Paivi Merila | Natural Resources Institute Finland (original) (raw)
Papers by Paivi Merila
Ecosystems
Carbon (C) sequestrated in the boreal forest ecosystems plays an important role in climate regula... more Carbon (C) sequestrated in the boreal forest ecosystems plays an important role in climate regulation. This study’s objectives were to quantify the differences in the components of the forest C cycle along a 1000 km latitudinal gradient within the boreal region and between dominant coniferous species in Fennoscandia. The study included seven xeric–sub-xeric and eight mesic–herb-rich heath forests dominated by Scots pine and Norway spruce, respectively. The total site carbon stock (CS) ranged from 81 to 260 Mg ha−1. The largest ecosystem component CSs were tree stems, mineral soil, and humus layer, representing 30 ± 2%, 28 ± 2%, and 13 ± 1% of total CS, respectively. On average, the spruce sites had 40% more C than the pine sites, and CS stored in most compartments was higher on spruce than on pine sites. As exceptions, understorey vegetation and litter layer had a larger CS on pine than on spruce sites. The northern sites had an average of 58% less C than the southern sites. Humus l...
Applied Vegetation Science, Oct 1, 2022
All material supplied via Jukuri is protected by copyright and other intellectual property rights... more All material supplied via Jukuri is protected by copyright and other intellectual property rights. Duplication or sale, in electronic or print form, of any part of the repository collections is prohibited. Making electronic or print copies of the material is permitted only for your own personal use or for educational purposes. For other purposes, this article may be used in accordance with the publisher's terms. There may be differences between this version and the publisher's version. You are advised to cite the publisher's version. This is an electronic reprint of the original article. This reprint may differ from the original in pagination and typographic detail.
Annals of forest science, Oct 1, 2015
Nature Climate Change
In the version of this article initially published, a variable was mistakenly reversed in the pre... more In the version of this article initially published, a variable was mistakenly reversed in the presentation data for the center row of Extended Data Figure 1, inverting the yellow-purple color gradient. The image has been corrected in the HTML and PDF versions of the article.
Forest Ecology and Management, 2021
This presentation aims at promoting a more comprehensive, ecologically-based approach to the stud... more This presentation aims at promoting a more comprehensive, ecologically-based approach to the study the effects of air pollution on forests. Most studies in this field were developed from a relatively narrow perspective. The role of traditional ecological driving forces (availability of resources, competition for resources, climate and weather fluctuations), interactions with biotic and abiotic factors, the inherent ecosystem dynamics and processes, and management history were seldom (if ever) accounted for. The wealth of studies dealing with air pollution effects on forests focussed on the physiological response of plants to a number of pollutants. Often, even the collection of data on e.g. insect attacks on trees is considered not relevant because believed to be not important in identifying air pollution effects. This is a clear ecological nonsense, as the entire suite of biotic and abiotic factors is related to forest health and productivity and exert a great role on forest diversity, ultimately affecting forest response. Ignoring the role of biotic factors (e.g. insects) may lead to a substantial misinterpretation of the role of abiotic factors (e.g. air pollution). The same applies to the role of management: age, thinning, density and competition can affect health, productivity and diversity, and offset or exacerbate the role of environmental drivers. The debate about the effect of tropospheric ozone on forests is a good example of this and will be used as an example in the presentation. Despite the above ideas are well established in forest ecology, present Critical Levels (CLs) to protect forest vegetation from ozone are set on the basis of experiments that omit to consider all the most important drivers of forest health, productivity and diversity. Therefore, their applicability in the real world of forest ecosystems is questionable.
Forest Ecology and Management, 2021
Boreal forests are rich in non-timber forest products from plants: wild berries and herbs used co... more Boreal forests are rich in non-timber forest products from plants: wild berries and herbs used commercially or by households as food, medicine, decoration, or raw material. Approximately two hundred wild plant species have been documented for their nutritional uses in Finland, and many of these species occur in forests. However, the provisioning of edible plants by managed forests has received little attention, despite the fact that forest vegetation is altered by forest management practices. In this study, we use nationwide forest vegetation and tree stand data consisting of a total of 1,778 sample plots to quantify the richness and abundance of edible wild plants in Finnish forests. Responses of edible species richness, abundance, and composition to stand characteristics such as site type, tree species composition, stand density, and management history are analyzed with regression models, NMDS ordination, and diagnostic species analysis, for forests on mineral soils and on peatlands separately. A total of 68 edible wild plant species occur in our dataset, with their occurrence and abundance varying between species and between sites. Our results indicate that habitat characteristics, namely site fertility and stand density, are the strongest determinants of overall edible plant provisioning. The richness of edible species as well as their total abundance were lower in less fertile site types and in denser stands. Recent timber harvesting and plantation as opposed to natural regeneration had a negative effect on edible species abundance in mineral soil forests. Several edible plant species confined to the richest site types accounted for the increase in species richness, while different forest management practices had generally none or a negligible number of diagnostic species. We conclude that a large and diverse set of edible wild plants occurs in Finnish forests, and the effects of stand characteristics and management on overall edible plant richness and abundance may be muddled by opposite species-level responses. Edible plant provisioning should be further analyzed at the level of smaller species groups or individual species to reveal the opportunities to support it in managed forests.
Tampere muutoksen tuulissa Katariina Rauhala 8 Yhdyskuntalietteiden sisältämien haitallisten orga... more Tampere muutoksen tuulissa Katariina Rauhala 8 Yhdyskuntalietteiden sisältämien haitallisten orgaanisten yhdisteiden esiintyminen ja käyttäytyminen ympäristössä Lauri Äystö 9 Sessio I: Maaperä kiertotalouden perustana
Northern ecosystems under changing environment Assessing one-way coupling between a limited area ... more Northern ecosystems under changing environment Assessing one-way coupling between a limited area climate model and a land surface scheme T. Markkanen, T.
En Europe, la productivité des forêts a augmenté durant les dernières décennies suite à l’effet c... more En Europe, la productivité des forêts a augmenté durant les dernières décennies suite à l’effet combiné de la concentration croissante en CO2 dans l’atmosphère et des dépôts atmosphériques d’azote. Les dépôts d’azote étant restés élevés dans différentes régions d’Europe et la concentration en CO2 dans l’atmosphère continuant de s’accroître, cette productivité pourrait encore augmenter sauf si elle devient limitée par la disponibilité d’autres ressources, notamment les nutriments. Les objectifs de cette étude étaient de décrire le statut nutritionnel foliaire des principales essences forestières en Europe (hêtre commun, chênes sessile et pédonculé, épicéa commun, pin sylvestre, sapin pectiné), d’identifier les nutriments limitants pour la croissance pour chacune de ces essences et de détecter les évolutions temporelles de la nutrition foliaire. Elle s’est basée sur les données d’analyses foliaires collectées entre 1992 et 2009 dans les placettes de suivi des écosystèmes forestiers de niveau II du programme international concerté sur les forêts (PIC Forêts). Il s’agit d’un jeu de données unique qui couvre l’entièreté de l’Europe sur deux décennies et qui a été produit selon des méthodes harmonisées entre les différents pays. Le niveau de nutrition en azote est généralement bon (suboptimal à optimal) pour les feuillus, mais sous le seuil de déficit pour environ la moitié des placettes résineuses. En revanche, une déficience en phosphore est constatée pour une part notable des placettes de chaque essence (de 22 à 74 %). Toutes les essences sont aussi affectées par des déficiences en cations basiques (calcium, magnésium, potassium) mais dans une moindre proportion de leurs placettes (de 5 à 40 %). L’analyse des tendances a permis de mettre en évidence une augmentation significative de la masse des feuilles ou des aiguilles chez le hêtre et l’épicéa commun. Au niveau des teneurs foliaires, la grande majorité des évolutions détectées sont des tendances à la baisse (20 sur 22). Parmi les évolutions les plus préoccupantes, on note une dégradation nette de la nutrition en phosphore pour la plupart des essences, ce qui confirme le signal mis en évidence précédemment à l’échelle des placettes de France, de Wallonie et du Luxembourg (Jonard et al., 2009). Les teneurs foliaires en azote, soufre et potassium diminuent également significativement pour certaines essences. En ce qui concerne le calcium et le magnésium, des tendances à la baisse sont observées pour les essences feuillues et à la hausse pour les essences résineuse
Long-term changes in soil carbon stocks after afforestation of cropland in Denmark P.1.26 Florenc... more Long-term changes in soil carbon stocks after afforestation of cropland in Denmark P.1.26 Florence Tauc et al. Microtopography and rainfall exclusion effects on sugar maple and bitternut hickory fine roots vertical distribution
Ecosystems
Carbon (C) sequestrated in the boreal forest ecosystems plays an important role in climate regula... more Carbon (C) sequestrated in the boreal forest ecosystems plays an important role in climate regulation. This study’s objectives were to quantify the differences in the components of the forest C cycle along a 1000 km latitudinal gradient within the boreal region and between dominant coniferous species in Fennoscandia. The study included seven xeric–sub-xeric and eight mesic–herb-rich heath forests dominated by Scots pine and Norway spruce, respectively. The total site carbon stock (CS) ranged from 81 to 260 Mg ha−1. The largest ecosystem component CSs were tree stems, mineral soil, and humus layer, representing 30 ± 2%, 28 ± 2%, and 13 ± 1% of total CS, respectively. On average, the spruce sites had 40% more C than the pine sites, and CS stored in most compartments was higher on spruce than on pine sites. As exceptions, understorey vegetation and litter layer had a larger CS on pine than on spruce sites. The northern sites had an average of 58% less C than the southern sites. Humus l...
Applied Vegetation Science, Oct 1, 2022
All material supplied via Jukuri is protected by copyright and other intellectual property rights... more All material supplied via Jukuri is protected by copyright and other intellectual property rights. Duplication or sale, in electronic or print form, of any part of the repository collections is prohibited. Making electronic or print copies of the material is permitted only for your own personal use or for educational purposes. For other purposes, this article may be used in accordance with the publisher's terms. There may be differences between this version and the publisher's version. You are advised to cite the publisher's version. This is an electronic reprint of the original article. This reprint may differ from the original in pagination and typographic detail.
Annals of forest science, Oct 1, 2015
Nature Climate Change
In the version of this article initially published, a variable was mistakenly reversed in the pre... more In the version of this article initially published, a variable was mistakenly reversed in the presentation data for the center row of Extended Data Figure 1, inverting the yellow-purple color gradient. The image has been corrected in the HTML and PDF versions of the article.
Forest Ecology and Management, 2021
This presentation aims at promoting a more comprehensive, ecologically-based approach to the stud... more This presentation aims at promoting a more comprehensive, ecologically-based approach to the study the effects of air pollution on forests. Most studies in this field were developed from a relatively narrow perspective. The role of traditional ecological driving forces (availability of resources, competition for resources, climate and weather fluctuations), interactions with biotic and abiotic factors, the inherent ecosystem dynamics and processes, and management history were seldom (if ever) accounted for. The wealth of studies dealing with air pollution effects on forests focussed on the physiological response of plants to a number of pollutants. Often, even the collection of data on e.g. insect attacks on trees is considered not relevant because believed to be not important in identifying air pollution effects. This is a clear ecological nonsense, as the entire suite of biotic and abiotic factors is related to forest health and productivity and exert a great role on forest diversity, ultimately affecting forest response. Ignoring the role of biotic factors (e.g. insects) may lead to a substantial misinterpretation of the role of abiotic factors (e.g. air pollution). The same applies to the role of management: age, thinning, density and competition can affect health, productivity and diversity, and offset or exacerbate the role of environmental drivers. The debate about the effect of tropospheric ozone on forests is a good example of this and will be used as an example in the presentation. Despite the above ideas are well established in forest ecology, present Critical Levels (CLs) to protect forest vegetation from ozone are set on the basis of experiments that omit to consider all the most important drivers of forest health, productivity and diversity. Therefore, their applicability in the real world of forest ecosystems is questionable.
Forest Ecology and Management, 2021
Boreal forests are rich in non-timber forest products from plants: wild berries and herbs used co... more Boreal forests are rich in non-timber forest products from plants: wild berries and herbs used commercially or by households as food, medicine, decoration, or raw material. Approximately two hundred wild plant species have been documented for their nutritional uses in Finland, and many of these species occur in forests. However, the provisioning of edible plants by managed forests has received little attention, despite the fact that forest vegetation is altered by forest management practices. In this study, we use nationwide forest vegetation and tree stand data consisting of a total of 1,778 sample plots to quantify the richness and abundance of edible wild plants in Finnish forests. Responses of edible species richness, abundance, and composition to stand characteristics such as site type, tree species composition, stand density, and management history are analyzed with regression models, NMDS ordination, and diagnostic species analysis, for forests on mineral soils and on peatlands separately. A total of 68 edible wild plant species occur in our dataset, with their occurrence and abundance varying between species and between sites. Our results indicate that habitat characteristics, namely site fertility and stand density, are the strongest determinants of overall edible plant provisioning. The richness of edible species as well as their total abundance were lower in less fertile site types and in denser stands. Recent timber harvesting and plantation as opposed to natural regeneration had a negative effect on edible species abundance in mineral soil forests. Several edible plant species confined to the richest site types accounted for the increase in species richness, while different forest management practices had generally none or a negligible number of diagnostic species. We conclude that a large and diverse set of edible wild plants occurs in Finnish forests, and the effects of stand characteristics and management on overall edible plant richness and abundance may be muddled by opposite species-level responses. Edible plant provisioning should be further analyzed at the level of smaller species groups or individual species to reveal the opportunities to support it in managed forests.
Tampere muutoksen tuulissa Katariina Rauhala 8 Yhdyskuntalietteiden sisältämien haitallisten orga... more Tampere muutoksen tuulissa Katariina Rauhala 8 Yhdyskuntalietteiden sisältämien haitallisten orgaanisten yhdisteiden esiintyminen ja käyttäytyminen ympäristössä Lauri Äystö 9 Sessio I: Maaperä kiertotalouden perustana
Northern ecosystems under changing environment Assessing one-way coupling between a limited area ... more Northern ecosystems under changing environment Assessing one-way coupling between a limited area climate model and a land surface scheme T. Markkanen, T.
En Europe, la productivité des forêts a augmenté durant les dernières décennies suite à l’effet c... more En Europe, la productivité des forêts a augmenté durant les dernières décennies suite à l’effet combiné de la concentration croissante en CO2 dans l’atmosphère et des dépôts atmosphériques d’azote. Les dépôts d’azote étant restés élevés dans différentes régions d’Europe et la concentration en CO2 dans l’atmosphère continuant de s’accroître, cette productivité pourrait encore augmenter sauf si elle devient limitée par la disponibilité d’autres ressources, notamment les nutriments. Les objectifs de cette étude étaient de décrire le statut nutritionnel foliaire des principales essences forestières en Europe (hêtre commun, chênes sessile et pédonculé, épicéa commun, pin sylvestre, sapin pectiné), d’identifier les nutriments limitants pour la croissance pour chacune de ces essences et de détecter les évolutions temporelles de la nutrition foliaire. Elle s’est basée sur les données d’analyses foliaires collectées entre 1992 et 2009 dans les placettes de suivi des écosystèmes forestiers de niveau II du programme international concerté sur les forêts (PIC Forêts). Il s’agit d’un jeu de données unique qui couvre l’entièreté de l’Europe sur deux décennies et qui a été produit selon des méthodes harmonisées entre les différents pays. Le niveau de nutrition en azote est généralement bon (suboptimal à optimal) pour les feuillus, mais sous le seuil de déficit pour environ la moitié des placettes résineuses. En revanche, une déficience en phosphore est constatée pour une part notable des placettes de chaque essence (de 22 à 74 %). Toutes les essences sont aussi affectées par des déficiences en cations basiques (calcium, magnésium, potassium) mais dans une moindre proportion de leurs placettes (de 5 à 40 %). L’analyse des tendances a permis de mettre en évidence une augmentation significative de la masse des feuilles ou des aiguilles chez le hêtre et l’épicéa commun. Au niveau des teneurs foliaires, la grande majorité des évolutions détectées sont des tendances à la baisse (20 sur 22). Parmi les évolutions les plus préoccupantes, on note une dégradation nette de la nutrition en phosphore pour la plupart des essences, ce qui confirme le signal mis en évidence précédemment à l’échelle des placettes de France, de Wallonie et du Luxembourg (Jonard et al., 2009). Les teneurs foliaires en azote, soufre et potassium diminuent également significativement pour certaines essences. En ce qui concerne le calcium et le magnésium, des tendances à la baisse sont observées pour les essences feuillues et à la hausse pour les essences résineuse
Long-term changes in soil carbon stocks after afforestation of cropland in Denmark P.1.26 Florenc... more Long-term changes in soil carbon stocks after afforestation of cropland in Denmark P.1.26 Florence Tauc et al. Microtopography and rainfall exclusion effects on sugar maple and bitternut hickory fine roots vertical distribution