Natural Forest Succession Research Articles

Climate warming-induced replacement of mesic beech by thermophilic oak forests will reduce the carbon storage potential in aboveground biomass and soil

Key messageClimate-warming related replacement of beech by oak forests in the course of natural forest succession or silvicultural decisions may considerably reduce ecosystem carbon storage of central European woodlands.ContextClimate warming may change the carbon (C) storage in forest biomass and soil through future shifts in tree species composition. With a projected warming by 2–3 K over the twenty-first century, silvicultural adaptation measures and natural succession might lead to the replacement of European beech forests by thermophilic oak forests in drought- and heat-affected regions of central and south-eastern Europe, but the consequences for ecosystem C storage of this species shift are not clear.AimsTo quantify the change in C storage in biomass and soil with a shift from beech (Fagus sylvatica) to oak forest (Quercus petraea, Q. frainetto, Q. cerris), we measured the aboveground biomass (AGC) and soil C pools (SOC).MethodsAGC pools and SOC stocks to − 100 cm depth were calculated from forest inventory and volume-related SOC content data for beech, mixed beech-oak and oak forests in three transects in the natural beech-oak ecotone of western Romania, where beech occurs at its heat- and drought-induced distribution limit.ResultsFrom the cooler, more humid beech forests to the warmer, more xeric oak forests, which are 1–2 K warmer, AGC and SOC pools decreased by about 22% (40 Mg C ha−1) and 20% (17 Mg C ha−1), respectively. The likely main drivers are indirect temperature effects acting through tree species and management in the case of AGC, but direct temperature effects for SOC.ConclusionIf drought- and heat-affected beech forests in Central Europe are replaced by thermophilic oak forests in future, this will lead to carbon losses of ~ 50–60 Mg ha−1, thus reducing ecosystem carbon storage substantially.

Microbial diversity regulates ecosystem multifunctionality during natural secondary succession

Abstract Natural forest succession after disturbances is one of the most important restoration strategies. However, the responses of ecosystem multifunctionality during natural forest succession remains poorly understood in forest ecosystem. Here we evaluated how the ecosystem multifunctionality including nutrient cycling, carbon stocks, water regulation, decomposition, wood production and symbiosis develops using a chronosequence, and identified the key factors contributing to the variations in the ecosystem multifunctionality during natural forest succession. We provide evidence that the ecosystem multifunctionality gradually increased along with succession stages. The individual functions of carbon stocks and water regulation also exhibited increasing patterns with stand development. The microbial diversity were more principal factors than plant diversity and soil properties for the explanation of changes in the ecosystem multifunctionality. The regression analysis showed that the diversity of bacteria, general fungi, actinomycetes, nematodes, G+ bacteria and G− bacteria significantly and positively associated with ecosystem multifunctionality. Soil nematodes exhibited significantly positive correlation with most of the individual functions. Synthesis and applications. Taken together, our results demonstrate that natural forest restoration plays a key role in promoting ecosystem multifunctionality, and emphasize the importance of soil microbial diversity for the maintenance of ecosystem functions and health.

The effects of land management patterns on soil carbon sequestration and C:N:P stoichiometry in sloping croplands in southern China

Excessive use of sloping soil in agriculture can result in loss of soil carbon (C) and stoichiometric imbalances, leading to soil degradation and a reduction in ecosystem services. Therefore, studying the effects of different utilization patterns on soil C stocks and stoichiometry is critical for the sustainable development of agriculture on uneven terrain. Here, we conducted a 7-year field study of cropland with a 10% slope, comparing soil C, nitrogen (N), and phosphorus (P) stocks and ratios between experimental plots of naturally abandoned land and different planting patterns (peanuts, daylily, oil tea planting with bare floor or inter-row coverage of straw, white clover or peanuts). We found that oil tea planting without inter-row coverage significantly lessened soil total C, microbial C and N, soil organic C, dissolved organic C, readily oxidizable C and available N compared with natural abandonment, whereas peanuts showed smaller differences, and daylily planting was most similar to natural abandonment. We also found that most planting patterns exacerbated soil C and P imbalance through the combination of C loss and P addition from fertilization. Our results show that inter-row coverage of straw or white clover can significantly alleviate these adverse influences. The atomic C:N and C:P ratios across all experimental plots were 5.10 ~ 30.5- and 0.675 ~ 8.13-fold lower, respectively, than the median values for Chinese soils, indicating that soil restoration or reasonable utilization has a high C sequestration potential, but it may be limited by P. These results suggest that perennial crops, such as oil tea with intercropping, can be nearly as effective as natural forest succession to reduce soil degradation on sloped farmland.

Decreases in soil P availability are associated with soil organic P declines following forest conversion in subtropical China

The large-scale conversion of natural forests to plantations profoundly alters the accumulation and transformation of soil nutrients. However, our understanding of how soil P responds to forest conversion is far from complete. This study aims to explore the changes in various soil P fractions associated with forest conversion in subtropical forest soils, where P is known to be relatively scarce. Soil samples were collected from an evergreen broad-leaved forest, a secondary forest, and two plantation forests. The soil properties, P fractions, amino sugars, and phosphatase activities were determined. The replacement of natural forests by plantation forests was associated with reductions in soil labile inorganic P (Pi) and organic P (Po), moderately labile Po, and total P. Soil amino sugars, which are indicative of historical populations of soil microbes, consistently decreased following forest conversion. We also found significant positive relationships between most P fractions and amino sugars content. A structural equation model suggested that Po, especially labile and moderately labile Po, were the potential sources of labile Pi. The positive relationship between labile Pi and acid phosphatase activity indicates that microbes are involved in soil P transformations by regulating P-hydrolytic enzymes activity. Overall, our work suggests that forest conversion significantly decreased most soil P fractions, including labile Pi, labile Po, and moderately labile Po, partly due to the declines in microbial populations that play an important role in releasing P from litter and root necromass. Organic P may play a vital role in sustaining P availability through organic P decomposition facilitated by microbial phosphatases, resulting in the release of labile P in the forest soils. These findings provide a mechanistic understanding of soil P cycling following forest conversion in low available P subtropical forests.

Evaluating Plantation Forest vs. Natural Forest Regeneration for Biodiversity Enhancement in Hong Kong

Global trends predict a continuous increase in the proportion of forest occupied by plantations up to the end of the 21st century, while a dramatic loss of biodiversity is foreseen as a result of anthropogenic exploitation and climate change. This study compares the role and performance of plantation policies in Hong Kong, with natural regeneration of secondary forest, using detailed spatio-temporal data extracted from a previous study. The study extends over a 70-year period from 1945 to 2014 using aerial photographs and satellite images of five time periods to document spatio-temporal trends in plantation forestry and natural forest succession. Field data on species richness and woody biomass at different stages of forest succession are compared with available data from plantations in the same study area. Results indicate that plantation forests support relatively few native species in the understory, with much lower species richness than naturally regenerated forest, even after 6 to 7 decades. Time-sequential maps of habitat change show that natural forest succession from barren grassy hillsides, progressed at an annual rate of 7.8%, from only 0.2% of the landscape post WWII, to over 37% today. Plantation forestry on the other hand has been less successful, and has even acted as a barrier to natural forest regeneration, as mono-cultural plantations from the late 1960s to 1980s are still plantations today, whereas other similar areas have succeeded naturally to forest. The theory of plantations acting as a nurse crop for a woody native understory is not supported, as Pinus massoniana plantations, destroyed by two deadly nematodes during the 1970s, apparently had no woody understory, as they were seen to have reverted to grassland in 1989 and are still mainly grassland today.

Diversity pattern of bats (Mammalia: Chiroptera) in a modified tropical environment in the western region of Cameroon

The western region of Cameroon is one of the leading agricultural production areas in sub-Saharan Africa, and this ongoing anthropogenic perturbation has led to the replacement of natural forests with agroecosystems. Such anthropogenic landscape transformations may have affected bat species composition and abundance in the area. Our study assessed the response of bat assemblages to these changes, by comparing species diversity and abundance across four distinct habitat types within the region: cultivated farms (transformed landscape), savannah and gallery forest (both representing degraded areas), and secondary forest. A total of 442 individuals assigned to 25 species were captured using ground-level mist nets. The cultivated farms recorded the highest bat species richness (13 species) and abundance (145 individuals), whereas the gallery forest had the lowest species richness (six species) and abundance (62 individuals). Myonycteris angolensis had the highest relative abundance in the region, with large numbers captured in cultivated farms. According to the rank-frequency diagram, bat assemblages in cultivated farms (Akaike’s Information Criterion (AIC) = 53.7), gallery forest (AIC = 27.7), and secondary forest (AIC = 48.5) are distributed according to the pre-emption model, whereas the distribution in the savannah (AIC = 40.0) follow the null model. Generalised linear models revealed significant differences in species and relative abundance across the four habitat types.

Intestinal Helminths in Wild Rodents from Native Forest and Exotic Pine Plantations (Pinus radiata) in Central Chile.

Simple SummaryLand-use changes are one of the most important drivers of zoonotic disease risk in humans, including helminths of wildlife origin. In this paper, we investigated the presence and prevalence of intestinal helminths in wild rodents, comparing this parasitism between a native forest and exotic Monterey pine plantations (adult and young plantations) in central Chile. By analyzing 1091 fecal samples of a variety of rodent species sampled over two years, we recorded several helminth families and genera, some of them potentially zoonotic. We did not find differences in the prevalence of helminths between habitat types, but other factors (rodent species and season of the year) were relevant to explain changes in helminth prevalence. Given that Monterey pine plantations are one of the most important forestry plantations worldwide, and due to the detection of potentially zoonotic helminths, more research should be conducted in this study area and elsewhere in order to better understand the effect of pine plantations on parasites and pathogens in rodents and other wildlife hosts.Native forests have been replaced by forestry plantations worldwide, impacting biodiversity. However, the effect of this anthropogenic land-use change on parasitism is poorly understood. One of the most important land-use change in Chile is the replacement of native forests by Monterey pine (Pinus radiata) plantations. In this study, we analyzed the parasitism (presence and prevalence) of intestinal helminths from fecal samples of wild rodents in three habitat types: native forests and adult and young pine plantations in central Chile. Small mammals were sampled seasonally for two years, and a total of 1091 fecal samples from seven small mammal species were analyzed using coprological analysis. We found several helminth families and genera, some of them potentially zoonotic. In addition, new rodent–parasite associations were reported for the first time. The overall helminth prevalence was 16.95%, and an effect of habitat type on prevalence was not observed. Other factors were more relevant for prevalence such rodent species for Hymenolepis sp. and season for Physaloptera sp. Our findings indicate that pine plantations do not increase helminth prevalence in rodents compared to native forests.

Analysis on the influence of runoff trend in the Liusha River Basin of Xishuangbanna

In recent decades, there are lots of the changes of land use in the Liusha River basin in Xishuangbanna, Yunnan Province. The large-scale replacement of natural forests by rubber plantation have had a certain impact on the ecological environment and water resources in the Liusha River basin. Based on the data of runoff, rainfall and evaporation from 1963 to 2015 measured by Menghai Hydrological Station of Liusha River, the effects of climate change and human activities on the ecological environment of Liusha River runoff and the degree of change were analyzed by using the comparison method of slope change rate of runoff accumulation. The research results show that the cumulative amount of runoff flow after mutation presents significant decrease trend from 1963 to 2015. Because of the Liusha river runoff change decision which residents downstream watershed water security, the runoff of the ecological environment situation and analysis, the protection of natural resources such as forests and the effective protection of regional water resources sustainable development has important guiding significance.

Hydrological and productive impacts of recent land‐use and land‐cover changes in the semiarid Chaco: Understanding novel water excess in water scarce farmlands

AbstractOver the last decades, the rapid replacement of native forests by crops and pastures in the Argentinean semiarid Chaco plains has triggered unprecedented groundwater level raises resulting from deep drainage increases, leading to the first massive waterlogging event on records (~25,000 Ha flooded in 2015 near Bandera, one of the most cultivated clusters of the Chaco). In this paper, we link this episode to the ongoing deforestation and cropping scheme shifts through the combined analysis of remote sensing data, agricultural surveys, local farmer information and hydrologic modelling. From 2000 to 2015, the agricultural area of Bandera increased from 21% to 50%, mostly at the expense of dry forests. In this period, agriculture migrated from more intensive (i.e., double‐cropping) to more water‐conservative (i.e., late‐summer single crops) schemes as a general strategy to reduce drought risks. These changes reduced regional evapotranspiration and increased the intensity of deep drainage in wet years. Contrasting cropping schemes displayed significant evapotranspiration differences, but all of them experienced substantial drainage losses (~100–200 mm) during the wettest year (2014/2015), suggesting that cropping adjustments have a limited capacity to halt the generation of water excesses. Nearly 50% of the cropped area in Bandera could not be sown or harvested following the groundwater recharge event of 2014/2015. In the ongoing context of shallow and rising water tables, the introduction of novel cropping schemes that include deep‐rooted perennials, to promote transpirative groundwater discharge, seems crucial to avoid the recurrence of water excesses and their associated dryland salinity risk in the region.

Advance of Urochloa decumbens (Stapf) R.D. Webster (Poaceae) on remaining native forest in the Serra da BODOQUENA NATIONAL PARK

The replacement of native forest by exotic grasses for pasture formation is a process that involves habitat destruction followed by the introduction of invasive alien species. The Serra da Bodoquena National Park covers an area of 77,021.58ha, comprising natural forests and remnants of abandoned pastures, which represent a threat to local biodiversity conservation. This study analyzed the dynamics of Urochloa decumbens–dominated matrix on remnants of native Deciduous Seasonal Forest within the Park, over 35 years, using satellite images, evaluating natural regeneration trend. The Urochloa matrix covers 1,268.9 (36.9%) of the 3,434.50 hectares study area. Our results indicate that the Urochloa matrix expanded over the native forest remnants, likely due to the occurrence of fire close to the forest edges, which may help natural regeneration failing. 8 months after a fire in 2013, the area of the grass-dominates matrix was found to replace 203.1 hectares over the forest. In this context, restoration actions are demanded, especially those that target fire control.

Thermal niche helps to explain the ability of dung beetles to exploit disturbed habitats

In terrestrial ecosystems, insects face a wide range of temperatures among habitats and time; consequently, the thermal niche is one of the main determinants of habitat selection and temporal patterns of activity. The replacement of native forests changes micro-climatic conditions and reduces the diversity of dung beetles; however, the physiological mechanisms behind these changes are not clear. We explore the role of the thermal niche in dung beetles to explain the ability of native species to exploit human-created habitats. Using infrared thermography, we measured variables associated with the thermal niche in 17 native species and used linear mixed-effects model and ANOVAs to compare disturbed habitats and the native forest. Endothermy and body mass explained the ability of dung beetles to exploit human-created open habitats. Small and diurnal species with very low endothermy were able to exploit deforested open habitats; evening/nocturnal/crepuscular species showed similar body mass and high endothermy in all habitats. Regarding thermoregulation mechanisms, none of the species (except one) showed defined or efficient mechanisms of physiological thermoregulation. In view of the accelerated process of forest replacement and climate change, a more profound understanding of the physiological requirements of species is essential to predict and mitigate future extinctions.

Carbon assimilation, water consumption and water use efficiency under different land use types in subtropical ecosystems: from native forests to pine plantations

The effects of selective logging in Argentinean native subtropical forests or its replacement by pine plantations on carbon and hydrological cycles is of importance for developing strategies for a sustainable use of water resources and climate mitigation in subtropical humid regions. Ecosystem-level gross primary productivity (GPP), evapotranspiration (ET) and water use efficiency (WUE) were assessed using multi-temporal MODIS remote sensing data and its response to climatic variables were analyzed in well-preserved native forests, degraded native forests by selective harvesting and pine plantations. Field measurements of leaf area index (LAI), tree density, basal area, tree high, diameter at breast height and understory cover was implemented. The GPP was high throughout the year across all three-land use types. Selective harvesting of commercial trees resulted in a significant decrease in tree density and in basal area compared to well-preserved native forests but did not have a negative impact on GPP. Mean annual ET was similar between both native forests because although the degraded forest had a lower tree density they had a greater maximun DBH per tree than the well-preserved forests and therefore high transpiration. The WUE was similar across the ecosystem types. Removal of 5.5 m2 of canopy trees produced a compensatory change in ecosystem structure and function resulting in the maintenance of GPP and ET. Replacement of native forests by pine plantations for wood production did not change annual GPP compared to native forests, but the final carbon assimilation should be lower due to the CO2 released before canopy closure and after harvesting. All climatic variables were linearly and significantly related to monthly GPP, ET and WUE with the exception of precipitation with monthly GPP. Finding forest management techniques for increasing carbon assimilation is of importance for limiting the rise of global CO2 emissions and for regulation of the water cycle.

Rewilding clearcuts: shrub vegetation as a facilitator of movement of a forest specialist

Replacement of native forests by exotic monoculture plantations is the principal driver of land change in central Chile; it reduces the richness and abundance of native mammals. The presence of shrub vegetation in mature pine plantation enhances habitat quality for small mammals. However, the role of structural complexity of shrub vegetation in young pine plantations after clearcutting remains unknown. Since plantations are managed by clearcutting, young pine plantations act as a barrier to movement of forest species. We tested if shrub vegetation contributes to rewilding harvested areas, assessing the movements of the long-haired field mouse (Abrothrix longipilis), a forest rodent, from native forest or mature pine plantations into young pine plantations. We evaluated habitat use at the edge of contrasting habitats, young pine plantations, and native forest or mature pine plantations. Habitat use was higher in young plantations that have shrub vegetation than those that have no shrubs. The long-haired field mouse is willing to use young plantations when shrub vegetation is developed.

Carbon-nitrogen isotope coupling of soil organic matter in a karst region under land use change, Southwest China

The soil stable carbon (C) and nitrogen (N) isotopes are widely used to indicate C3/C4 vegetation history, N sources and transformation processes, respectively. However, land use change, particularly converting forest into farm land, alters soil organic matter (SOM) sources and processes in soils, resulting in a hard understanding of soil C and N fate. In the present study, soil organic carbon (SOC) and soil organic nitrogen (SON) contents, and their stable isotope compositions (δ13C and δ15N) were determined in the five soil profiles under land use change (i.e., conversion of native forest land into shrub land, grass land, maize field, and paddy land) in Lobo county, Guizhou province, Southwest China. A coupling of 13C and 15N isotope in SOM under land use change was verified whether it could provide more accurate indications of sources and transformation processes.The SOC and SON contents of native forest land at the 0∼20 cm depth were significantly larger than these under other transformed lands. The SOC and SON contents decreased exponentially with increasing soil depth under all land use types, and showed opposite trends with soil pH. The C/N ratios of SOM in the soils under undisturbed native forest decreased from 10 to 7 with increasing soil depth, while an irregular fluctuation along soil profile was shown in other transformed lands. Similarly to the most study in the soils under C3 forest, the δ13C and δ15N values of SOM in the soils under native forest at the 0∼50 cm depth increased with increasing soil depth, with the range of −27.7‰∼−25.7‰ and 6.5‰∼10.0‰, respectively. While decreasing trends of them in the soils below 50 cm depth were attributed to the mixing of 13C and 15N-depleted organic matters from bedrocks. However, the δ13C and δ15N values of SOM along the soil profiles under other transformed lands were intensively irregularly fluctuated between −29.1‰ and −19.0‰, 1.2‰ and 7.9‰, respectively. The single δ13C and δ15N signals in the soil profiles of transformed lands indeed revealed the alterations of historical C3/C4 composition and N transformation processes after land use change, but these indications were not specific. The result of the coupling of 13C and 15N isotope under native forest land reveals a positive relationship between them, which associated with full plant-absorption against 15N-depleted inorganic nitrogen derived from SOM mineralization. This study suggests that the coupling of CN isotope fractionation more likely occurs in the C3 forest ecosystem with high N utilization efficiency. However, the replacement of native forest by farm land or grass land will reduce soil N utilization efficiency.

A combined approach to establishing the timing and magnitude of anthropogenic nutrient alteration in a mediterranean coastal lake- watershed system

Human activities have profoundly altered the global nutrient cycle through Land Use and Cover Changes (LUCCs) since the industrial revolution and especially during the Great Acceleration (1950 CE). Yet, the impact of such activities on terrestrial and aquatic ecosystems above their ecological baselines are not well known, especially when considering the response of these systems to the intensity of LUCCs on nutrient cycles. Here, we used a multiproxy approach (sedimentological, geochemical and isotopic analyses, historical records, climate data, and satellite images) to evaluate the role that LUCCs have on Nitrogen (N) cycling in a coastal mediterranean watershed system of central Chile over the last two centuries. Despite long-term anthropogenic use (agriculture, cattle grazing) in the Matanzas watershed– lake system, these LUCC appear to have had little impact on nutrient and organic matter transfer since the Spanish Colonial period. In contrast, the largest changes in N dynamics occurred in the mid-1970s, driven by the replacement of native forests and grasslands by government-subsidized tree plantations of introduced Monterey pine (Pinus radiata) and eucalyptus (Eucalyptus globulus). These LUCC had major impacts on the transfer of organic matter (which increased by 9.4%) and nutrients (as revealed by an increase in total N) to Laguna Matanzas. Our study shows that the presence of anthropogenic land use/cover changes do not necessarily alter nutrient supply and N availability per se but rather it is the magnitude and intensity of such changes that produce major impact on these processes in these mediterranean watersheds.

Succession from meadow to mature forest: Impacts on soil biological, chemical and physical properties—Evidence from the Pieniny Mountains, Poland

Long-term human agricultural activity in the Carpathian region created meaningful landscape transformations; for example, valuable and high-biodiversity, semi-natural areas were formed. Subsequently, socioeconomic changes after World War II started a trend of decreasing agricultural activity and pasturing, as well as the abandonment of higher-altitude and more-difficult-to-access meadows. As a result, in many cases, landscape transformation, such as secondary forest succession, began to occur. This study examined the influence of natural forest succession by comparing a semi-natural meadow to a 25-year-old forest succession area and an old-growth forested area, taking into account selected soil physical, chemical and biological properties. The study sought to answer the following questions: where are the greater carbon stocks found — in meadows, forest successions or old-growth forests?; does soil microbial activity change during succession?; and does succession cause changes in soil physical properties? The research area was located in Pieniny National Park in southern Poland. No significant differences in the amount of carbon stock or the microbial activity (i.e. microbial biomass carbon content and dehydrogenase activity) were found among the meadow, succession and old-growth forest soil samples. However, the old-growth forest soils showed a much higher invertase activity than the succession and meadow soils. Nevertheless, when we took into consideration variables associated with the microbial properties, and placed these into an ordination space, more visible differences among the meadow, succession and forest samples became apparent. Thus, any discussion of land use in mountainous areas should take multiple aspects into account.

The effects of forestry and agroforestry plantations on bird diversity: A global synthesis

AbstractThe increasing expansion of productive lands around the world during the last decades constitutes a strong driver of biodiversity loss, as they are usually established near to high diversity areas. Despite many studies that have compared bird diversity between natural and productive systems, a global synthesis is still missing and important for understanding how biodiversity is being altered. We conducted a meta‐analysis based on 144 case studies to assess the effects of four types of plantations (forestry, oil palm, coffee, and cacao) on bird species richness and abundance. We examined those effects in function of plantation type, latitudinal zone (temperate or tropical), geographical context (mainland or island), zoogeographic zone, and biodiversity hotspots. Plantations presented negative effects on both bird species richness and abundance. Oil palm plantations showed more negative effects followed by forestry plantations, whereas coffee and cacao agroforestry plantations had no significant effects. Those effects were geographically variable, being more pronounced in islands and temperate zones, as well as at the Oriental, Palearctic, and Neotropical zoogeograghic regions, and at the Sundaland and Mediterranean Basin biodiversity hotspots. Our results showed that productive systems reduce both species richness and abundance of bird species, being insular species particularly susceptible. Exotic monocultures with low structural heterogeneity (e.g., oil palm plantations) derive in highly impoverished bird communities dominated by generalist species. We identified South East Asia, tropical South America, and the Mediterranean Basin as the most threatened regions because of the sensitivity of their bird communities and the increasing rates of native forest replacement.

Piloting restoration initiatives in subtropical scrub forest: specifying areas asserting adaptive management.

Subtropical scrub forests in Pakistan have diminished by about 75% over the last hundred years, mainly due to indiscriminate exploitation and invasion by exotics species. Lack of initiatives, awareness, and research in utilizing the techniques used for accelerating natural forest succession is resulting in further degradation of the remaining forests. To promote active restoration with local communities and governmental authorities, a restoration scheme was piloted between 2010 and 2016 to examine enrichment population effects. Over 4,000 saplings of two woody climax species, Acacia modesta and Olea ferruginea, raised from seeds of local provenance, were planted in three subjectively selected trial plots representing various stages of degradation, covering a total area of about 4ha. The results showed an overall 46% survival rate, accompanied by natural regeneration. Comparative analyses of the trial plots have shown variations which were strongly site specific, in addition, it also helped in gauging compliance of the site coordinators in implementing restoration measures as an effective management tool. This study provided an opportunity to appreciate the differences in terms of interventions used for implementing ecological restoration across landscape in the degraded scrub forests.

Effect of planting alien Robinia pseudoacacia trees on homogenization of Central European forest vegetation

Biological homogenization is a process of biodiversity loss driven by the introduction and invasion of widespread species and the extinction of specialized, endemic species. This process has accelerated in recent years due to intensive human activities. We focused our study on large areas of forest vegetation that have not yet been intensively studied. Forest management, especially the planting of alien trees, could play a key role in the homogenization process because alien trees can act as habitat ‘transformers’ influencing vegetation through creating different environmental conditions. Several types of native forests (hardwood floodplain forests, oak forests, and oak-hornbeam forests) have in many regions been replaced by Robinia pseudoacacia plantations. The huge diversity of native broadleaved deciduous forests in the Pannonian and Carpathian regions, with many local differences and considerable geographical variability, could be exposed to the homogenization process due to the planting of Robinia pseudoacacia. We used 282 paired plots of Robinia pseudoacacia-dominated forests and native forests with a distance of 50–250 m among them under the same environmental conditions to avoid the influence of the variability of local environmental conditions on the forest undergrowth. We found out that the replacement of native forests by plantations of Robinia pseudoacacia plays a crucial role in the homogenization process in forest vegetation by unifying microenvironmental conditions of stands and removing the geographically specified variability of plant communities from previous four classes to single one. The replacement reduced total species pool from 422 to 372 species and supported the occurrence of widespread, generalist plant species in the undergrowth.

Contrasting vegetation change (1974–2015) in hedgerows and forests in an intensively used agricultural landscape

AbstractQuestionsHow did hedgerows and forests change in area between 1974 and 2015 and did hedgerows still show the same vegetation composition in 2015? To what degree did the vegetation change in hedgerows and how do these changes compare to changes in forests? What is the nature of the species that changed and, from these, can we make general inferences about possible drivers of change?LocationThe countryside in the municipality of Turnhout, province of Antwerp, northern Belgium.MethodsThrough a resurvey of 54 and 20 quasi‐permanent plots in hedgerows and forests, respectively, we investigated shifts in the herb layer over the period 1974–2015. The plot‐level mean Ellenberg Indicator Values (EIVs) were calculated and soil samples were taken in 2015. We compared diversity statistics and used used Generalized Linear Mixed‐Effects Models (GLMMs) to detect trends in species richness (SR) and EIVs. Via a non‐metric multidimensional scaling (NMDS) ordination based on the Sørensen dissimilarity, we compared shifts at the community level.ResultsOur study shows severe, but opposite changes in SR in forests and hedgerows. In forests, SR declined and a homogenization occurred. The shifts in EIVs indicate that forest vegetation evolved to more shade‐tolerant and nutrient‐demanding species, likely due to eutrophication combined with natural forest succession. In hedgerows, SR significantly increased. The species pool became more diverse and more heterogeneous. Changes in EIVs suggest a change towards more light‐demanding species, possibly caused by fragmentation of the network, and towards species indicative for nutrient‐rich habitats, benefiting from eutrophication.ConclusionsIn general, SR in hedgerows is higher than in forests in our studied region, being a suitable habitat for a wide range of plant species in the countryside. However, the loss of almost 30% of the hedgerow habitat in 41 years confronts us with the challenge of protecting the hedgerow remnants, in the interest of agro‐biodiversity.