As they are not only the home of many threatened species, but also one of the main actors in the global carbon cycle, peatlands are highly valuable ecosystems. Human disturbance, in particular drainage for forestry and agriculture, has substantially changed the state of the world’s peatlands and will continue to do so. Lowering the water table by drainage has many hydrological and biological effects, including an increased growth of trees and shrubs as well as reduced growth of the key peat moss genus Sphagnum, leading to peat degradation and release of carbon dioxide. The effects of drainage are sometimes used as predictions for how peatlands will respond to climate change, and undrained mires are thus expected to become more like drained ones in the future. The accuracy of that assumption has, to my knowledge, not been tested on a large scale. Here, I use data from two Swedish national monitoring programs to analyze how the vegetation on drained and undrained mires has changed in recent decades. The results showed an increased tree growth but a decreased establishment of new trees on both drained and undrained mires, implying that contrary to common belief there is no current large-scale afforestation of open mires in Sweden. Sphagnum had, surprisingly, increased on both drained and undrained mires, while other functional groups showed varying results. The tree growth rate was faster on drained mires, but in most other analyses the response to time did not differ depending on drainage regime. Thereby, this study found limited support for the hypothesis that undrained mires are becoming more like drained mires with climate change.

Abstract Mechanical harvesting of peat changes the original mire ecosystem completely, and without active measures these areas may remain non-vegetated even for decades. Afforestation is one of the most popular after-use options for cut-away peatlands in Finland since it has both economic and aesthetic values. Recycling of wood-ash as a fertilizer has been studied extensively in peatlands drained for forestry. Wood-ash is reported to promote tree growth in these areas without any significant negative impact to the environment and could, therefore, be a suitable option also on cut-away peatlands. However, the environmental effects of ash-fertilization on cut-away areas and on ground vegetation are not fully understood. The impact of wood- and peat-ash application on the early establishment of ground vegetation and downy birch (Betula pubescens) seedlings and on post-fertilization element concentrations in plants and peat substrate were studied in a cut-away peatland. Six treatments of wood-ash, peat-ash, biotite or Forest PK-fertilizer were replicated in three blocks in different mixtures and quantities corresponding to 50 kg ha-1 of phosphorus. All the fertilizers accelerated the revegetation of the bare peat surface significantly, whereas the establishment of plants in the unfertilized area was non-existent even several years after the peat harvesting had ceased. The most striking difference between the wood- and peat-ash-fertilizers and the commercial Forest PK-fertilizer was the extensive coverage of fire-loving moss species in all the areas where ash was spread. Wood- and peat-ash application also accelerated the germination and early establishment of downy birch seedlings more efficiently than the PK-fertilizer. Ground vegetation proved to be highly important in increasing the early biomass production and carbon sequestration on ash-fertilized cut-away peatland. In addition, the below-ground biomass was equal to the above-ground biomass, or even greater. Both wood- and peat-ash fertilization ensured an adequate level of nutrients for the early establishment of ground vegetation and birch seedlings in a cut-away peatland. The mosses and herbaceous plants proved to have a major role in retaining the nutrients and heavy metals that otherwise might have leached away from the ash-fertilized cut-away site during the early stages of the afforestation. Although both wood- and peat-ash proved to be suitable for the initial fertilization of afforested cut-away peatlands, a later application of nutrients may be needed to guarantee the growth in a energy-wood stand of downy birch over its entire rotation. / Tiivistelmä Turvetuotannon päätyttyä jäljelle jäävä suopohja on aluksi täysin paljas ja vailla maaperän siemenpankkia. Kasvipeitteen luontainen uudistuminen voi viedä jopa vuosikymmeniä. Ympäristönhoidollisesti onkin tärkeää, että suopohjat otetaan uuteen käyttöön mahdollisimman nopeasti tuotannon päätyttyä. Metsitys on tällä hetkellä suosituin suopohjien jälkikäyttömuoto Suomessa. Suopohjan turpeessa on tyypillisesti runsaasti typpeä, mutta niukasti muita kasvuun tarvittavia ravinteita. Puutuhka on osoittautunut pitkäaikaisissa metsäojitettujen turvemaiden tutkimuksissa kilpailukykyiseksi vaihtoehdoksi kaupallisille lannoitteille. Energiantuotannon sivutuotteena syntyvä puu- ja turvetuhka voisi soveltua hyvin myös suopohjien lannoitteeksi. Tuhkan käytöstä lannoitteena turvetuotannosta vapautuneilla suopohjilla ei kuitenkaan ole riittävästi tutkimustietoa. Tässä työssä tutkittiin puu- ja turvetuhkan vaikutuksia turvetuotannosta vapautuneen suopohjan kasvittumiseen ja puun taimien alkukehitykseen viiden ensimmäisen kasvukauden ajan. Lisäksi tutkittiin kasvillisuuden ravinne- ja raskasmetallipitoisuuksien muutoksia sekä turpeen ravinteisuutta lannoituksen jälkeen. Kaikki lannoitteet nopeuttivat merkittävästi kasvillisuuden muodostumista paljaalle suopohjalle, kun taas lannoittamaton alue pysyi kasvittomana. Tuhkalannoitetuille alueille syntyi nopeasti laajoja palopaikoilla viihtyvien pioneerisammalten kasvustoja, jotka peittivät ja samalla sitoivat paljaan ja irtonaisen turvemaan pinnan. Tuhkalannoitus edisti myös koivun taimien alkukehitystä tehokkaammin kuin kaupallinen Metsän PK-lannoite. Sammalista ja ruohovartisista kasveista muodostuva aluskasvillisuus ylitti puuntaimet selvästi biomassan määrässä ja toimi metsityksen alkuvaiheessa puuntaimia merkittävämpänä hiilensitojana. Lisäksi kasvien maanalainen biomassa oli maanpäällistä biomassaa suurempi. Sekä puu- että turvetuhka takasivat riittävän määrän ravinteita energiapuumetsikön alkukehitykselle. Aluskasvillisuus osoittautui tärkeäksi tuhkasta liukenevien ravinteiden ja raskasmetallien sitojaksi metsityksen alkuvaiheessa. Vaikka sammalten kadmiumpitoisuudet nousivat tuhkalannoituksen seurauksena, ne olivat kuitenkin alhaisia Suomessa aiemmin mitattuihin sammalten yleisiin pitoisuuksiin suhteutettuna. Tuhkalannoitus ei lisännyt haitallisten raskasmetallien pitoisuuksia koivun taimien ja ruohovartisten kasvien lehdissä ja varsissa. Tutkimuksen tulokset tukevat puu- ja turvetuhkan käyttöä energiapuumetsiköiden alkuvaiheen lannoitteena turvetuotannosta vapautuneilla suopohjilla.

Abstract Broadleaved forests are highly valuable biotopes with important recreational value and contain rich occurrences of species of conservation concern. To monitor the development of nature values in a forest ecosystem during an interval of approximately ten years, follow-up inventories were carried out, following the first inventories which took place ten years ago in two nature reserves (Karlsvik and Bohult) dominated by broadleaved trees in the county of Halland, Sweden. Indicator species of lichen and moss were searched for and compared to the first inventories. The results show that both reserves contain more indicator species today than approximately ten years ago, though a change in the species composition was observed. In Bohult fewer indicator lichens were observed, although more observations were made of indicator mosses - making the total number of indicator species higher than in the previous inventory. Potential explanations to the differing results of the two reserves were discussed and assessed to be for varied reasons. The observed increased occurrences of indicator species may be due to increased continuity leading to bigger and older trees which make way for more epiphytes. The observed decreased occurrences of indicator species may be due to human activity such as newly carried out clearcutting in close proximity to the reserve (which could lead to edge effects or other environmental stresses), nitrogen deposition or exploitation. An observed threat for both reserves is the increasing growth of norway spruce (Picea abies) which may outcompete broadleaved species and the potential indicator species they may inhabit. / Sammanfattning Ädellövskogar är mycket värdefulla naturtyper med höga rekreationsvärden och med rika förekomster av naturvårdsarter. För att utvärdera förändringen av skogliga naturvärden inom en tidsperiod av ca tio år utfördes uppföljningsinventeringar av två tidigare inventerade naturreservat som domineras av ädellövskog i Hallands län i Sverige. Signalarter av lavar och mossor eftersöktes och jämfördes med tidigare funna signalarter. Båda reservatens ursprungliga inventeringar utfördes för ca tio år sedan och resultaten visar att de båda reservaten nu har fler signalarter än tidigare, samtidigt som en förändring observerades i artsammansättningen då samtliga signalarter ej återfanns. I Bohult observerades färre signalartslavar, men fler signalartsmossor - vilket resulterade i ett större antal signalarter totalt för området. Potentiella förklaringar till de skilda förändringarna diskuterades och bedömdes bero på varierande orsaker. Det större antalet observerade signalarter skulle kunna förklaras av ökad tid för kontinuitet med fler grova och äldre träd som utgör lämpliga substrat för kolonisering av de eftersökta signalarterna. Det färre antalet observerade signalartslavar i Bohult skulle kunna bero på mänsklig påverkan i form av nyligen utförda kalavverkningar i angränsning till reservatet, vilket kan bidra till kanteffekter eller andra påfrestningar på miljön. Kvävenedfall, dikning av vattendrag eller annan exploatering föreslås också som möjlig orsak. Ett observerat hot för båda reservaten var igenväxningen av gran, vilken skulle kunna konkurrera med ädellövträden och de signalarter de kan husera.

In this dissertation I propose an ethical framework for "meeting mosses." At first glance, mosses are a tiny type of plants that have been uncritically understood as "primitive plants," to the extent that they are defined by negation as "non-vascular plants." Hence, mosses have been considered as "primitive" relatives of "true" vascular plants. This distortion is linked to the fact that mosses have been overlooked and represented as a radical otherness in Western civilization. To critically examine this distortion of, and injustice toward mosses, I use the methodology of field environmental philosophy within the conceptual framework of biocultural ethics developed by Ricardo Rozzi. I complement these concepts with foundational philosophical work by continental philosophers Martin Buber and Immanuel Levinas, and ethnobotanist and indigenous writer Robin Wall Kimmerer, with emphasis on their discourses of meeting, "face-to-face," otherness, heterogeneity, and alterity. Collectively thinking with these philosophers, I address the possibility of genuinely "meeting mosses," valuing them as such and not merely as a primitive "relative" or "ancestor" of vascular plants. Drawing on several botanists' accounts of plant language and plant wisdom has sharpened my reading of human-moss interactions and enriched my engagement with the heterogeneity and alterity of the Western philosophical tradition. In his book Gardens: An Essay on the Human Condition, Humanist scholar Robert Pogue Harrison argues that care (for plants and life) is the human vocation. Harrison's discussion of the diversity of "gardens" helped me to clarify multi-dimensional human-moss interactions. In terms of content and structure, I organize my analysis based on two central dimensions of human-plant interactions stated in Rozzi's biocultural ethics: biophysical and cultural, particularly, symbolic-linguistic dimensions. I explore the biophysical dimension of biocultural conservation focusing on mosses in a region where they represent the most diverse and abundant type of plants, southwestern South America. In this region, I conducted fieldwork at three reserves in Chile, Senda Darwin Biological Reserve on Chiloe Island, Magallanes National Reserve, and Omora Ethnobotanical Park in the Cape Horn Biosphere Reserve, south of Tierra del Fuego. I investigate the linguistic-cultural dimension, through the scientific binomial nomenclature as well as through the traditional naming by indigenous cultures, particularly in China. Additionally, I examine the arts as an important cultural expression of interacting with mosses that inspires biocultural conservation. I examine the role that the arts play in the education and conservation programs at the Omora Ethnobotanical Park in Chile and Shenzhen Fairy Lake Botanical Garden in China, as a way to invite students and others to have direct encounters with mosses which lead to hands-on (tactile and place-based) moss conservation. I begin this study with a deliberation of the multiple injustices embedded in contemporary social-ecological-cultural dimensions of global change, and I suggest pathways towards caring for plants and the diversity of life. Caring for mosses is not a one-way human-plant-directed process. By nourishing our physical and cultural lives, we can metaphorically say that mosses "take care" of humans. Once we integrate both "caring for mosses" and being sensitive to the "mosses caring for us," then biocultural conservation moves towards a more reciprocal conviviality. In addition to collectively thinking with other humans, metaphorically I aim to think and feel with the mosses, and therefore I am transformed by them. This is the ultimate meaning of "meeting mosses."

Folgende Themenkomplexe wurden behandelt: Biogeographie, Pflanzendiversität, Verbreitungsmuster von Lebensformen und Arten in Mikrohabitaten sowie entlang ökologischer Gradienten, Epiphyt-Porophyt-Beziehungen, Vergesellschaftung, Sekundärsukzession und die Auswahl von Indikatorarten. Zum ersten Mal wird bei einer derartigen Untersuchung die sekundäre Sukzession von Kryptogamengesellschaften in tropischen Bergregenwäldern voll berücksichtigt. Die Untersuchung wurde im Einzugsgebiet des Río Savegre auf der pazifikseitigen Abdachung der westlichen Cordillera de Talamanca (Costa Rica) durchgeführt.Kapitel 1 gibt eine generelle Einführung in Tropische Bergregenwälder und die Bedeutung von Moosen und Makroflechten als wichtige Komponenten dieser Ökosysteme. Der Leser wird in das Untersuchungsgebiet, sein Klima, seine Geologie und seine Vegetation eingeführt.Im Kapitel 2 werden die pflanzengeographischen Muster der Moose montaner Eichenwälder der Cordillera de Talamanca dargestellt und diskutiert.Kapitel 3 diskutiert Diversität, Mikrohabitatdifferenzierung und Lebensformenspektren der Moose in einem hochmontanen Eichenwald Costa Ricas. Es wurde versucht, die Moosflora aller Mikrohabitate eines Eichenwaldes, inklusive der Strauch- und Bodenschicht zu erfassen. Kapitel 4 und 5 beinhalten die Beschreibung epiphytischer Kryptogamengesellschaften (Moose und Makroflechten) in Primär- und Sekundärwäldern. Mit Hilfe einer aus dem Alpinismus abgeleiteten Klettertechnik wurden Bäume von der Stammbasis bis in die Zweige der äußeren Krone beprobt. Die Vegetationsaufnahmen repräsentieren die Variation der epiphytischen Vegetation. Prozentuale Deckungsgrade der rindenbewohnenden Moose und Makroflechten wurden geschätzt und mit Hilfe einer Detrended Correspondence Analysis (DCA)' und nicht-metrischer Multi-response Permutation Procedure (MRPP)' verglichen. Rindenproben der untersuchten Bäume wurden mit deionisiertem Wasser extrahiert und der pH-Wert bestimmt.Kapitel 4 behandelt die epiphytischen Kryptogamengemeinschaften auf den dominierenden Baumarten (Quercus copeyensis und Q. costaricensis) primärer, hochmontaner Eichenwälder Costa Ricas. Kapitel 5 vergleicht Artenreichtum, Vergesellschaftung und Ökologie der epiphytischen Kryptogamen in primären und sekundären hochmontanen Eichenwäldern Costa Ricas. Quercus copeyensis-Bäume der oberen Baumschicht von Primär- und Sekundärwäldern wurden beprobt mit dem Ziel einen Einblick in Regenerationspotential, -muster und -prozesse der Epiphytensukzession nach anthropogener Störung zu erhalten.