Karin Santos | Swedish Museum of Natural History (original) (raw)
Papers by Karin Santos
Applied Vegetation Science, 2020
Question: We aimed to analyze how the topography, temperature and rainfall influence the floristi... more Question: We aimed to analyze how the topography, temperature and rainfall influence the floristic distribution in three different topographic areas and their surrounding vegetation. We addressed three main questions: (i) How is the distribution of species among the topographic areas? (ii) Which abiotic variable is driving this distribution? and (iii) What is the difference among the mountain forests and between mountain forests and the Caatinga vegetation? Location: The Maranguape mountain forest were divided into three topographic categories: windward (600-800 m, WMA), leeward (600-800 m, LMA) and top (above 800 m, TMA). We also considered another six areas of mountain forests and four Caatinga areas in Ceará State. Methods: We calculated different structural parameters and the floristic diversity of each category. A Principal Correspondence Analysis was performed to analyze the indirect ordination of forest sites by species abundance. A Canonical Correspondence Analysis was conducted to evaluate which variables were driving species distribution. We used non-metric multidimensional scaling distance and the average linkage method to investigate the similarity among mountain forests and Caatinga. Results: A total of 1,536 individuals belonging to 144 tree species distributed in 44 families and 93 genera were recorded. Myrtaceae, Fabaceae and Rubiaceae were the most species-rich families. Myrcia splendens had the highest importance value followed by Guapira nitida and Mollinedia ovata. The leeward slope showed the highest richness and diversity index, whereas the windward showed the highest density and the top showed the highest basal area. The ordination indicated a greater similarity between TMA and WMA than LMA. Conclusion: Our results suggest that temperature, precipitation and slope angle are the abiotic factors driving species distribution in Maranguape. Those mountains are heavily anthropized and continuously explored, therefore these outcomes will be useful for conservation and restoration purposes in the poorly known semiarid region of Northeast Brazil.
Rodriguésia, 2016
This article visits the history of Brazil-Sweden's partnership in botany and the contribution... more This article visits the history of Brazil-Sweden's partnership in botany and the contribution of Anders Fredrik Regnell and other botanical collectors to the knowledge of Brazilian flora. The importance of the herbarium of Stockholm (S) is widely recognized for its collections of Brazilian plants, one of the largest in the world. The majority of the collections from Brazil date from the period between the second half of nineteenth century and the beginning of the twentieth century. The main collectors of Brazilian flora from that phase, whose bulk of collections are in Stockholm are Anders Regnell, Gustaf Malme, Per Dusén, Carl Lindman and many others sponsored by the Regnellian fund. The herbarium also houses substantial collections of August Glaziou, a great contributor to the knowledge of the flora of state of Goiás, and Adolf Ducke, pioneer in the taxonomy of Amazonian tree species. The cooperation between Brazil and Sweden is currently being renewed through Rio de Janeiro B...
Plant Ecology, 2016
Intense competition with lianas (wood climbers) can limit tree growth, reproduction, and survival... more Intense competition with lianas (wood climbers) can limit tree growth, reproduction, and survival. However, the negative effects of liana loads on tree allometry have not yet been addressed. We investigated the hypothesis that liana loading on tree crown alters tree's allometry, expressed through slenderness (height-diameter ratio). The relationship between trunk slenderness and percentage of tree crown covered by lianas was investigated for 12 tree species from 10 fragments of the Semideciduous Seasonal Forest in Southeastern Brazil. We also tested whether the relationship between slenderness and wood density differ between trees without lianas and trees heavily infested. Liana loads significantly altered tree allometry by decreasing slenderness, even when lianas covered less than 25% of tree crown. Heavywood species decreased their trunk slenderness in a greater ratio than light-wood species. Our findings indicate that liana infestation shifts tree allometry, and these effects are stronger on heavy-wood tree species.
Biota Neotropica, 2006
Currently, forest fragmentation is said to be related to deleterious effects on biotic communitie... more Currently, forest fragmentation is said to be related to deleterious effects on biotic communities. Such effects would be: species loss, changes in species composition and structure, increasing rates of damaged or dead trees and canopy openness. The extent of these alterations has been mainly associated to the size of the forest fragments. It has been said that small fragments often have fewer species recorded for the same effort of observation than large ones. The main purpose of this work was to verify if there is a relationship between floristic composition, structure and some qualitative aspects (canopy quality and openness) and fragment size. Eleven semideciduous forest fragments of several sizes were chosen at the Environmental Protection Area of Campinas County, Southeastern Brazil. Ten of these fragments are smaller than 100ha and one is 244.9ha. The fragments <100ha were grouped into three classes: small (10-15ha), medium (16-25ha) and large (40-65ha). In each forest fragment, using the point-centered quarter method, 125 sampling points were surveyed, including only stems bigger than 10cm diameter at breast height. Each five hundred stems sample was compared with samples gathered by the same way at three distinct locations at the 244.9ha fragment. A total of 6500 individuals were sampled, distributed in 248 species and 55 families. The number of species for each sample of 500 individuals ranged from 47 to 110 species, however most fragments have shown about 100 species, despite its total area. Two samples showed a much lower richness: one of them, containing 47 species, was a small fragment, and the other, containing 65 species, was a large one. Most fragments have shown about 40% of the total species sampled, indicating a great contribution to the regional species pool. 25% (65 species) are rarely found at other floristic surveys made at São Paulo State, and 13.6% of the species were found for the first time at Campinas County. In addition, almost 22% of species have occurred in just one fragment, showing their importance for conservation purposes. The diversity indices and estimated richness didn't differ among fragments. Many species were numerous in only one or two fragments, but in all fragments occurred an abundance concentration, where few species showed great dominance. Stems density was 40% smaller in large fragments and in the 244.9ha fragment's samples, but there was no relation between fragment size and density, as occurred with other structural
Global Ecology and Biogeography, 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.
Biota Neotropica, 2006
O processo de fragmentação de florestas tem sido freqüentemente relacionado a efeitos deletérios ... more O processo de fragmentação de florestas tem sido freqüentemente relacionado a efeitos deletérios sobre as comunidades bióticas. Tais efeitos seriam: perda de espécies, alterações na estrutura e composição da vegetação e aumento da proporção de árvores mortas ou danificadas. A magnitude de tais alterações tem sido associada principalmente ao tamanho dos remanescentes florestais. Afirma-se que fragmentos pequenos apresentariam um número menor de espécies, pois muitas não sobreviveriam em áreas reduzidas. Além disso, florestas pequenas estariam mais expostas ao efeito de borda, devido sua maior razão borda:interior. O objetivo deste trabalho foi verificar se as variações de composição florística, riqueza, diversidade, estrutura florestal e aspectos qualitativos (qualidade e porcentagem de abertura de dossel) entre fragmentos de mata poderia estar associada à área total dos mesmos. Na região da Área de Proteção Ambiental do município de Campinas, SP, foram escolhidos dez fragmentos com ...
Biological Conservation, 2007
Bar. Brazilian Administration Review, 2009
In this study we evaluated floristic composition patterns of communities of climbers within ten i... more In this study we evaluated floristic composition patterns of communities of climbers within ten inventories carried out in semideciduous forest fragments of southeastern Brazil. One of the inventories is original, being carried out for the present study in Ribeirão Cachoeira forest, Campinas, São Paulo State, Southeastern Brazil. This inventory was then pooled together to other nine climbers' inventories made in other forests of Southeastern Brazil to form a data base, which was examined regarding species richness, similarity, species distribution and climbing methods. The total number of species obtained was 355, belonging to 145 genera and 43 families. The ten most diverse families Bignoniaceae (45 species), Fabaceae (42), Malpighiaceae (36), Asteraceae (31), Apocynaceae (29), Sapindaceae (28), Convolvulaceae (21), Cucurbitaceae (14), Passifloraceae (10), and Euphorbiaceae (8) contributed to 74.4% of the total number of species recorded. The commonest climbing method in the studied sites was main stem or branch twining, accounting for 178 species or 50.1% of the total, the second commonest was tendril climbing (121 species, 34.1%), and the least, scrambling (56 species, 15.8%). We found a high percentage of exclusive species i.e., those occurring in only one forest site, which accounted for 49.3% of the total recorded. The mean similarity among forest sites (30%) may be considered low. The climbing species contribution to the total wood plant richness recorded on the forests sites was very high in some of the sites (up to 52.5%). These results indicated the importance of climber communities to plant diversity for semideciduous forests in Southeastern Brazil, enhancing the regional diversity and the conservation value of these forest remnants.
Acta Botanica Brasilica, 2003
This study investigates the influence of fragment size on tree species composition, species richn... more This study investigates the influence of fragment size on tree species composition, species richness and on individual groups of species within 11 semideciduous forest fragments in southeastern Brazil. We compared same-sized samples of 500 trees from 10 fragments <100 ha, allocated to three size categories, with three 500-tree samples collected in different areas within a large forest, used as a reference forest. The variation in species richness, in the proportion of species/individuals in dispersal modes, and in the proportion of rare species was not related to fragment size. Nonetheless, comparisons between the mean values of these variables of each fragment size categories, using 95% confidence intervals, showed a wider range of variation within the category of small-sized fragments than in the other size categories. NMS ordination plot also suggested the absence of a relationship between fragment area and tree species composition. However, multiple regressions using the scores from the NMS ordination as response variables, and area and disturbance intensities as predictor variables, suggested that the interaction of area and disturbance might be a good predictor of species composition. Pre-existing environmental heterogeneity and geographical proximity also appeared to play a role in the variations of forest composition among the fragments studied. Our results demonstrated the high conservation value of small forest fragments.
Applied Vegetation Science, 2020
Question: We aimed to analyze how the topography, temperature and rainfall influence the floristi... more Question: We aimed to analyze how the topography, temperature and rainfall influence the floristic distribution in three different topographic areas and their surrounding vegetation. We addressed three main questions: (i) How is the distribution of species among the topographic areas? (ii) Which abiotic variable is driving this distribution? and (iii) What is the difference among the mountain forests and between mountain forests and the Caatinga vegetation? Location: The Maranguape mountain forest were divided into three topographic categories: windward (600-800 m, WMA), leeward (600-800 m, LMA) and top (above 800 m, TMA). We also considered another six areas of mountain forests and four Caatinga areas in Ceará State. Methods: We calculated different structural parameters and the floristic diversity of each category. A Principal Correspondence Analysis was performed to analyze the indirect ordination of forest sites by species abundance. A Canonical Correspondence Analysis was conducted to evaluate which variables were driving species distribution. We used non-metric multidimensional scaling distance and the average linkage method to investigate the similarity among mountain forests and Caatinga. Results: A total of 1,536 individuals belonging to 144 tree species distributed in 44 families and 93 genera were recorded. Myrtaceae, Fabaceae and Rubiaceae were the most species-rich families. Myrcia splendens had the highest importance value followed by Guapira nitida and Mollinedia ovata. The leeward slope showed the highest richness and diversity index, whereas the windward showed the highest density and the top showed the highest basal area. The ordination indicated a greater similarity between TMA and WMA than LMA. Conclusion: Our results suggest that temperature, precipitation and slope angle are the abiotic factors driving species distribution in Maranguape. Those mountains are heavily anthropized and continuously explored, therefore these outcomes will be useful for conservation and restoration purposes in the poorly known semiarid region of Northeast Brazil.
Rodriguésia, 2016
This article visits the history of Brazil-Sweden's partnership in botany and the contribution... more This article visits the history of Brazil-Sweden's partnership in botany and the contribution of Anders Fredrik Regnell and other botanical collectors to the knowledge of Brazilian flora. The importance of the herbarium of Stockholm (S) is widely recognized for its collections of Brazilian plants, one of the largest in the world. The majority of the collections from Brazil date from the period between the second half of nineteenth century and the beginning of the twentieth century. The main collectors of Brazilian flora from that phase, whose bulk of collections are in Stockholm are Anders Regnell, Gustaf Malme, Per Dusén, Carl Lindman and many others sponsored by the Regnellian fund. The herbarium also houses substantial collections of August Glaziou, a great contributor to the knowledge of the flora of state of Goiás, and Adolf Ducke, pioneer in the taxonomy of Amazonian tree species. The cooperation between Brazil and Sweden is currently being renewed through Rio de Janeiro B...
Plant Ecology, 2016
Intense competition with lianas (wood climbers) can limit tree growth, reproduction, and survival... more Intense competition with lianas (wood climbers) can limit tree growth, reproduction, and survival. However, the negative effects of liana loads on tree allometry have not yet been addressed. We investigated the hypothesis that liana loading on tree crown alters tree's allometry, expressed through slenderness (height-diameter ratio). The relationship between trunk slenderness and percentage of tree crown covered by lianas was investigated for 12 tree species from 10 fragments of the Semideciduous Seasonal Forest in Southeastern Brazil. We also tested whether the relationship between slenderness and wood density differ between trees without lianas and trees heavily infested. Liana loads significantly altered tree allometry by decreasing slenderness, even when lianas covered less than 25% of tree crown. Heavywood species decreased their trunk slenderness in a greater ratio than light-wood species. Our findings indicate that liana infestation shifts tree allometry, and these effects are stronger on heavy-wood tree species.
Biota Neotropica, 2006
Currently, forest fragmentation is said to be related to deleterious effects on biotic communitie... more Currently, forest fragmentation is said to be related to deleterious effects on biotic communities. Such effects would be: species loss, changes in species composition and structure, increasing rates of damaged or dead trees and canopy openness. The extent of these alterations has been mainly associated to the size of the forest fragments. It has been said that small fragments often have fewer species recorded for the same effort of observation than large ones. The main purpose of this work was to verify if there is a relationship between floristic composition, structure and some qualitative aspects (canopy quality and openness) and fragment size. Eleven semideciduous forest fragments of several sizes were chosen at the Environmental Protection Area of Campinas County, Southeastern Brazil. Ten of these fragments are smaller than 100ha and one is 244.9ha. The fragments <100ha were grouped into three classes: small (10-15ha), medium (16-25ha) and large (40-65ha). In each forest fragment, using the point-centered quarter method, 125 sampling points were surveyed, including only stems bigger than 10cm diameter at breast height. Each five hundred stems sample was compared with samples gathered by the same way at three distinct locations at the 244.9ha fragment. A total of 6500 individuals were sampled, distributed in 248 species and 55 families. The number of species for each sample of 500 individuals ranged from 47 to 110 species, however most fragments have shown about 100 species, despite its total area. Two samples showed a much lower richness: one of them, containing 47 species, was a small fragment, and the other, containing 65 species, was a large one. Most fragments have shown about 40% of the total species sampled, indicating a great contribution to the regional species pool. 25% (65 species) are rarely found at other floristic surveys made at São Paulo State, and 13.6% of the species were found for the first time at Campinas County. In addition, almost 22% of species have occurred in just one fragment, showing their importance for conservation purposes. The diversity indices and estimated richness didn't differ among fragments. Many species were numerous in only one or two fragments, but in all fragments occurred an abundance concentration, where few species showed great dominance. Stems density was 40% smaller in large fragments and in the 244.9ha fragment's samples, but there was no relation between fragment size and density, as occurred with other structural
Global Ecology and Biogeography, 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.
Biota Neotropica, 2006
O processo de fragmentação de florestas tem sido freqüentemente relacionado a efeitos deletérios ... more O processo de fragmentação de florestas tem sido freqüentemente relacionado a efeitos deletérios sobre as comunidades bióticas. Tais efeitos seriam: perda de espécies, alterações na estrutura e composição da vegetação e aumento da proporção de árvores mortas ou danificadas. A magnitude de tais alterações tem sido associada principalmente ao tamanho dos remanescentes florestais. Afirma-se que fragmentos pequenos apresentariam um número menor de espécies, pois muitas não sobreviveriam em áreas reduzidas. Além disso, florestas pequenas estariam mais expostas ao efeito de borda, devido sua maior razão borda:interior. O objetivo deste trabalho foi verificar se as variações de composição florística, riqueza, diversidade, estrutura florestal e aspectos qualitativos (qualidade e porcentagem de abertura de dossel) entre fragmentos de mata poderia estar associada à área total dos mesmos. Na região da Área de Proteção Ambiental do município de Campinas, SP, foram escolhidos dez fragmentos com ...
Biological Conservation, 2007
Bar. Brazilian Administration Review, 2009
In this study we evaluated floristic composition patterns of communities of climbers within ten i... more In this study we evaluated floristic composition patterns of communities of climbers within ten inventories carried out in semideciduous forest fragments of southeastern Brazil. One of the inventories is original, being carried out for the present study in Ribeirão Cachoeira forest, Campinas, São Paulo State, Southeastern Brazil. This inventory was then pooled together to other nine climbers' inventories made in other forests of Southeastern Brazil to form a data base, which was examined regarding species richness, similarity, species distribution and climbing methods. The total number of species obtained was 355, belonging to 145 genera and 43 families. The ten most diverse families Bignoniaceae (45 species), Fabaceae (42), Malpighiaceae (36), Asteraceae (31), Apocynaceae (29), Sapindaceae (28), Convolvulaceae (21), Cucurbitaceae (14), Passifloraceae (10), and Euphorbiaceae (8) contributed to 74.4% of the total number of species recorded. The commonest climbing method in the studied sites was main stem or branch twining, accounting for 178 species or 50.1% of the total, the second commonest was tendril climbing (121 species, 34.1%), and the least, scrambling (56 species, 15.8%). We found a high percentage of exclusive species i.e., those occurring in only one forest site, which accounted for 49.3% of the total recorded. The mean similarity among forest sites (30%) may be considered low. The climbing species contribution to the total wood plant richness recorded on the forests sites was very high in some of the sites (up to 52.5%). These results indicated the importance of climber communities to plant diversity for semideciduous forests in Southeastern Brazil, enhancing the regional diversity and the conservation value of these forest remnants.
Acta Botanica Brasilica, 2003
This study investigates the influence of fragment size on tree species composition, species richn... more This study investigates the influence of fragment size on tree species composition, species richness and on individual groups of species within 11 semideciduous forest fragments in southeastern Brazil. We compared same-sized samples of 500 trees from 10 fragments <100 ha, allocated to three size categories, with three 500-tree samples collected in different areas within a large forest, used as a reference forest. The variation in species richness, in the proportion of species/individuals in dispersal modes, and in the proportion of rare species was not related to fragment size. Nonetheless, comparisons between the mean values of these variables of each fragment size categories, using 95% confidence intervals, showed a wider range of variation within the category of small-sized fragments than in the other size categories. NMS ordination plot also suggested the absence of a relationship between fragment area and tree species composition. However, multiple regressions using the scores from the NMS ordination as response variables, and area and disturbance intensities as predictor variables, suggested that the interaction of area and disturbance might be a good predictor of species composition. Pre-existing environmental heterogeneity and geographical proximity also appeared to play a role in the variations of forest composition among the fragments studied. Our results demonstrated the high conservation value of small forest fragments.