbored the highest plant biodiversity levels and PF the lowest. Diversity levels were lower for structural than for taxonomic data, particularly for PF. The highest tree carbon stock was found at EW in one of the islands, while PF consistently exhibited relatively high tree carbon stocks in the three islands. The largest soil carbon stocks were found at EW, while leaf litter carbon stocks were higher at PF. We concluded that NF play a fundamental role as biodiversity hotspots but have lower relevance as carbon stocks. PFs provide economic assets and...

Forests

Systematic Botany

International Journal of Forestry Research

Forest Ecology and Management

Plant Systematics and Evolution, 2015

Ecology and Evolution, 2020