Category: Review article
article id 1673,
category Review article,
4278 views
Eshetu Yirdaw,
Mulualem Tigabu,
Adrian Monge.
(2017).
Rehabilitation of degraded dryland ecosystems – review.
Silva Fennica
vol. 51
no. 1B
article id 1673.
https://doi.org/10.14214/sf.1673
Highlights:
The prospect of restoring degraded drylands is technically promising; The forest landscape restoration concept can be used as the overarching rehabilitation framework; Development of process-based models that forecast rehabilitation outcomes is needed; Rehabilitation methodologies developed for moist areas are not necessarily suitable for drylands; More data is needed on cost-benefit analysis of rehabilitation interventions.
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Land degradation is widespread and a serious threat affecting the livelihoods of 1.5 billion people worldwide of which one sixth or 250 million people reside in drylands. Globally, it is estimated that 10–20% of drylands are already degraded and about 12 million ha are degraded each year. Driven by unsustainable land use practices, adverse climatic conditions and population increase, land degradation has led to decline in provision of ecosystem services, food insecurity, social and political instability and reduction in the ecosystem’s resilience to natural climate variability. Several global initiatives have been launched to combat land degradation, including rehabilitation of degraded drylands. This review aimed at collating the current state-of-knowledge about rehabilitation of degraded drylands. It was found that the prospect of restoring degraded drylands is technically promising using a suite of passive (e.g. area exclosure, assisted natural regeneration, rotational grazing) and active (e.g. mixed-species planting, framework species, maximum diversity, and use of nurse tree) rehabilitation measures. Advances in soil reclamation using biological, chemical and physical measures have been made. Despite technical advances, the scale of rehabilitation intervention is small and lacks holistic approach. Development of process-based models that forecast outcomes of the various rehabilitation activities will be useful tools for researchers and practitioners. The concept of forest landscape restoration approach, which operates at landscape-level, could also be adopted as the overarching framework for rehabilitation of degraded dryland ecosystems. The review identified a data gap in cost-benefit analysis of rehabilitation interventions. However, the cost of rehabilitation and sustainable management of drylands is opined to be lower than the losses that accrue from inaction, depending on the degree of degradation. Thus, local communities’ participation, incorporation of traditional ecological knowledge, clear division of tasks and benefits, strengthening local institutions are crucial not only for cost-sharing, but also for the long-term success of rehabilitation activities.
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Yirdaw,
Viikki Tropical Resources Institute (VITRI), Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland
E-mail:
eshetu.yirdaw@helsinki.fi
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Tigabu,
Sveriges Lantbruks Universitet (SLU), Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53, Alnarp, Sweden
E-mail:
Mulualem.Tigabu@slu.se
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Monge,
Viikki Tropical Resources Institute (VITRI), Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland
E-mail:
adrian.mongemonge@helsinki.fi
article id 1660,
category Review article,
2893 views
Highlights:
Annual growth is 287 million m3 in the forests of the Nordic and Baltic countries; Growth can be increased by new tree species, tree breeding, high-productive management systems, fertilization and afforestation of abandoned agricultural land; We predict a forest growth increment of 50–100% is possible at the stand scale; 65% of annual growth is harvested today.
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The Nordic and Baltic countries are in the frontline of replacing fossil fuel with renewables. An important question is how forest management of the productive parts of this region can support a sustainable development of our societies in reaching low or carbon neutral conditions by 2050. This may involve a 70% increased consumption of biomass and waste to meet the goals. The present review concludes that a 50–100% increase of forest growth at the stand scale, relative to today’s common level of forest productivity, is a realistic estimate within a stand rotation (~70 years). Change of tree species, including the use of non-native species, tree breeding, introduction of high-productive systems with the opportunity to use nurse crops, fertilization and afforestation are powerful elements in an implementation and utilization of the potential. The productive forests of the Nordic and Baltic countries cover in total 63 million hectares, which corresponds to an average 51% land cover. The annual growth is 287 million m3 and the annual average harvest is 189 million m3 (65% of the growth). A short-term increase of wood-based bioenergy by utilizing more of the growth is estimated to be between 236 and 416 TWh depending on legislative and operational restrictions. Balanced priorities of forest functions and management aims such as nature conservation, biodiversity, recreation, game management, ground water protection etc. all need consideration. We believe that these aims may be combined at the landscape level in ways that do not conflict with the goals of reaching higher forest productivity and biomass production.
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Rytter,
The Forestry Research Institute of Sweden (Skogforsk), Ekebo 2250, SE-26890 Svalöv, Sweden
E-mail:
lars.rytter@skogforsk.se
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Ingerslev,
Copenhagen University, Department of Geosciences and Natural Resource Management, Rolighedsvej 23, DK-1958, Frederiksberg C, Denmark
E-mail:
moi@ign.ku.dk
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Kilpeläinen,
Finnish Environment Institute, Joensuu Office, P.O. Box 111, FI-80101 Joensuu, Finland; University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland
E-mail:
antti.kilpelainen@ymparisto.fi
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Torssonen,
University of Eastern Finland, Faculty of Science and Forestry, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland
E-mail:
Piritta.Torssonen@uef.fi
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Lazdina,
Latvian State Forest Research Institute “Silava”, 111 Riga str, Salaspils, LV 2169 Latvia
E-mail:
Dagnija.Lazdina@silava.lv
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Löf,
Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Box 49 SE-230 53 Alnarp, Sweden
E-mail:
magnus.lof@slu.se
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Madsen,
Copenhagen University, Department of Geosciences and Natural Resource Management, Rolighedsvej 23, DK-1958, Frederiksberg C, Denmark
E-mail:
pam@ign.ku.dk
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Muiste,
Estonian University of Life Sciences, Institute of Forestry and Rural Engineering, Dept. Forest Industry, Kreutzwaldi 5, Tartu 51014, Estonia
E-mail:
Peeter.Muiste@emu.ee
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Stener,
The Forestry Research Institute of Sweden (Skogforsk), Ekebo 2250, SE-26890 Svalöv, Sweden
E-mail:
Lars-Goran.Stener@skogforsk.se
Category: Research article
article id 1564,
category Research article,
2731 views
Stanislav Vacek,
Zdeněk Vacek,
Lukáš Bílek,
Jaroslav Simon,
Jiří Remeš,
Iva Hůnová,
Jan Král,
Tereza Putalová,
Miroslav Mikeska.
(2016).
Structure, regeneration and growth of Scots pine (Pinus sylvestris L.) stands with respect to changing climate and environmental pollution.
Silva Fennica
vol. 50
no. 4
article id 1564.
https://doi.org/10.14214/sf.1564
Highlights:
Pine forest stands showed positive development of stand structural characteristics related to their diversity, number of regeneration individuals and growth characteristics; Tree-ring width was positively correlated with precipitation, while it was negatively correlated with temperature in growing seasons; Mean NOx concentrations showed positive effect on radial growth of pine; Serious defoliation was caused by SO2 concentrations and N deposition in combination with extreme climate events.
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Changes in the structure and development of managed Scots pine (Pinus sylvestris L.) stands with respect to changing environmental conditions were set for the period 1979–2015. The study was conducted in conditions of natural pinewoods and pine-oak sites on five permanent research plots (0.25 ha) in Eastern Bohemia, Czech Republic (CR). Studied forest stands showed positive development of stand structural characteristics related to their diversity, number of regeneration individuals and growth characteristics. The standing volume of regularly distributed tree layer in 2015 was in the range of 320–434 m3 ha–1, which indicates an increase by 5.9–20.0% over 10 years. Correlation between pine radial increment and the amount of precipitation was generally the strongest one. Positive statistically significant correlation between diameter increment and temperature was demonstrated only for the average March temperature of the current year. Within the CR, study site can be characterised as a medium polluted area both for sulphur and nitrogen, despite this SO2 concentrations and N deposition in combination with extreme climate events caused severe defoliation in pine stands. Conversely, radial growth was positively significantly correlated with mean NOx concentrations. Drought mainly in combination with even medium environmental pollution can further worsen the health status of pine stands in lowland areas of Central Europe. Thus, formulation of silvicultural techniques able to mitigate the impact of these stress factors is needed.
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Vacek,
Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic
E-mail:
vacekstanislav@fld.czu.cz
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Vacek,
Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic
E-mail:
vacekz@fld.czu.cz
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Bílek,
Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic
E-mail:
bilek@fld.czu.cz
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Simon,
Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 3, 613 00 Brno, Czech Republic
E-mail:
jaroslav.simon@mendelu.cz
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Remeš,
Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic
E-mail:
remesj@email.cz
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Hůnová,
Czech Hydrometeorological Institute, Na Šabatce 17 143 06 Prague, Czech Republic
E-mail:
hunova@chmi.cz
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Král,
Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic
E-mail:
kraljan@fld.czu.cz
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Putalová,
Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague, Czech Republic
E-mail:
putalova@fld.czu.cz
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Mikeska,
University of Hradec Králové, Faculty of Science, Rokitanského 62, 500 03 Hradec Králové, Czech Republic
E-mail:
Mikeska.Miroslav@uhul.cz
article id 1462,
category Research article,
2455 views
Highlights:
Mire drainage shifted floristic composition and ant assemblages towards forest communities; Raising the water-table level by ditch filling and the thinning of trees affected mire communities positively already 1–3 years after the start of restoration; The extent of tree cover, the coverage of Sphagnum mosses and the water-table level were major determinants of ant assemblage structure.
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Habitat loss and degradation are the main threats to biodiversity worldwide. For example, nearly 80% of peatlands in southern Finland have been drained. There is thus a need to safeguard the remaining pristine mires and to restore degraded ones. Ants play a pivotal role in many ecosystems and like many keystone plant species, shape ecosystem conditions for other biota. The effects of mire restoration and subsequent vegetation succession on ants, however, are poorly understood. We inventoried tree stands, vegetation, water-table level, and ants (with pitfall traps) in nine mires in southern Finland to explore differences in habitats, vegetation and ant assemblages among pristine, drained (30–40 years ago) and recently restored (1–3 years ago) pine mires. We expected that restoring the water-table level by ditch filling and reconstructing sparse tree stands by cuttings will recover mire vegetation and ants. We found predictable responses in habitat structure, floristic composition and ant assemblage structure both to drainage and restoration. However, for mire-specialist ants the results were variable and longer-term monitoring is needed to confirm the success of restoration since these social insects establish perennial colonies with long colony cycles. We conclude that restoring the water-table level and tree stand structure seem to recover the characteristic vegetation and ant assemblages in the short term. This recovery was likely enhanced because drained mires still had both acrotelm and catotelm, and connectedness was still reasonable for mire organisms to recolonize the restored mires either from local refugia or from populations of nearby mires.
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Punttila,
Finnish Environment Institute, P.O. Box 140, FI-00251 Helsinki, Finland
E-mail:
pekka.punttila@ymparisto.fi
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Autio,
Centre for Economic Development, Transport and the Environment in South Ostrobothnia, P.O. Box 252, FI-65101 Vaasa, Finland
E-mail:
olli.autio@ely-keskus.fi
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Kotiaho,
University of Jyväskylä, Department of Biology & Environmental Sciences, P.O. Box 35, FI-40014 Jyväskylä, Finland
E-mail:
janne.kotiaho@jyu.fi
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Kotze,
University of Helsinki, Department of Environmental Sciences, P.O. Box 65, FI-00014, University of Helsinki, Finland
E-mail:
johan.kotze@helsinki.fi
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Loukola,
University of Oulu, Department of Biology, P.O. Box 3000, FI-90014 Oulu, Finland
E-mail:
olli.loukola@gmail.com
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Noreika,
University of Helsinki, Department of Environmental Sciences, P.O. Box 65, FI-00014, University of Helsinki, Finland; University of Helsinki, Department of Biosciences, P.O. Box 65, FI-00014 University of Helsinki, Finland
E-mail:
norbertas.noreika@gmail.com
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Vuori,
University of Jyväskylä, Department of Biology & Environmental Sciences, P.O. Box 35, FI-40014 Jyväskylä, Finland
E-mail:
anna@kureniemi.fi
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Vepsäläinen,
University of Helsinki, Department of Biosciences, P.O. Box 65, FI-00014 University of Helsinki, Finland
E-mail:
kari.vepsalainen@helsinki.fi
Category: Review article
article id 1008,
category Review article,
2415 views
Janusz Szmyt.
(2014).
Spatial statistics in ecological analysis: from indices to functions.
Silva Fennica
vol. 48
no. 1
article id 1008.
https://doi.org/10.14214/sf.1008
Highlights:
Spatial statistics provides a quantitative description of natural variables distributed in space and time; The objectives of spatial analysis are to detect spatial patterns and to confirm if a pattern found is significant; Spatially explicit indices and functions may be applied depending on the information collected from the field; Development of the specific software supports spatial analyses.
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This paper presents a review of the most common methods in ecological studies aimed at spatial analysis of population structures (horizontal and vertical), based on point process statistics. Methods based on simple spatially explicit indices as well as more sophisticated methods relying on functions are described in a comprehensible manner. Simple indices revealing the information on spatial structure at the scale of the nearest neighbor can be easily implemented in practical forestry. On the other hand, spatial functions, based on much more detailed data, describe the spatial structure in terms of the spatial relationships between the natural processes and population structures and because of this complexity they are rarely used in forest practice. Including both methods in a single paper is also valuable from the potential reader’s point of view saving their time for searching and choosing the appropriate method to make their spatial analysis. This paper can also serve as an initial guide for young researchers or those who are going to start their studies on spatial aspects of bio-systems. Avoiding the statistical and mathematical details makes this paper understandable for readers who are not statisticians or mathematicians. Readers will find many references related to each method described here, allowing them to find solutions to different problems observed in practice. This paper ends with a list of the most common specific software packages available to support spatial analysis.
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Szmyt,
Department of Silviculture, Faculty of Forestry, Poznań University of Life Sciences, ul. Wojska Polskiego 69, 60-625 Poznań, Poland
E-mail:
jszmyt@up.poznan.pl