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For centuries, coppice and coppice-with-standards were the main forest management systems in the northern and central parts of present Belgium. A high population density and a low forest cover in the whole region resulted in a high demand for wood, therefore strict regulations and management regimes were necessary to prevent overexploitation. We illustrate this with a well-documented case, that of Meerdaal Forest in Central Belgium, with reference to other sites in the region. Meerdaal Forest is a woodland 30 km east of Brussels. For centuries its high quality timber stands, especially oak, were managed as coppice-with-standards, with a gradually increasing share of standard trees. Using archive documents and ancient maps, we have reconstructed how this coppice-with-standard management has been developed and optimized over a period of about 500 years. Changes in cutting cycles and configurations were discerned, with a gradual increase of the importance of the standard layer over time. The analysis also showed how wood production could be successfully combined with other sources of income like grazing and pannage. We conclude that former managers of Meerdaal Forest, notwithstanding their lack of scholarship and reference works, developed a state-of-the-art sustainable and flexible management regime that allowed to provide high revenues during many centuries.

For many centuries, coppice-with-standards management was applied in the mixed oak stands of Meerdaal forest (Belgium). Over the last century, these stands were gradually converted to high forest. On an area of 20 ha, the coppice-with-standards management is being restored, with specific adaptations for biodiversity (conservation of dead wood and veteran trees). A survey of saproxylic beetles was performed at 8 locations in the forest, including one site within the coppice-with-standards restoration. This survey not only allowed an evaluation of the saproxylic beetle richness of the forest complex, but also made exploratory observations on the effect of this type of management, as compared to non-intervention, on species richness and composition of saproxylic beetles. The results show that the overall species richness in the forest complex was quite high and comparable to forest reserves in Germany. Both coppice-with-standards and high forest options appear to be equally species-rich, but consist of different communities, both containing specific, rare and notable species, with more thermophilous and light-demanding species in the coppice-with-standards plot. Based on these observations we suggest that a diversified management approach may be the most suitable to conserve and enhance diverse saproxylic beetle communities in formerly intensively managed semi-natural woodlands. This could include areas of active conservation management aimed at producing open-canopy stands with considerable amounts of sun-exposed deadwood, combined with areas of non-intervention in a matrix of multifunctional forests, where conservation of dead wood and veteran trees is fully incorporated in the management.

Metabolic disorders due to obesity and unhealthy lifestyle directly alter the oocyte's microenvironment and impact oocyte quality. Oxidative stress and mitochondrial dysfunction play key roles in the pathogenesis. Acute effects on the fully grown oocytes are evident, but early follicular stages are also sensitive to metabolic stress leading to a long-term impact on follicular cells and oocytes. Improving the preconception health is therefore of capital importance but research in animal models has demonstrated that oocyte quality is not fully recovered. In the in vitro fertilisation clinic, maternal metabolic disorders are linked with disappointing assisted reproductive technology results. Embryos derived from metabolically compromised oocytes exhibit persistently high intracellular stress levels due to weak cellular homeostatic mechanisms. The assisted reproductive technology procedures themselves form an extra burden for these defective embryos. Minimising cellular stress during culture using mitochondrial-targeted therapy could rescue compromised embryos in a bovine model. However, translating such applications to human in vitro fertilisation clinics is not simple. It is crucial to consider the sensitive epigenetic programming during early development. Research in humans and relevant animal models should result in preconception care interventions and in vitro strategies not only aiming at improving fertility but also safeguarding offspring health. Reduced oocyte quality, mainly due to mitochondrial dysfunction, is a key cause of subfertility in patients with metabolic diseases such as obesity. Recent fundamental understanding of the underlying mechanisms highlights the importance of developing effective preconception care strategies not only to improve metabolic health, but also oocyte quality. Minimising mitochondrial oxidative stress either in vivo or in vitro is a promising solution, however further investigations should consider the long-term consequences on epigenetic programming and offspring health. [ABSTRACT FROM AUTHOR]

The first life stages of a tree are subject to strong environmental stresses and competition, limiting their chances of survival. Establishing a mutualistic relationship with mycorrhizal fungi during early life stages may increase growth and survival rates of trees, but how mycorrhizal communities assemble during these stages remains unclear. Here, we studied variation in the ectomycorrhizal (EcM) fungal communities in the soil and roots of Fagus sylvatica seedlings and saplings. Fungal DNA was extracted from the soil and seedling and sapling roots collected in 156 plots across the beech-dominated Sonian forest (Belgium) and community composition was determined through metabarcoding. EcM fungal community composition significantly differed between soil, seedlings and saplings. Russula, Amanita and Inocybe were most abundant in soil, while Lactarius and Scleroderma were more abundant in seedling and sapling roots and Xerocomellus and Laccaria were most abundant in sapling roots. Our results provide evidence of partner turnover in EcM fungal community composition with increasing age in the early life stages of F. sylvatica.

Fertilisation of agricultural land causes an accumulation of nutrients in the top soil layer, among which phosphorus (P) is particularly persistent. Changing land use from farmland to forest affects soil properties, but changes in P pools have rarely been studied despite their importance to forest ecosystem development. Here, we describe the redistributions of the P pools in a four-decadal chronosequence of post-agricultural common oak (Quercus robur L.) forests in Belgium and Denmark. The aim was to assess whether forest age causes a repartitioning of P throughout the various soil P pools (labile P, slowly cycling P and occluded P); in particular, we addressed the time-related alterations in the inorganic versus organic P fractions. In less than 40 years of oak forest development, significant redistributions have occurred between different P fractions. While both the labile and the slowly cycling inorganic P fractions significantly decreased with forest age, the organic fractions significantly increased. The labile P pool (inorganic + organic), which is considered to be the pool of P most likely to contribute to plant-available P, significantly decreased with forest age (from >20 to <10% of total P), except in the 0-5 cm of topsoil, where labile P remained persistently high. The shift from inorganic to organic P and the shifts between the different inorganic P fractions are driven by biological processes and also by physicochemical changes related to forest development. It is concluded that the organic labile P fraction, which is readily mineralisable, should be taken into account when studying the bioavailable P pool in forest ecosystems.

Acidification of forest soils in Europe and North America has been an important concern over the last decades. The last area-covering survey of forest soil acidification in Flanders (North Belgium) goes back to 1985 [Ronse A, De Temmerman L, Guns M, De Borger R. Evolution of acidity, organic matter content, and CEC in uncultivated soils of North Belgium during the past 25 years. Soil Sci; 146, (1988), 453-460] and highlighted a significant acidification of the upper layer (0.3-0.4 m) of forested podzols during the period 1950-1985. The present study aimed to assess (1) to what extent further acidification of forested podzols occurred during the period 1985-2000 at different depths and (2) whether the average annual acidification rate accelerated or slowed down between 1985 and 2000 compared to the period 1950-1985. Average soil pH-KCl values of podzols in northern Belgium dropped during the period 1985-2000. This decline extends to a depth of about 50 cm but was most pronounced and significant in the A horizon. In the A(0), A(1) and A(2) horizons, average pH dropped with 0.2, 0.3 and 0.1 units, and in the B(ir) and C horizons with 0.1 units. No change in average pH value occurred in the B(h) horizon. Average annual acidification rate of the A(1) horizon was significantly higher in the period 1985-2000 than in the period 1950-1985. Changes in pH occurred in the entire soil profile during the period 1950/67-1985 likely because sulphate was the major form of acid deposition before 1985. After 1985, acid sulphur deposition decreased with more than 50% in North Belgium. In contrast, ammonium deposition almost doubled between 1950 and 1980, which may explain why soil acidification between 1985 and 2000 has been restricted to the upper soil horizons.