20 research outputs found

    Legacy of pre-disturbance spatial pattern determines early structural diversity following severe disturbance in mountain spruce forests in Czech Republic

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    Background Severe canopy-removing disturbances are native to many temperate forests and radically alter stand structure, but biotic legacies (surviving elements or patterns) can lend continuity to ecosystem function after such events. Poorly understood is the degree to which the structural complexity of an old-growth forest carries over to the next stand. We asked how predisturbance spatial pattern acts as a legacy to influence post-disturbance stand structure, and how this legacy influences the structural diversity within the early-seral stand. Methods Two stem-mapped one-hectare forest plots in the Czech Republic experienced a severe bark beetle outbreak, thus providing before-and-after data on spatial patterns in live and dead trees, crown projections, down logs, and herb cover. Results Post-disturbance stands were dominated by an advanced regeneration layer present before the disturbance. Both major species, Norway spruce (Picea abies) and rowan (Sorbus aucuparia), were strongly self-aggregated and also clustered to former canopy trees, predisturbance snags, stumps and logs, suggesting positive overstory to understory neighbourhood effects. Thus, although the disturbance dramatically reduced the standÔÇÖs height profile with ~100% mortality of the canopy layer, the spatial structure of post-disturbance stands still closely reflected the pre-disturbance structure. The former upper tree layer influenced advanced regeneration through microsite and light limitation. Under formerly dense canopies, regeneration density was high but relatively homogeneous in height; while in former small gaps with greater herb cover, regeneration density was lower but with greater heterogeneity in heights

    Phenological gap in fruiting period and dispersal of seeds from alien fleshy-fruited plants by medium-sized carnivores in temperate forests of Central Europe

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    Some biological differences between native and alien plants are relevant to their dispersal mechanisms. One of them is the fruiting period: it is shifted in time, peaking later than in natives. Here we report the case study showing the temporal distance in fruiting phenology between native and alien plants and their seed dispersal via carnivorous mammals. From 2009 to 2011, scats of badgers Meles meles, foxes Vulpes vulpes, martens Martes spp. (M. martes and M. foina) and possibly also raccoon dogs Nyctereutes procyonoides (N = 820) were collected along transects totaling 30.4 km in length each month from June to November. We analyzed the frequency of occurrence of seeds (FO%) and the seed load in sampled scats; 61.7% of the sampled feces contained seeds of 18 fleshy-fruited native and alien plant taxa, and the most abundant seeds were from species with multi-seeded fruits such as Vaccinium myrtillus (94.6%), Rubus sp. (2.0%), and drupes of Prunus serotina (1.0%). The structure of dominance was characterized by seeds of Vaccinium myrtillus (15.0%), Pyrus sp. (14.8%) and Prunus serotina (13.0%) with aliens reaching high frequency of occurrence (FO%). The shares of seed FO% in the samples differed between alien and native plants. For seed load there were also significant interactions between the status of the seeds (alien or native) and the month of the vegetation period. Our data show the coincidence of two factors ÔÇô the late fruiting period of alien plants and the decreasing availability of native fruits during the vegetation period. Such a set of factors may promote the dispersal of alien plant seeds by carnivorous mammals, which, unlike migrating birds, are constantly present in autumn. The limited availability of native fruits after their fruiting period, creating a phenological gap, makes alien plants the main source of fleshy-fruits at the end of vegetation period in forest ecosystems; this is expressed in high proportion of alien plants in seed FO%, and in significant interactions in the seed load in carnivore scats

    Contoura Vision ÔÇô the most personalised laser vision correction technique

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    Spersonalizowane zabiegi laserowej korekcji wad wzroku stanowi─ů kolejny stopie┼ä rozwoju chirurgii refrakcyjnej. Ich pocz─ůtki datuje si─Ö na koniec lat 90. ubieg┼éego wieku. Personalizacja zabieg├│w jest mo┼╝liwa dzi─Öki profilom ablacji wyznaczanym na podstawie analizy czo┼éa fali (aberrometrii) uk┼éadu optycznego oka lub map topograficznych rog├│wki. Obecnie metoda analizy czo┼éa fali (wavefront-guided), zale┼╝na od wielu zmiennych, ust─Öpuje miejsca technice opartej na topografii rog├│wki (topography-guided). Szczeg├│lnym rodzajem spersonalizowanej procedury (dla oczu operowanych po raz pierwszy) wykorzystuj─ůcej topografi─Ö rog├│wki jest ContouraTM VisionPersonalised laser vision correction procedures are the next step in refractive surgery development. They date back to the late nineties of the twentieth century. Customized ablation treatments are based on wavefront analysis of the optical system of the eye (aberrometry) or on corneal topographical maps. Nowadays, topography-guided custom ablation treatment supersedes the wavefront-guided technique, which is affected by more variables in the eye anatomy. The topography-guided procedure for virgin eyes is called ContouraTM Vision

    Data from: Non-trophic plant-animal interactions mediate positive density dependence among conspecific saplings

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    Trophic plant-animal interactions (e.g. browsing by ungulates, insect attack) are an important and well-studied source of mortality in many tree populations. Non-trophic tree-animal interactions (e.g. deer antler rubbing) also frequently lead to tree death, and thus have significant effects on forest ecosystem functioning, but they are much less well studied than trophic interactions are. As deer populations have increased in recent decades in the Northern Hemisphere, their impact on tree populations via browsing and antler rubbing will increase. The aim of the study was to illustrate the potential ability of non-trophic plant-animal interactions to regulate the dynamics of a natural forest. Specifically, we wanted to determine whether and how density and distance-dependent processes affect sapling mortality caused by an antler rubbing by red deer (Cervus elaphus). We used a spatially explicit approach to examine density and distance-dependent mortality effects in almost two thousand Picea abies saplings over 20 years, based on a fully mapped permanent 14.4 ha plot in a natural subalpine old-growth spruce forest. Antler rubbing by deer was the main identified cause of sapling mortality, and it showed a strong spatial pattern: positive density dependence of survival among spruce saplings. Deer selectively killed spruce saplings that were isolated from conspecifics. In consequence, non-trophic plant-deer interactions were a major driver of the spatial pattern of P. abies sapling survival. The other mortality causes (e.g. breaking, overturning) did not show density-dependent patterns or their effects were much weaker. In the medium and long term, the density-dependent pattern of sapling mortality due to antler rubbing can alter the tree stand structure. Our results highlight the ecological relevance of non-trophic plant-animal interactions for forest ecosystem functioning

    SPPA of Picea abies mortality

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    The file consists of four sheets which present SPPA of mortality (p11{r}; p12{r} and g1,1+2 - g2,1+2 {r}) in years 1993-2013, 1993-2003 and 2003-2013:(1) overall mortality; (2) deer-caused mortality; (3) mortality due to mechanical causes and (4) mortality of unknown causes

    Stand Composition, Tree-Related Microhabitats and BirdsÔÇöA Network of Relationships in a Managed Forest

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    Forest ecosystems contain many tree-related microhabitats (TreMs), which are used by various groups of organisms. Birds use TreMs for shelter, foraging and breeding. The abundance and variability of TreMs is related to tree stand composition and age. Over the last few centuries there has been a drastic decline in the structural and biological diversity of temperate forests over large areas of the Northern Hemisphere. These changes have reduced the diversity and quantity of TreMs. In this study we showed the relationships between stand composition, the abundance of TreMs, and the species richness of birds in a managed forest. We focused on TreMs that are important to birds: woodpecker breeding cavities, rot holes, dead branches, broken treetops, and perennial polypores. Our study was performed in a managed lowland temperate forest. In 94 plots (10 ha each) we made bird surveys and inventoried the stand composition and TreMs. Our results show that the tree stand composition of a managed forest affects the abundance of TreMs. The share of deciduous trees in the stand favors the occurrence of such TreMs as dead branches, rot holes and perennial polypores. The overall richness of bird species and the species richness of primary cavity nesters depended on the total basal area of oak, hornbeam and birch, whereas the species richness of secondary cavity nesters increased with the total basal area of birch and oak

    Stand Composition, Tree-Related Microhabitats and Birds—A Network of Relationships in a Managed Forest

    No full text
    Forest ecosystems contain many tree-related microhabitats (TreMs), which are used by various groups of organisms. Birds use TreMs for shelter, foraging and breeding. The abundance and variability of TreMs is related to tree stand composition and age. Over the last few centuries there has been a drastic decline in the structural and biological diversity of temperate forests over large areas of the Northern Hemisphere. These changes have reduced the diversity and quantity of TreMs. In this study we showed the relationships between stand composition, the abundance of TreMs, and the species richness of birds in a managed forest. We focused on TreMs that are important to birds: woodpecker breeding cavities, rot holes, dead branches, broken treetops, and perennial polypores. Our study was performed in a managed lowland temperate forest. In 94 plots (10 ha each) we made bird surveys and inventoried the stand composition and TreMs. Our results show that the tree stand composition of a managed forest affects the abundance of TreMs. The share of deciduous trees in the stand favors the occurrence of such TreMs as dead branches, rot holes and perennial polypores. The overall richness of bird species and the species richness of primary cavity nesters depended on the total basal area of oak, hornbeam and birch, whereas the species richness of secondary cavity nesters increased with the total basal area of birch and oak
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