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1. Fires are nowadays small, yet frequent, in temperate Central European conifer forests, but little is known about the fire history in this region. This is likely due to the lack of intact forests that contain old trees and dead wood from which fire history may be reconstructed. An exception is the Białowieża Primeval Forest (BPF) in Poland for which we were able to reconstruct the fire history in detail. 2. From 886 tree ring samples collected in a 13-ha conifer-dominated area, we reconstructed fire events and tree establishment back to the mid 1600s. From 1653 to the late 1700s fires were very frequent, with mean point (single tree) fire intervals of 18 years and mean stand scale fire intervals of 6 years. After 1781, the intervals between the fires increased dramatically, and since 1874 no major fire was recorded. 3. Tree establishment underwent substantial changes, closely tracking shifts in fire frequency. When fires were frequent, Pinus sylvestris establishment occurred only sporadically. Later, less frequent fires promoted massive establishment of both P. sylvestris and Picea abies. At present, only P. abies and a few deciduous trees regenerate. 4. Synthesis. We present the first high-resolution fire history in the Central European temperate lowland forest area. The discovery of old P. sylvestris trees and stumps with fire scars in many conifer-dominated parts of BPF show that fire was a major component in the past dynamics of this forest. We also show that historically, fires were recurring at very close intervals, supporting an open, Pinus-dominated forest. These result contrasts with the written history of BPF, which focus on a few, large fires from the past. Human influence on the fire regime was probably substantial, although the disentangling of climatic and human impacts needs further studies. We propose that fire should be increasingly taken into consideration in models of disturbance, vegetation development and forest openness in the whole Central European lowland forest region.

QUESTIONS: What were the features of the historical forest fire regime, fire intensity in particular, in Pinus sylvestris‐dominated stands of Białowieża Forest? Did tree recruitment patterns relate to the fire history? LOCATION: Białowieża Forest, western Belarus and northeast Poland. METHODS: We used dendrochronological methods to reconstruct the fire regime in a 8.5‐ha mixed coniferous (Pinus sylvestris–Picea abies) forest stand located in the Belarusian part of Białowieża Forest. We analysed fire frequency at stand and point scale, seasonal distribution of fires and fire intensity. We compared the results to a previous study done in a 13.0‐ha site of similar habitat and stand structure, located in the Polish part of Białowieża Forest. RESULTS: We reconstructed fires back to 1655, the most recent fire dating to 1918. Mean fire interval at stand scale during 1645–2010 was 9 ± 7.8 yrs (±SD). Fire frequency gradually declined after 1811, with mean fire interval at stand scale increasing from 5 ± 2.5 yrs prior to 1811 to 18 ± 9.3 yrs thereafter. Most fires were likely of low intensity, as suggested by (1) small average tree diameter (5.1 ± 2.9 cm) at the first scar, (2) absence of strong negative growth reactions after fire, and (3) high fire frequency likely limiting fuel build‐up. However, a fire in 1718 was intense and resulted in a wave of P. sylvestris regeneration. The reconstructed fire history in the Belarusian part of Białowieża Forest showed many similarities with that done in the Polish section of this forest. Similarities included dominance of low‐intensity dormant and early‐season fires, sporadic occurrence of high‐intensity fires, high fire frequencies between the 1650s and the early 1800s, and cessation of fires since the early 20th century. Six out of 50 fire dates reconstructed in both sites were common and represented a level of synchrony that was significantly higher than expected under a random pattern of fire occurrence. CONCLUSIONS: Low‐intensity surface fires dominated the historical fire regime of Białowieża Forest. However, occasional high‐intensity stand‐replacing fires led to successional changes at the stand scale.

Questions: 1. Is the above-ground biomass in natural temperate forests positively correlated with tree species diversity? 2. Is this biomass related to the diversity of tree functional groups? Location: We used published data from over 100 permanent plots located in natural temperate forests in the Czech Republic, Poland and Slovakia. Methods: We related the number of tree species and Simpson's index of tree species diversity to the above-ground biomass in natural forest stands, and we repeated the same calculations for the identification of functional groups of trees using PCA analysis of functional traits. Results: Analysed sites ranged from almost pure subalpine spruce stands to mixed deciduous lowland forests with eight tree species per stand. The above-ground biomass accumulation ranged from 169 to 536 tons of dry mass per hectare. For the analysed data set the relationship between tree species diversity and biomass accumulation was not significant but showed a negative trend. Similar results were obtained in analyses employing tree functional groups instead of tree species. A significant negative relationship was found after four stands located in the highest elevations had been removed from the data set. Conclusions: There is a weak negative relationship between tree species diversity and above-ground biomass in natural forests of Central Europe. Nomenclature: Tutin et al. (1964–1980).

The biogeographic history of southern South America has led to a markedly distinct flora within the frame of the Neotropics, which is also particularly heterogeneous in terms of its eco-geographic distribution. This environmental complexity is at the base of the many and controversial classification systems that have been proposed for the vegetation of the so-called Cono Sur region (Paraguay, Chile, Argentina, Uruguay and parts of Brazil and Bolivia). In this study, we aimed to assess the floristic consistency of the main vegetation types that inhabit the region. Our dataset consisted of 116,130 occurrence records of 3662 species of shrubs and trees in 781 sampling sites spread over six countries and eight phytogeographic domains: Atlantic Forest, Pampa, Gran Chaco, Patagonia, Southern Andean, Mediterranean Chile, Temperate Pacific, and Pacific Islands. We performed a cluster analysis and nonmetric multidimensional scaling ordination analysis of this dataset followed by multi-response permutation procedures and permutational multivariate analysis of variance and taxonomic distinction index and indicator species. The greater differentiation took place among the phytogeographic domains and leaf flush regimes (evergreen, deciduous, and semideciduous) though there was also a remarkable latitudinal gradient. Our analyses showed that the pre-defined vegetation types were consistent in terms of woody flora composition and have a considerable number of indicators, many of which endemic. In terms of conservation prioritization, Atlantic Rain Forest therefore has importance because of its high species richness while temperate and mediterranean forests west of the Andes should not be ignored given that they show much higher endemism than would be expected given their species richness.

Coarse woody debris (CWD) may play a role in nutrient cycling in temperate forests through the leaching of solutes, including dissolved organic carbon (DOC) and dissolved organic nitrogen (DON), to the underlying soil. These fluxes need to be considered in element budget calculations, and have the potential to influence microbial activity, soil development, and other processes in the underlying soil, but studies on leaching from CWD are rare. In this study, we collected throughfall, litter leachate, and CWD leachate in situ at a young mixed lowland forest in NY State, USA over one year. We measured the concentrations of DOC, DON, NH₄⁺, NO₃⁻, dissolved organic sulfur,$\\text{SO}_{4}{}^{2-}$, Cl⁻, Al, Ca, K, Mg, Na, and P, estimated the flux of these solutes in throughfall, and measured the cover of CWD to gain some insight into possible fluxes from CWD. Concentrations of DOC were much higher in CWD leachate than in throughfall or litter leachate (15 vs. 0.7 and 1.6 mM, respectively), and greater than reported values for other leachates from within forested ecosystems. Other solutes showed a similar pattern, with inorganic N being an exception. Our results suggest that microsite scale fluxes of DOC from CWD may be An high relative to throughfall and litter leaching fluxes, but since CWD covered a relatively small fraction (2%) of the forest floor in our study, ecosystem scale fluxes from CWD may be negligible for this site. Soil directly beneath CWD may be influenced by CWD leaching, in terms of soil organic matter, microbial activity, and N availability. Concentrations of some metals showed correlations to DOC concentrations, highlighting the possibility of complexation by DOM. Several solute concentrations in throughfall, including DOC, showed positive correlations to mean air temperature, and fewer showed positive correlations in litter leachate, while negative correlations were observed to precipitation, suggesting both biological and hydrologic control of solute concentrations.

Cool temperate rainforest in Australia is commonly dominated by Nothofagus species. In Victoria and Tasmania, Nothofagus cunninghamii dominates old rainforest on optimal sites and is able to regenerate continuously. Size structure analysis of the major lowland tree species in this forest suggest that no major changes in species composition or dominance are occurring. This contrasts with the status of Nothofagus in lowland rainforest in New Zealand and rainforest below about 1 000 m a.s.l. in south-central Chile. N. cunninghamii is a relatively light-demanding species, and is maintaining its dominance by seedling regeneration in canopy gaps created by the death of old individuals. The dynamics of the cool temperate rainforest in northern New South Wales are more complex. These forests are dominated by Nothofagus moorei, and size structure analysis indicates that persistence of this species within the rainforest is dependent on vegetative regeneration. On some sites this rainforest is being actively invaded by warm temperate and sub-tropical elements from lower altitudes. In these areas N. moorei in unable to regenerate beneath the canopy.