The status and role of genetic diversity of trees for the conservation and management of riparian ecosystems: a European experts' perspective

Riparian vegetation supports high biodiversity providing many services and is, therefore, an important landscape element. Riparian ecosystems are subject to numerous pressures leading to population decline and genetic erosion of riparian plants. This may have cascading effects at various ecosystem levels, including decreasing ecosystem services, so identifying the current status of genetic diversity of riparian tree species is vital to improve the effectiveness of restoration efforts. We aimed to elicit expert views on the status and importance of genetic diversity of tree species, and conservation needs across European riparian ecosystems. Sharing of such information among researchers, managers and policymakers has the potential to enhance ecological restoration and management of riparian ecosystems. We identified experts in riparian genetic resources conservation and management across Europe. These included stakeholders with different perspectives, ranging from researchers to practitioners. We designed a set of questionnaires where our identified experts were asked to answer questions related to the status and conservation of genetic diversity of riparian tree species in their respective countries. Specifically, we asked about societal awareness, legislative tools, good practices and conservation or restoration projects accounting for intraspecific genetic diversity and differentiation of tree species in riparian ecosystems. Questionnaire responses were analysed and discussed in light of the scientific literature to define needs and priorities related to the management and conservation of genetic diversity of riparian tree species. The experts recognized that a combination of in situ and ex situ measures and/or integrative conservation of riparian ecosystems is the most appropriate option for conserving the genetic diversity of riparian tree species. Simultaneous application of conservation measures at the level of priority species, identified by experts, and protection of riparian areas are required. Synthesis and applications. This study revealed the importance of recognizing the ecological processes that shape the genetic diversity of riparian tree species in hydrographic networks (dendritic spatial configuration, specific patterns of gene flow among riparian populations, fragmentation of river by dams) but also the need to overcome socio-economic barriers, such as lack of policy priority, deficiency in funding and weak legislation framewor

Bringing the margin to the focus: 10 challenges for riparian vegetation science and management

Riparian zones are the paragon of transitional ecosystems, providing critical habitat and ecosystem services that are especially threatened by global change. Following consultation with experts, 10 key challenges were identified to be addressed for riparian vegetation science and management improvement: (1) Create a distinct scientific community by establishing stronger bridges between disciplines; (2) Make riparian vegetation more visible and appreciated in society and policies; (3) Improve knowledge regarding biodiversity—ecosystem functioning links; (4) Manage spatial scale and context-based issues; (5) Improve knowledge on social dimensions of riparian vegetation; (6) Anticipate responses to emergent issues and future trajectories; (7) Enhance tools to quantify and prioritize ecosystem services; (8) Improve numerical modeling and simulation tools; (9) Calibrate methods and increase data availability for better indicators and monitoring practices and transferability; and (10) Undertake scientific validation of best management practices. These challenges are discussed and critiqued here, to guide future research into riparian vegetation

Riparian Zones—From Policy Neglected to Policy Integrated

1. Riparian zones are vital areas of interaction between land and rivers and are often degraded by several pressures such as urbanisation, intensive agriculture and river engineering works. 2. This policy brief provides five key policy messages and recommendations to be considered by policy-makers, scientists, managers, and stakeholders to enhance riparian zone management. 3. Adopting an integrated socioeconomic and environmentally dynamic view will ensure the sustainable management of riparian zones. 4. In light of climate change, it is critically important to conserve and/or restore the ecological integrity of riparian zones. 5. European Union Directives and national-scale legislation and regulations need updating to ensure coordinated implementation of riparian zone-related policies. 6. Stakeholder knowledge exchange, policy co-creation and adaptive management are key to enhancing riparian zone functions

Stakeholder analysis for coppice forestry in Bulgaria

<span>The study analyzes the state of coppice forestry in Bulgaria during last 18 years. Stakeholders and their interests and preferences in coppice forests are explored and assessed. Forests restitution process in Bulgaria started in 1997 and has not been finished yet. Nevertheless, significant further changes of the current ownership distribution are not expected. By the end of 2007, the state was the biggest coppice forest owner/stakeholder in Bulgaria with 71.3% of all coppice forests being state property. The other two important stakeholders are the municipalities (14.0%) and private owners (12.0%). Currently, forest owners' number in Bulgaria exceeds 1 million, the average holding area being smaller than 1 ha. Only 150 individual plots are larger than 50 ha. The majority of private owners aim at taking maximum and immediate profit from their recently restituted forest properties. In most cases that reflects in clearcuts. Coppice forests management has been one of the problematic issues of Bulgarian forestry for decades. Despite of forest authorities significant efforts, the area of coppice forests in Bulgaria (1.78 million ha in 2007) remained unchanged for a period of 50 years. The official forest policy is still aimed at conversion of coppice forests into seed ones through different silvicultural methods. That policy is applied to almost all coppice forests regardless of their ownership.</span

Old-growth forests in Bulgaria: distribution, characteristics and conservation issues

Natural diversity of relief, climate variability, geographical as well as historical reasons contribute to the presence of old-growth forest patches in various forest types in Bulgaria. For reasons of biodiversity protection, scientific studies and forest certification several projects aimed at locating and collecting data for old-growth forests in Bulgaria. Our aim is to summarize the available findings and contribute for a general map of these forests. The sources of data combine inventory data, including fieldwork collection of forest structure data by members of our team, and verification of satellite and aerial images. Most widely distributed old-growth forests in the country are Fagus sylvatica in the Balkan Range Mountains. Isolated patches of old oak forests were preserved in the lower mountains and lowlands. Coniferous forests were preserved on hardly accessible steep slopes or deep valleys in the high mountains in southern Bulgaria. Of them most impressive are Pinus peuce and Pinus heldreichii forests in the Pirin Mountains, Picea abies forests in Rila and Rhodopes Mts., Pinus nigra in the Rhodopes and beech-fir-spruce forests in isolated locations. There is also one Juniperus excelsa forest, which although affected in the past by selective logging and pasturing, still preserves the largest species locality on the Balkan Peninsula with trees often exceeding 150-200 years. Old-growth beech forests are characterized by numerous small-sized gaps. Dead wood amount largely varies depending of site condition and past disturbances but rarely exceeds 100 m3/ha. DBH distributions resemble a rotated sigmoidal curve (Zlatanov et al. 2013). Old-growth Picea-dominated forests are characterized by younger and older patches resulting from windthrows and rarely fires of various sizes. Dead wood often exceeds 70-100 m3/ha. DBH distribution is resembles J-reversed. Typical for old-growth pine forests in the Pirin Mts. is high number of live old and dead trees with DBH often exceeding 100 cm and age &gt; 500. Most important disturbances were fires, avalanches and rarely windthrows (Panayotov et al. 2017). Numerous fire traces in old Pinus nigra forests show that they were shaped by periodic fires. However, present day fire exclusion and past management guide dynamics towards increase of deciduous species in the understory. The total amount of deadwood rarely exceeds 30-40 m3/ha. The biggest threat to old-growth forests in Bulgaria is logging, including the potentially desired sanitary fellings in National Parks. In few locations conflicts arise also from desires to expand tourist infrastructure in old-growth forests. References: 1. Panayotov et al., 2017. Abiotic disturbances in Bulgarian mountain coniferous forests - an overview. Forest Ecology and Management, 388:13-28 2. Zlatanov et al., 2013. Index for identification and evaluation of old-growth forests in Bulgaria. Forest science, 17-28peerReviewe

Does management improve the state of chestnut (Castanea sativa L.) on Belasitsa Mountain, southwest Bulgaria?

Chestnut forests in the Belasitsa Mountain region of southwest Bulgaria were traditionally intensively managed as orchard-like stands for nut production. More recently, management intensity has been sharply reduced as a result of rural abandonment, which combined with the effects of chestnut blight has led to marked structural changes in these forests. The focus of this paper is on the seed-based regeneration potential and seedling survival of chestnut in mixed stands managed over the past 15 years. Results suggest that management of stands under a high-forest system is appropriate, and regeneration from seed has advantages over coppicing if competing species can be controlled. An investigation into “sanitation cutting” performed since the 1990s shows that this had not a successful response to blight infestations

Krivulje indeksa staništa za pitomi kesten (Castanea sativa Mill.) na planini Belasici

Richards, Lundqvist-Korf and Hossfeld growth functions were fitted to age-height data of European chestnut (Castanea sativa Mill.) dominant trees on the northern slopes of Belasitsa mountain, Southwest Bulgaria. The model prediction performance was evaluated using quantitative as well as qualitative examinations. Goodness of fit of each model was estimated by the coefficient of determination, F-test for significance of the regression and t-tests for significance of the coefficients of the model. Models were further compared by the evaluation of the standard error of the model and Akaike’s Information Criteria. Site index curves were constructed following the &quot;guide curve method&quot; procedure. In accordance with the evaluation tests, the Richards function was chosen as most adequate to express the age-dominant height relationship. Accordingly, it was further employed as a guide function to derive site index curves for studied chestnut population. It was recommended that the growth model and the site index curves elaborated in the current study are used within the data range 10&#8722;110 years.U ovome su radu jednadžbe rasta koje su razvili Richards (jednadžba 1), Lundqvist-Korf (jednadžba 2) i Hossfeld (jednadžba 3) upotrijebljene za modeliranje dominantne visine populacije stabala pitomoga kestena (Castanea sativa Mill.) sa sjevernih ekspozicija planine Belasitsa u jugozapadnoj Bugarskoj. Mogućnost predikcije dominantnih visina pomoću izrađenih modela procijenjena je koristeći kvantitativne i kvalitativne kriterije. Uklapanje linije izjednačenja svakoga modela procijenjena je pomoću koeficijenta determinacije R2, F-testa značajnosti regresije i t-testa značajnosti parametara modela. Nadalje, modeli su međusobno uspoređeni kroz evaluaciju standardne pogreške modela (Sy) i AIC kriterija (Akaike’s Information Criteria). Linije svih upotrijebljenih funkcija rasta zadovoljavajuće naliježu na podatke ovisnosti visine o starosti. Uklapanje linija izjednačenja za sve je modele statistički značajno na razini &#945; &lt; 0.01, pri čemu se objašnjava najmanje 60 % cjelokupne varijabilnosti dominantne visine stabala pitomoga kestena. Funkcija Richardsa pokazala je marginalno bolje rezultate od ostala dva modela s koeficijentom determinacije od R2 = 0.62 (tablica 1). Ovaj je model također imao i najmanje vrijednosti standardne pogreške (Sy) i AIC kriterija. Nadalje, funkcije Lundqvist-Korfa i Hossfelda daju krivulju koja odstupa od asimptotskoga trenda u većoj mjeri nego krivulja Richardsa (slika 1), pri čemu se ova zadnja smatra bližom biološkim zakonitostima rasta. U skladu s provedenim analizama, funkcija Richardsa odabrana je kao najpovoljniji model ovisnosti dominantne visine o starosti, te je dalje upotrijebljena za izradu krivulja indeksa staništa za istraživanu populaciju pitomoga kestena (slika 3). Za određenu starost i dominantnu visinu, indeks staništa može se izraditi i pomoću jednadžbe 10. Dobiveni model visinskoga rasta kao i krivulje indeksa staništa mogu se koristiti u starosnom rasponu od 10 do 110 godina

A methodological approach for monitoring of riparian forests in protected areas on Danube islands

In the last decades, invasive plant species have rapidly settled on the islands in the Danube River. This process is closely related to anthropogenic activities, such as felling and cultivation of soil for affor-estation of Euro-American poplar trees throughout the Danube River basin. In this regard, it is im-portant to: (i) determine the speed and scope of invasive vegetation establishment and (ii) determine more precisely the ongoing successional dynamics. Monitoring in permanent plots is needed to track the changes and assist in decision-making processes for the management of protected areas on the islands in the Danube River. The aim of the study is to describe and justify an innovative approach to analyse the dynamic of the invasion species occurrence and development as related to site conditions and management across the islands in the Danube River. The following methodological approach was considered: (1) selection of islands with well-preserved and sufficient in area covered by natural forest vegetation; (2) differentiation of strata by forest type, age and canopy cover; (3) setting up permanent sample plots for long-term monitoring in natural riparian forests

The status and role of genetic diversity of trees for the conservation and management of riparian ecosystems

Riparian vegetation supports high biodiversity providing many services and is, therefore, an important landscape element. Riparian ecosystems are subject to numerous pressures leading to population decline and genetic erosion of riparian plants. This may have cascading effects at various ecosystem levels, including decreasing ecosystem services, so identifying the current status of genetic diversity of riparian tree species is vital to improve the effectiveness of restoration efforts. We aimed to elicit expert views on the status and importance of genetic diversity of tree species, and conservation needs across European riparian ecosystems. Sharing of such information among researchers, managers and policymakers has the potential to enhance ecological restoration and management of riparian ecosystems. We identified experts in riparian genetic resources conservation and management across Europe. These included stakeholders with different perspectives, ranging from researchers to practitioners. We designed a set of questionnaires where our identified experts were asked to answer questions related to the status and conservation of genetic diversity of riparian tree species in their respective countries. Specifically, we asked about societal awareness, legislative tools, good practices and conservation or restoration projects accounting for intraspecific genetic diversity and differentiation of tree species in riparian ecosystems. Questionnaire responses were analysed and discussed in light of the scientific literature to define needs and priorities related to the management and conservation of genetic diversity of riparian tree species. The experts recognized that a combination of in situ and ex situ measures and/or integrative conservation of riparian ecosystems is the most appropriate option for conserving the genetic diversity of riparian tree species. Simultaneous application of conservation measures at the level of priority species, identified by experts, and protection of riparian areas are required. Synthesis and applications. This study revealed the importance of recognizing the ecological processes that shape the genetic diversity of riparian tree species in hydrographic networks (dendritic spatial configuration, specific patterns of gene flow among riparian populations, fragmentation of river by dams) but also the need to overcome socio-economic barriers, such as lack of policy priority, deficiency in funding and weak legislation framework