Forest inventory-based assessments of the invasion risk of Pseudotsuga menziesii (Mirb.) Franco and Quercus rubra L. in Germany

AbstractIn Europe, some non-native tree species (NNT) are classified as invasive because they have spread into semi-natural habitats. Yet, available risk assessment protocols are often based on a few limited case studies with unknown representativeness and uncertain data quality. This is particularly problematic when negative impacts of NNT are confined to particular ecosystems or processes, whilst providing valuable ecosystem services elsewhere. Here, we filled this knowledge gap and assessed invasion risks of two controversially discussed NNT in Germany (Quercus rubra L., Pseudotsuga menziesii (Mirb.) Franco) for broad forest types using large scale inventory data. For this purpose, establishment success of natural regeneration was quantified in terms of cover and height classes. The current extent of spread into protected forest habitats was investigated in south-west Germany using regional data. Establishment was most successful at sites where the NNT are abundant in the canopy and where sufficient light is available in the understory. Natural regeneration of both NNT was observed in 0.3% of the total area of protected habitats. In forest habitats with sufficient light in the understory and competitively inferior tree species, there is a risk that Douglas fir and red oak cause changes in species composition in the absence of management interventions. The installation of buffer zones and regular removal of unwanted regeneration could minimize such risks for protected areas. Our study showed that forest inventories can provide valuable data for comparing the establishment risk of NNT amongst ecosystem types, regions or jurisdictions. This information can be improved by recording the abundance and developmental stage of widespread NNT, particularly in semi-natural ecosystems.

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Forest regeneration in northeastern Poland following a catastrophic blowdown

Canadian Journal of Forest Research ◽

10.1139/cjfr-2014-0507 ◽

2015 ◽

Vol 45 (9) ◽

pp. 1172-1182 ◽

Cited By ~ 9

Author(s):

Dorota Dobrowolska

Keyword(s):

Species Diversity ◽

Tree Species ◽

Natural Regeneration ◽

Large Scale ◽

Stand Structure ◽

Basal Area ◽

Tree Height ◽

Ground Cover ◽

Species Structure ◽

Tree Vitality

The aims of the investigation were to (i) quantify the changes in natural regeneration and stand structure, (ii) determine the role of deadwood in the process of regeneration following the disturbance, and (iii) determine the effect of disturbance severity on tree recruitment. The study was conducted in the Szast Protected Forest, which was established after a blowdown in 2002. The results showed that the trees were mainly wind-snapped. The basal area of the slightly disturbed stands increased over time. Herb cover increased, whereas moss cover decreased in 2011. The disturbance severity influenced the density of tree species regeneration, moss and herb ground cover, species diversity, average tree height, tree vitality, and damage caused by herbivores. The density of natural regeneration increased and new species became established after the disturbance. Scots pine (Pinus sylvestris L.) was the dominant tree species during the regeneration process except in the severely disturbed stand from which wood had been removed; in this case, birch was the dominant species. Wind disturbance increased species diversity and created a new forest with a particular species structure and trees that varied in age and height. The results of this study will be useful for foresters and policymakers to change the existing approaches to large-scale disturbances in the Polish forests.

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Comparison of the herb layer composition in stands of several tree species in the Louny region

Beskydy ◽

10.11118/beskyd201609010041 ◽

2016 ◽

Vol 9 (1-2) ◽

pp. 41-48

Author(s):

Jiří Viewegh ◽

Stanislav Miltner ◽

Karel Matějka ◽

Vilém Podrázský

Keyword(s):

Pinus Sylvestris ◽

Tree Species ◽

Natural Regeneration ◽

Quercus Rubra ◽

Quercus Petraea ◽

Ground Vegetation ◽

Red Oak ◽

Northern Red Oak ◽

Herb Layer ◽

Layer Composition

Influence of introduced northern red oak stands (Quercus rubra L.) on herb understory with comparison with herb understory of autochthonous Sessile oak (Quercus petraea agg. L) and Scots pine (Pinus sylvestris L.) was observed in Louny region area on 14 plots. The analysis of the ground vegetation was performed using classical phytosociological methods. Significant changes were not determined in the site character, when comparing particular tree species stands, the differences consisted especially in the natural regeneration of tree species. Northern red oak showed a tendency of more fast penetration in the neighboring stands.

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Invasivität der Douglasie in Südwestdeutschland: Waldinventurdaten erlauben eine Einschätzung

Schweizerische Zeitschrift fur Forstwesen ◽

10.3188/szf.2018.0086 ◽

2018 ◽

Vol 169 (2) ◽

pp. 86-92 ◽

Cited By ~ 2

Author(s):

Anja Bindewald ◽

Hans-Gerhard Michiels

Keyword(s):

Tree Species ◽

Natural Regeneration ◽

Native Species ◽

Douglas Fir ◽

Forest Types ◽

Inventory Data ◽

Buffer Zones ◽

Western Germany ◽

Negative Impacts ◽

Forest Habitats

Invasiveness of Douglas fir in south-western Germany: an assessment based on forest inventory data Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) is the most significant tree species of non-native origin in south-western Germany from a commercial point of view. Its importance is expected to increase in the effort to adapt forests to climate change because Douglas fir is considered to be more drought-resistant than, for instance, Norway spruce. Currently, the use of Douglas fir in silviculture and the assessment of its invasiveness are controversially discussed between representatives of nature conservation and forestry. Evidence-based evaluations of the current extent of the establishment and spread of the tree species provide an improved basis for the assessment of invasiveness, as they add objective facts to the discussion and increase the transparency of the process. In this article, we analyze the natural regeneration of Douglas fir in different forest types in the State of Baden-Wurttemberg (south-western Germany) with the help of three systematically collected inventory datasets. The existing natural regeneration serves as a measure for the successful establishment and spread of the species and provides information on its potential invasiveness, i.e. presumable negative impacts on native species and ecosystems. According to the inventory data, the natural regeneration of Douglas fir occurs at a low level (on only 0.3% of the forest surface in Baden-Wurttemberg). However, it naturally regenerates in special protected rare forest habitats, especially on open rocky sites and bolder fields and in sessile oak forest communities on dry sites with acidic soils and mixed broadleaved forests dominated by sycamore. Here, negative impacts might be possible. Thus the species can be considered potentially invasive in these specific conditions. Since Douglas fir natural regeneration was only reported on a proportion of 0.2% of the whole area of monitored protected forest habitats, it should still be possible to successfully eradicate this tree species from these habitats. Data on natural regeneration across a range of different forest types provide an improved basis for the assessment of invasiveness, and thus for identification of appropriate management approaches, such as designating buffer zones around valuable protected habitats.

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Soil solarization based on natural soil moisture: a practical approach for reducing the seed bank of invasive plants in wetlands

NeoBiota ◽

10.3897/neobiota.51.36838 ◽

2019 ◽

Vol 51 ◽

pp. 1-18

Author(s):

Oded Cohen ◽

Abraham Gamliel ◽

Jaacov Katan ◽

Iris Shubert ◽

Aviv Guy ◽

...

Keyword(s):

Soil Moisture ◽

Seed Bank ◽

Large Scale ◽

Invasive Plant ◽

Early Stage ◽

Natural Vegetation ◽

Soil Solarization ◽

Natural Soil ◽

Natural Ecosystems ◽

Natural Habitats

Soil solarization is a well-established method to disinfect soil for efficient weed control. However, the feasibility of applying this method in the restoration of invaded natural habitats is unclear. This is because soil moisture is necessary for the success of solarization, but pre-irrigation in natural ecosystems is often not applicable, or demands high labor investment, making it unsuitable for use in restoration. The present study was based on the idea that the relatively high soil moisture in wetlands might obviate the need for pre-irrigation, rendering this method much more applicable in natural habitats. We examined the efficacy of soil solarization using natural soil moisture to control the seed bank of the invasive plant, Acacia saligna, in a wetland, using large-scale experimental plots (0.38 ha each). An old, dense A. saligna grove was cut down and the roots were removed by a bulldozer. The plot was mulched with a transparent polyethylene sheet in early July and left on the soil for 14 weeks. Soil solarization significantly reduced the viability of seeds of A. saligna that had been experimentally buried. Additionally, viability of seeds in the natural seed bank was reduced, and seedling emergence was close to zero. Exposing seeds to soil temperature and soil moisture levels equivalent to those obtained during field soil solarization under controlled conditions significantly increased the release from dormancy of the seeds, suggesting that release from dormancy during the early stage of solarization is a critical stage leading to seed weakening or mortality in the soil. Soil solarization also decreased the cover and abundance of the natural vegetation; therefore, active revegetation is required to restore the natural vegetation and to conserve endangered and endemic species.

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Non-native tree species in the viewpoint of climate change

Šumarski list ◽

10.31298/sl.142.7-8.6 ◽

2018 ◽

Vol 142 (7-8) ◽

pp. 401-402

Author(s):

Martina Đodan ◽

Robert Brus ◽

Sanja Perić ◽

Kristina Pratasiene ◽

Milan Oršanić ◽

...

Keyword(s):

Climate Change ◽

Pseudotsuga Menziesii ◽

Tree Species ◽

Quercus Rubra ◽

Robinia Pseudoacacia ◽

Pinus Strobus ◽

Juglans Nigra ◽

Fraxinus Americana ◽

Native Tree ◽

Native Tree Species

Gospodarenje alohtonim vrstama ima tradiciju u hrvatskome šumarstvu, ali njihov potencijal se treba ponovno razmotriti i ocijeniti u novonastalim okvirima klimatskih promjena te rastućim potrebama društva za šumskim proizvodima i uslugama. Unatoč činjenici da svaka država ima svoj popis introduciranih vrsta, uključujući i Hrvatsku, autori prihvaćaju definiciju COST Akcije FP1403 NNEXT te rad baziraju na šumskim vrstama drveća kojima se prirodni areal nalazi izvan granica Europe. Ovaj pregledni rad doprinos je saznanjima o introdukciji i aktivnoj uporabi alohtonih vrsta u zemlji, a obuhvaća dostupne znanstvene i stručne studije te primjere uspješne uporabe u gospodarenju šumama. Zbog složenosti ove problematike autori će objaviti pregled rizika i izazova uporabe alohtonih vrsta u zasebnome radu. Dostupni podaci o prisutnosti alohtonih vrsta na pokusnim objektima te u šumarskoj praksi ukazuju kako se u praksi koristi tek manji broj vrsta (Tablica 1), dok su stvarni potencijal i njihove koristi daleko veće. Analiza podataka ukazuje kako su najzastupljenije alohtone vrste u šumarskoj praksi: Robinia pseudoacacia L. (12003.88 ha), Pinus strobus L. (3218.69 ha), Juglans nigra L. (2376.66 ha), F. pennsylvanica Marshall. i Fraxinus americana L.(1099.77 ha), Pseudotsuga menziesii (Mirb.) Franco. (393,05 ha) i L Quercus rubra. (51,99 ha). Podaci o proizvodnji šumskoga reprodukcijskog materijala navedenih vrsta ukazuje da rasadnička proizvodnja nije usklađena s potencijalom njihove uporabe u praksi. U radu se daje i iscrpan pregled različitih gledišta i koristi uzgoja alohtonih vrsta u Hrvatskoj. Samo neke od njih su (Slika 1, Tablica 2): nove mogućnosti proizvodnje visoko kvalitetnog drveta u kraćim ophodnjama, kao i drveta za bioenergiju, novih drvnih proizvoda i tehnologija; socijane koristi (mali i srednji poduzetnici, privatni šumoposjednici); povećanje stabilnosti i adaptabilnosti šumskih sastojina, ali samo u slučajevima velikih šteta i male plastičnosti i otpornosti domaćih vrsta; smanjenje intenziteta šumskouzgojnih radova, kao i uloženih sredstava na pripremi staništa prilikom pošumljavanja; ostvarivanje većih mogućnosti uporabe zapuštenoga poljoprivrednog zemljišta i ostalih prikladnih površina; sanacija progala ili većih površina nakon šteta u sastojinama domaćih vrsta (npr. obične smreke); supstitucija osjetljivih vrsta otpornijim i plastičnijim vrstama (mogućnosti mješovitih ili obogaćenih sastojina otpornijim alohtonim vrstama) te umanjenje negativnog djelovanja biotskih i abiotskih čimbenika. Njihova uporaba u sanaciji površina te konverziji degradiranih i devastiranih šuma pruža nove mogućnosti posebice na područjima s nepovoljnim ekološkim uvjetima, za koja se predviđa da će biti najpogođenija područja Hrvatske u budućnosti. Alohtone vrste mogu osigurati i niz opće korisnih funkcija šuma (npr. povećanje vezanja ugljika, fitoremedijacija zagađenih tala). Zbog složenosti problematike preporučujemo da se odluke o uporabi alohtonih vrsta donose na osnovi usporedbe s domaćim vrstama za svako stanište te na osnovi pregleda potencijalnih koristi, ali i rizika i izazova. Ističemo kako pojedine alohtone vrste treba poticati, dok neke zbog svoga invanzivnog potencijala trebaju biti strogo ograničene. Uporaba visokoproduktivnih, otpornijih i plastičnijih alohtonih vrsta predstavlja nova šumskouzgojna rješenja, koja su posebice važna u smislu pripreme staništa za prihvat autohtonih vrsta te povećanja otpornosti i plastičnosti šumskih sastojina, što je neizostavna komponenta adaptacijskih strategija gospodarenja šumama. Ipak, daljnja znanstvena istraživanja potrebna su kako bi se kvantificirala uporabljivost svake alohtone vrste, ali i olakšalo donošenje odluka u praksi.

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Climate resilience through natural regeneration in degraded natural forests of south-eastern hilly region of Bangladesh

Bangladesh Journal of Botany ◽

10.3329/bjb.v48i3.47720 ◽

2019 ◽

Vol 48 (3) ◽

pp. 417-425

Author(s):

Md Khayrul Alam Bhuiyan ◽

Md Akhter Hossain ◽

Abdul Kadir Ibne Kamal ◽

Mohammed Kamal Hossain ◽

Mohammed Jashimuddin ◽

...

Keyword(s):

Tree Species ◽

Natural Regeneration ◽

Diversity Indices ◽

Acacia Auriculiformis ◽

Quantitative Structure ◽

Natural Forests ◽

Climate Resilience ◽

Hilly Region ◽

Major Cluster ◽

Ecological Dominance

A study was conducted by using 5m × 5m sized 179 quadrates following multistage random sampling method for comparative regenerating tree species, quantitative structure, diversity, similarity and climate resilience in the degraded natural forests and plantations of Cox's Bazar North and South Forest Divisions. A total of 70 regenerating tree species were recorded representing maximum (47 species) from degraded natural forests followed by 43 species from 0.5 year 39 species from 1.5 year and 29 species from 2.5 year old plantations. Quantitative structure relating to ecological dominance indicated dominance of Acacia auriculiformis, Grewia nervosa and Lithocarpus elegans seedlings in the plantations whereas seedlings of Aporosa wallichii, Suregada multiflora and Grewia nervosa in degraded natural forests. The degraded natural forests possess higher natural regeneration potential as showed by different diversity indices. The dominance-based cluster analysis showed 2 major cluster of species under one of which multiple sub-clusters of species exists. Poor plant diversity and presence of regenerating exotic species in the plantations indicated poor climate resilience of forest ecosystem in terms of natural regeneration.

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Assessing Annual Actual Evapotranspiration Based on Climate, Topography and Soil in Natural and Agricultural Ecosystems

Climate ◽

10.3390/cli9020020 ◽

2021 ◽

Vol 9 (2) ◽

pp. 20

Author(s):

Kleoniki Demertzi ◽

Vassilios Pisinaras ◽

Emanuel Lekakis ◽

Evangelos Tziritis ◽

Konstantinos Babakos ◽

...

Keyword(s):

Water Balance ◽

Large Scale ◽

Hydrological Model ◽

Actual Evapotranspiration ◽

Irrigated Agriculture ◽

Climate Data ◽

Natural Ecosystems ◽

Loading Effects ◽

Very High ◽

Of Greece

Simple formulas for estimating annual actual evapotranspiration (AET) based on annual climate data are widely used in large scale applications. Such formulas do not have distinct compartments related to topography, soil and irrigation, and for this reason may be limited in basins with high slopes, where runoff is the dominant water balance component, and in basins where irrigated agriculture is dominant. Thus, a simplistic method for assessing AET in both natural ecosystems and agricultural systems considering the aforementioned elements is proposed in this study. The method solves AET through water balance based on a set of formulas that estimate runoff and percolation. These formulas are calibrated by the results of the deterministic hydrological model GLEAMS (Groundwater Loading Effects of Agricultural Management Systems) for a reference surface. The proposed methodology is applied to the country of Greece and compared with the widely used climate-based methods of Oldekop, Coutagne and Turk. The results show that the proposed methodology agrees very well with the method of Turk for the lowland regions but presents significant differences in places where runoff is expected to be very high (sloppy areas and areas of high rainfall, especially during December–February), suggesting that the proposed method performs better due to its runoff compartment. The method can also be applied in a single application considering irrigation only for the irrigated lands to more accurately estimate AET in basins with a high percentage of irrigated agriculture.

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The composition and diversity of natural regeneration of tree species in gaps under different intensities of forest disturbance

Journal of Forestry Research ◽

10.1007/s11676-020-01269-6 ◽

2021 ◽

Author(s):

Maame Esi Hammond ◽

Radek Pokorný ◽

Daniel Okae-Anti ◽

Augustine Gyedu ◽

Irene Otwuwa Obeng

Keyword(s):

Tree Species ◽

Natural Regeneration ◽

Forest Disturbance ◽

Forest Site ◽

Gap Formation ◽

Tree Species Composition ◽

Forest Sites ◽

Significant Difference ◽

Shade Tolerant Species ◽

Disturbed Forest

AbstractThe positive ecological interaction between gap formation and natural regeneration has been examined but little research has been carried out on the effects of gaps on natural regeneration in forests under different intensities of disturbance. This study evaluates the composition, diversity, regeneration density and abundance of natural regeneration of tree species in gaps in undisturbed, intermittently disturbed, and disturbed forest sites. Bia Tano Forest Reserve in Ghana was the study area and three gaps each were selected in the three forest site categories. Ten circular subsampling areas of 1 m2 were delineated at 2 m spacing along north, south, east, and west transects within individual gaps. Data on natural regeneration < 350 cm height were gathered. The results show that the intensity of disturbance was disproportional to gap size. Species diversity differed significantly between undisturbed and disturbed sites and, also between intermittently disturbed and disturbed sites for Simpson’s (1-D), Equitability (J), and Berger–Parker (B–P) indices. However, there was no significant difference among forest sites for Shannon diversity (H) and Margalef richness (MI) indices. Tree species composition on the sites differed. Regeneration density on the disturbed site was significantly higher than on the two other sites. Greater abundance and density of shade-dependent species on all sites identified them as opportunistic replacements of gap-dependent pioneers. Pioneer species giving way to shade tolerant species is a natural process, thus make them worst variant in gap regeneration.

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Stand Stability of Pure and Mixed-Eucalyptus Forests of Different Tree Species in a Typhoon-Prone Area

Forests ◽

10.3390/f12040458 ◽

2021 ◽

Vol 12 (4) ◽

pp. 458

Author(s):

Haiyan Deng ◽

Linlin Shen ◽

Jiaqi Yang ◽

Xiaoyong Mo

Keyword(s):

Tree Species ◽

Forest Restoration ◽

Large Scale ◽

Stand Structure ◽

Pinus Elliottii ◽

Stem Form ◽

Tree Species Composition ◽

Eucalyptus Plantation ◽

Mixed Plantation ◽

Preservation Rate

Background and Objectives: The stable stand structure of mixed plantations is the basis of giving full play to forest ecological function and benefit. However, the monocultural Eucalyptus plantations with large-scale and successive planting that caused ecological problems such as reduced species diversity and loss of soil nutrients have presented to be unstable and vulnerable, especially in typhoon-prone areas. The objective of this study was to evaluate the nonspatial structure difference and the stand stability of pure and mixed-Eucalyptus forests, to find out the best mixed pattern of Eucalyptus forests with the most stability in typhoon-prone areas. Materials and Methods: In this study, we randomly investigated eight plots of 30 m × 30 m in pure and mixed-Eucalyptus (Eucalyptus urophylla S. T. Blake × E. grandis W. Hill) plantations of different tree species (Neolamarckia cadamba (Roxb.) Bosser, Acacia mangium Willd., and Pinus elliottii var. Elliottii Engelm. × P. caribaea Morelet) on growth status, characterized and compared the distribution of nonspatial structure of the monoculture and mixtures, and evaluated the stand quality and stability from eight indexes of the nonspatial structure, including preservation rate, stand density, height, diameter, stem form, degree of stem inclination, tree-species composition, and age structure. Results: Eucalyptus surviving in the mixed plantation of Eucalyptus and A. mangium (EA) and in the mixed plantation of Eucalyptus and P. elliottii × P. caribaea (EP) were 5.0% and 7.6% greater than those in pure Eucalyptus plantation (EE), respectively, while only the stand preservation rate of EA was greater (+2.9%) than that of the pure Eucalyptus plantation. The proportions of all mixtures in the height class greater than 7 m were fewer than that of EE. The proportions of EA and mixed plantation of Eucalyptus and N. cadamba (EN) in the diameter class greater than 7 m were 10.6% and 7.8%, respectively, more than that of EE. EN had the highest ratio of branching visibly (41.0%), EA had the highest ratio of inclined stems (8.1%), and EP had the most straight and complete stem form (68.7%). The stand stability of the mixed plantation of Eucalyptus and A. mangium presented to be optimal, as its subordinate function value (0.76) and state value (ω = 0.61) of real stand were the largest. Conclusions: A. mangium is a superior tree species to mix with Eucalyptus for a more stable stand structure in the early growth stage to approach an evident and immense stability and resistance, which is of great significance for the forest restoration of Eucalyptus in response to extreme climate and forest management.

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Co-occurrences of tropical trees in eastern South America: disentangling abiotic and biotic forces

Plant Ecology ◽

10.1007/s11258-021-01143-3 ◽

2021 ◽

Author(s):

Emma-Liina Marjakangas ◽

Otso Ovaskainen ◽

Nerea Abrego ◽

Vidar Grøtan ◽

Alexandre A. de Oliveira ◽

...

Keyword(s):

South America ◽

Tree Species ◽

Large Scale ◽

Environmental Filtering ◽

Limiting Similarity ◽

Phylogenetic Relatedness ◽

Biogeographical Regions ◽

Dependent Processes ◽

Occurrence Of Species

AbstractSpecies co-occurrences in local communities can arise independent or dependent on species’ niches. However, the role of niche-dependent processes has not been thoroughly deciphered when generalized to biogeographical scales, probably due to combined shortcomings of data and methodology. Here, we explored the influence of environmental filtering and limiting similarity, as well as biogeographical processes that relate to the assembly of species’ communities and co-occurrences. We modelled jointly the occurrences and co-occurrences of 1016 tropical tree species with abundance data from inventories of 574 localities in eastern South America. We estimated species co-occurrences as raw and residual associations with models that excluded and included the environmental effects on the species’ co-occurrences, respectively. Raw associations indicate co-occurrence of species, whereas residual associations indicate co-occurrence of species after accounting for shared responses to environment. Generally, the influence of environmental filtering exceeded that of limiting similarity in shaping species’ co-occurrences. The number of raw associations was generally higher than that of the residual associations due to the shared responses of tree species to the environmental covariates. Contrary to what was expected from assuming limiting similarity, phylogenetic relatedness or functional similarity did not limit tree co-occurrences. The proportions of positive and negative residual associations varied greatly across the study area, and we found a significant tendency of some biogeographical regions having higher proportions of negative associations between them, suggesting that large-scale biogeographical processes limit the establishment of trees and consequently their co-occurrences.

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