Willow Bushes Research Articles

What Do Plants Leave after Summer on the Ground?—The Effect of Afforested Plants in Arid Environments

The implementation of afforestation programs in arid environments in northern China had modified the natural vegetation patterns. This increases the evaporation flux; however, the influence of these new covers on the soil water conditions is poorly understood. This work aims to describe the effect of Willow bushes (Salix psammophila C. Wang and Chang Y. Yang) and Willow trees (Salix matsudana Koidz.) on the soil water conditions after the summer. Two experimental plots located in the Hailiutu catchment (Shaanxi province, northwest China), and covered with plants of each species, were monitored during Autumn in 2010. The monitoring included the soil moisture, fine root distribution and transpiration fluxes that provided information about water availability, access and use by the plants. Meanwhile, the monitoring of stable water isotopes collected from precipitation, soil water, groundwater and xylem water linked the water paths. The presence of Willow trees and Willow bushes reduce the effect of soil evaporation after summer, increasing the soil moisture respect to bare soil conditions. Also, the presence of soil water with stable water isotope signatures close to groundwater reflect the hydraulic lift process. This is an indication of soil water redistribution carried out by both plant species.

The growth of shrubs on high Arctic tundra at Bylot Island: impact on snow physical properties and permafrost thermal regime

Abstract. With climate warming, shrubs have been observed to grow on Arctic tundra. Their presence is known to increase snow height and is expected to increase the thermal insulating effect of the snowpack. An important consequence would be the warming of the ground, which will accelerate permafrost thaw, providing an important positive feedback to warming. At Bylot Island (73° N, 80° W) in the Canadian high Arctic where bushes of willows (Salix richardsonii Hook) are growing, we have observed the snow stratigraphy and measured the vertical profiles of snow density, thermal conductivity and specific surface area (SSA) in over 20 sites of high Arctic tundra and in willow bushes 20 to 40 cm high. We find that shrubs increase snow height, but only up to their own height. In shrubs, snow density, thermal conductivity and SSA are all significantly lower than on herb tundra. In shrubs, depth hoar which has a low thermal conductivity was observed to grow up to shrub height, while on herb tundra, depth hoar only developed to 5 to 10 cm high. The thermal resistance of the snowpack was in general higher in shrubs than on herb tundra. More signs of melting were observed in shrubs, presumably because stems absorb radiation and provide hotspots that initiate melting. When melting was extensive, thermal conductivity was increased and thermal resistance was reduced, counteracting the observed effect of shrubs in the absence of melting. Simulations of the effect of shrubs on snow properties and on the ground thermal regime were made with the Crocus snow physics model and the ISBA (Interactions between Soil–Biosphere–Atmosphere) land surface scheme, driven by in situ and reanalysis meteorological data. These simulations did not take into account the summer impact of shrubs. They predict that the ground at 5 cm depth at Bylot Island during the 2014–2015 winter would be up to 13 °C warmer in the presence of shrubs. Such warming may however be mitigated by summer effects.

Wpływ odmian i klonów oraz gęstości sadzenia na zamieranie karp wierzby krzewiastej w 8-letnim cyklu uprawy

Field studies were conducted in the experimental field of Koszalin University of Technology in Kościernica, in the years 2007–2014 using 10 varieties of willow at 3 planting densities of cuttings (15 020 pcs/ha, 22 134 pcs/ha and 33 200 pcs/ha). Cuttings were planted in 2007 and one year old shoots were harvested in winter 2007/2008. In autumn of 2010 half of the plot was harvested, and in November 2011 the whole plot was harvested. Withering of basket willow bushes was highly affected by the age of cultivation, planting density cuttings and their interaction and less affected by the variety and frequency of harvesting of the shoots in the first cycle. After the fourth growing season 6.6% of bushes withered (on the average), and a large increase of the number of dead bushes on the plot occurred in the next vegetation periods (6th – 20.7%, 8th – 36.1%). The varieties were classified in terms of susceptibility to withering: very strong – Olof (22.9%), strong – Start (19.0%) and Jorr (17.9%), medium – 1047 (13.2%), 1054 (12.9%), 1047D (12.8%), Sprint (12.1%), Turbo (11.8%) and Tordis (10.5%) and small – Ekotur (6.5%). The increase in the density of cuttings planting resulted in increased withering of willow bushes. In objects harvested 1 time within the first 4-year cycle 12.2% withered on the average and in objects harvested 2 times – 15.7%. Badania polowe przeprowadzono na polu Politechniki Koszalińskiej w Kościernicy w latach 2007–2014 z 10 odmianami wierzby przy 3 gęstościach sadzenia zrzezów (15 020 szt./ha, 22 134 szt./ha i 33 200 szt./ha). Zrzezy wysadzono w 2007 roku, a jednoroczne pędy skoszono zimą 2007/2008. Jesienią 2010 roku skoszono połowę poletka, a w listopadzie 2011 roku – skoszono całe poletko. Na zamieranie karp wierzby duży wpływ miał wiek uprawy, gęstość sadzenia zrzezów i ich współdziałanie, a mniejsze – odmiany i częstotliwość zbioru pędów w I rotacji. Po czwartej wegetacji przeciętnie zamarło 6,6% karp wierzby, a duży wzrost ilości martwych karp na poletku wystąpił w następnych wegetacjach (6. – 20,7%, 8. – 36,1%). Odmiany zakwalifikowano pod względem skłonności do zamierania: bardzo silne – Olof (22,9%), silne – Start (19,0%) i Jorr (17,9%), średnie – 1047 (13,2%), 1054 (12,9%), 1047D (12,8%), Sprint (12,1%), Turbo (11,8%) i Tordis (10,5%) oraz małe – Ekotur (6,5%). Wzrost gęstości sadzenia zrzezów spowodował nasilenie zamierania karp wierzby. Na obiektach z 1-krotnym koszeniem w pierwszej 4-letniej rotacji zamarło przeciętnie 12,2% karp, a przy 2-krotnym – 15,7%.

Territory vegetation structure and habitat preferences of the Savi’s Warbler Locustella luscinioides in lake Tåkern, Sweden

Savi’s Warbler Locustella luscinioides has established as a nesting species in a few shallow reed lakes of southern Sweden during the last twenty years. Knowledge of the habitat requirements of a newly established species is important to maintain a viable population and design action plans. We examined the vegetation parameters in occupied territories of Savi’s Warblers at Lake Tåkern, the country’s stronghold for the species. We found association with the outer edge zones and fragmented areas of vegetation dominated by common reed Phragmites australis. Occupied territories differed from randomly chosen unoccupied (control) sites by having a thicker layer of basal litter, and on average more willow bushes (Salix spp.). Reed density and height did not differ between occupied territories and control sites. It is likely that the Tåkern population will continue to increase until it is limited by lack of willows or dense basal litter, the traits important for the establishment of territories. It is also likely that the species will continue to increase in Sweden as long as suitable reed habitats are left unaffected.

Occurrence of fungal diseases on willow (Salix sp.) plantations of different ageChoroby wierzby krzewiastej (Salix sp.) na roślinach w różnym wieku

Summary The occurrence of stem and leaf diseases caused by pathogenic fungi was assessed on a shrot rotation willow plantation in Krakow. Willow bushes of different age (two, four – years) were cultivated on the plantation. The research was conducted in 2006–2007. Stem cancer caused by Cryptodiaporthe salicella as a willow shoot disease occurred with the higest frequency, while the most important leaf diseases were leaf spotting (Drepanopeziza spp.) and willow rust (Melampsora spp.). The oldest bushes of willow were most severely damaged by shoot and leaf diseases. Monitoring of willow diseases is a necessary strategy for the monitoring of sanitary conditions of willows grown as bioenergetic plants.

Regeneration of willows and herbaceous vegetation on river banks after grazing by small ruminants

Willow bushes ( Salix) in a biosphere reserve cause build up of water when the river is in flood. In order to avoid flood disaster as well as for nature conservation reasons we studied whether small ruminants might suppress the willows without causing long-lasting damage both to the reeds and the vegetation of the banks. Comparing the effects of single (one time) and repeated grazing in a two-year trial, 109 sheep and 10 goats grazed up to 13 days on 8000 m 2 plots with direct access to the river. A single grazing resulted in extensive reduction of the herbaceous vegetation, but its complete regeneration within three months. This is due to a variety of strategies for survival in a dynamic bank habitat in which grazing imitates natural disturbance by changing water levels; 77.3% of the 128 species persisted under a single grazing, 10.2% were new, 12.5% were not found afterwards. Heavily reducing the biomass stimulated less competitive herbaceous species. Death of willow stems occurred only where the bark had been completely removed. The proportion that died rose from 21.7% after first grazing to 36.3% after first penning and up to 44.1% after second penning. Early grazing in the season is much more efficient (58.6%) than late (23.1%) in controlling willow growth. Insufficient damage to the bark of old multi-branched willows also reduced the proportion that died. Sustainable bark reduction of willow growth depends on damaging them severely by single grazing and then penning once early in the year, and to avoid their full regeneration by repeating this treatment every second year. Over the long-term a cyclic grazing treatment will weaken the willows and enable the herbaceous life forms to take and over reinvigorate sufficiently, suggesting it as an option for flood protection in the biosphere reserve.

Plant cover of the Szum river valley (Roztocze, South-East Poland)

The break section of the Szum river and the mouth part of its left tributary, Miedzianka (Roztocze, SE Poland) were the object of the research conducted in the years 1999-2001. The aim of the study was to establish the abiotic conditions of the diversity of vegetation and the richness of vascular flora in a small lowland river valley. A real vegetation map was drawn in the scale 1:5000. The syntaxonomic classification of plant communities and habitat trophism were established on the basis of 120 phytosociological relevés and 160 soil samples, respectively. On the area of barely 35.4 ha identified were 48 plant associations and communities representing 11 phytosociological classes, among them habitats protected in Poland (16 types) and important at the EU scale (3). There were found 378 species of 72 families, including: 21 species under strict protection, 9 under partial protection, 25 plants threatened on the regional scale, and 2 included into the Polish Red Data Book. Most of interesting species and non-forest communities occur in the parts of the valley above and below a landscape reserve 'Szum', established in 1958, covering presently 18.17 ha. The greatest floral richness was found in the peatbog-meadow complexes (<em>Phragmitetea</em>, <em>Molinio-Arrhenatheretea</em>, <em>Scheuchzerio-Caricetea</em>), in bog-alder forests and willow bushes (<em>Alnetea glutinosae</em>), and streamline ash-alder carrs (<em>Querco-Fagetea</em>, <em>Alno-Ulmion</em>), while the smallest - in the pine and poorer upland mixed fir forests (<em>Vaccinio-Piceetea</em>). Vascular flora appears to be the richest in the sections of the valley where the bottom is overgrown by non-forest communities. The results of the study indicate that it is necessary to enlarge the area of the existing nature reserve.

Distribution of ectomycorrhizal fungi in periodically inundated plant communities on the Pilica River floodplain

Studies on ectomycorrhizal symbionts in plant communities were developed in the experimental floodplain located in the middle reach of the Pilica River valley near Sulejów (central Poland). This area is a natural floodplain where habitats are permanently or periodically flooded. Its vegetation is highly diversified and includes haygrowing meadows (Molinio-Arrhenateretea), rush communities (Phragmitetea, Caricetea), willow shrubs (Salicetea) and pine monoculture. Samples of trees' and bushes' roots were collected using a metal probe, sporocarps of ectomycorrhizal fungi (ECMF) were collected together. Researches indicate that wet soil conditions and periodic flooding have a significant influence on mycorrhiza presence. The vast majority of ectomycorrhizal fungi were present in trees growing in dry habitats – willow bushes and pine monoculture (Salix species, Betula pendula and Pinus sylvestris). The species composition were determined - in total noted c.a. 40 species of ectomycorrhizal fungi and 15 morphological types. The number and diversity of ectomycorrhizal (ECM) morphotypes increased significantly from flooded to dry habitats. Despite the fact that extremely humid and dry soil conditions make a negative impact on mycorrhiza, symbiotic parthnership enable floodplain plant communities to tolerate water level fluctuations, eliminate water stress and provide plants tissues with e.g. phosphorous.

The importance of temporal dynamics of edge effect in reedbed design: a 12-year study on five bird species

Although edge effect is a key topic of conservation biology, we have no data on the temporal dynamics of it. I investigated the distribution of five passerine bird species across reedbed (Phragmites australis) edges during large-scale construction work in the Kis-Balaton marshland, Hungary. The construction provided an “experimental” approach to study the effects of large timescale changes within a shorter period, because neither the locality nor the vegetation type changed. The water level was increased in the study area, which homogenised the internal structure of reedbed by declining the scattered small willow bushes (Salix) and the grass/sedge layer. The sedge (Acrocephalus schoenobaenus) and reed warblers (Acrocephalus scirpaceus) preferred edges. The sedge warbler, however, declined after inundation, while the reed warbler did not respond. Savi’s warbler (Locustella luscinioides) sharply declined during the study with changing edge effect. The number of great reed warblers (Acrocephalus arundinaceus) increased during the study, mainly in the reedbed interior, where the stands became patchy with open water. Reed bunting (Emberiza schoeniclus) avoided interiors, and declined over the study. Therefore, there were significant changes in the distribution of reedbed birds across the edge, although the location of edges and the basic habitat, reedbed, did not change. The results highlight the need to incorporate edge effect as a dynamic process in wetland planning.

Stones in My Passway: Ellen Chesser's Country Blues and the Stone Imagery in The Time of Man

SCHOLARSHIP Stones in My Passway: Ellen Chesser's Country Blues and the Stone Imagery in The Time ofMan Dennis C. Winter Stones in my passway and my road seems dark at night, pains in my heart have taken my appetite. — Robert Johnson, blues singer. One of the most striking and persistent images in Elizabeth Madox Roberts' novel, The Time of Man, is that of stones. Ellen Chesser is constantly in touch with the stony and rocky earth of the Kentucky hill country in which she lives and travels. Furthermore, there is an attached sense of ritual invoked in many of the passages that mention these stones and rocks, whether it be in the touching of, the walking barefoot upon, or the hand-placing of stones. The path of Ellen's young life is a stony way—a path of simple hardship imbued with an overall sense of pity. Her pity and compassion for the elements and events of her life might be likened to a blues song or a personal gospel song that treats the moments of the heart from within the young girl's "poor white" perspective. Ellen's blues plaint begins with her simple skyward declaration: "Here I am! I'm Ellen Chesser! I'm here!" (89). This brief but poignant chorus is colored with a universalizing brush stroke that takes its core sense of pathos from the "faint dying phrase, 'in the time of man'." Aware that she is living her time within this overarching time of man, Ellen evinces many moments of such blues-tinged emotions that center on pity. She has pity for the corn, pity for her father, renewed pity for the farm, pity for her mother and father's futile attempts at bedroom secrecy, and finally, "she pitied them with a great pity, the pity of a child for adults" (40). We are also told by the narrator at about this time that "the perpetual sadness ofyouth had flowed upward to engulfher" (96). Ellen, at this point, is unable to gather her sense of this sadness into any concrete form of thought, and she cries out in a universally adolescent fashion: "Oh, why am I here and what is it all for anyway? I'm a-fallen through the world and there's no end to the top and no end 41 to the bottom ... there's no end to anything" (96). This is not a blues song of hopelessness, though, for ringing repeatedly within Ellen is a paradoxical, inner, salvific and comforting phrase: "It's no knowen how lovely I am. I'm a-liven. My heart beats on and on and my skin laps around me and my blood runs up and it runs down, shut in me. It's unknowen how lovely" (97). What is sad about this phrase is that it rings true for her first love. Jonas never realizes how truly lovely she is, and he squanders his chance at having a true love relationship. It might also be said that much later, Jasper, Ellen's husband, settles into a compromised role of domesticity and really may also have missed out on knowing the true depth of his wife's loveliness. But this is later in life, when the potency and heart rending impact of "first love" has passed and healed to time. At Hep Bodine's farm, the first of many tenant farm homes in which Ellen lives during the course of the novel, we see her following a creek, "jumping from white stone to white stone, feeling safe in the narrow ravine hidden among the willow bushes" (24). She is ever the country child, at home on the earth and with the earth, and often she is most at ease by herself injust such idyllic settings. Later that day she "lay on a large rocky shelf, tired from wandering. Her thin flanks sank against the white stone and her stringy legs quivered with their exhaustion" (24). Beside the cabin she "stood about the stone step, without a care," and later she returns to the cabin, walking, "moving slowly to feel the security of the path, touching a tree with her fingers, trailing her hand along the...

Nutrient dynamics of riparian ecotones: A case study from the Porijo˜gi River catchment, Estonia

The transformation of nitrogen and phosphorus was studied in various riparian ecotones of the moraine plain and moraine-hilly landscapes in the Porijo˜gi River catchment area, southern Estonia. Soil water and ground water samples were collected once per month between 1992 and 1993 from piezometers installed between plant communities located along topo-edaphic gradients from moraine uplands to stream valleys at six sites. The production rate, as well as the N and P content in plant biomass from the 1 m2 plots located near the piezometers was analyzed.Results show that various riparian ecotones had a significant influence on soil water quality. In the arable land, the mean annual concentration of total inorganic nitrogen (NH4+NO2+NO2) in piezometer water was 3–40 mg N1−1, but in the grey alder forest (Alnus incana) total inorganic nitrogen never exceeded 1 mg N1−1. The most significant reduction was in the average concentration of NO3-N content which was reduced from 25 mg 1−1 under the arable land to 0.5 mg 1−1 within the alder forest. The average total phosphorus (orthophosphate phosphorus + organic phosphorus) concentration also decreased under the alder stands, being 0.2-1.5 mg P1−1 in the arable land and less than 0.2 mg P 1−1 in the alder forest (less than 0. l mg P1−1 in loamy soils and 0.2 mg P1−1 in sandy soils). Wetland herb communities (Carex elata association and Filipendula ulmaria-Cirsium oleraceum-Aegopodium podagraria community) also had a significant influence on soil water quality. Plant biomass (sum of above- and below-ground biomass) of riparian and wetland communities accumulates up to 70 g N m−2 and up to 6 g P m−2during the growth season. Harvesting of riparian herbaceous communities may remove 20–30% of nutrient input. In the cultivated grasslands on sandy colluvial soils with a deep humus layer and sedge fens the content of NH4-N and total-P in groundwater toplayer significantly increased, rising to 3 mg and 0.5 mg−1, respectively. Also, it has been assumed that vertical penetration of deep groundwater (contaminated with nitrate and phosphate), may increase the nutrient load to surface water bodies, despite the physical presence of a wide buffer zone (e.g. sedge fen) along the river corridor. From the observations of this work, alder forests and/or willow bushes as buffer strips on and adjacent to the stream banks are recommended to control diffuse water quality.

Remex Growth and Body Mass of Mallards during Wing Molt

-We captured, banded (n = 4,129), and weighed (n = 809) Mallards (Anas platyrhynchos) during wing molt in western Poland. The condition of remex development was assessed (n = 3,421). We recaptured and remeasured 248 birds. The rate of remex growth in males (calculated by two methods) was 6.7 and 5.5 mm/day (P < 0.02). Males regained flight capability in 22-29 days, when remiges had reached 75-83% of final length. During the flightless period, males and females lost 12% of body mass. Birds whose flightless period was extended to replace only a few damaged quills continued to decline in body mass, which indicates that rate of mass loss was unrelated to costs of feather synthesis. We conclude that decrease of body mass is related to constraints on foraging time. We think this is a response to high exposure to predation during foraging. Reduction of flightlessness seems to be realized by a high growth rate of remiges, which was almost constant and independent of body mass. Received 24 August 1988, accepted 25 September 1989. LIKE other waterfowl, Mallards shed all their primaries and secondaries simultaneously, and are flightless during the period of wing molt. Flightless birds are more susceptible to predation, and movements are constrained. This situation influences habitat selection, antipredator behavior, foraging, and energy budget. Body mass decreases and body composition changes during flightlessness. Several hypotheses attempt to account for the changes in body mass. Hanson (1962) concluded that remex molt is a period of great nutritional stress for Canada Geese, and birds must catabolize body tissues to build feathers. Ankney (1979) argued that flightless geese can meet their nutrient requirements from the diet, and that maintenance of a superfluous reserve would be a waste of energy. Decreased body mass during molt may be adaptive, because it enabled birds to fly before completing growth of remiges, and this reduced the flightless period (Douthwaite 1976, Dean and Skead 1979, Owen and Ogilvie 1979, Bailey 1985, Austin and Fredrickson 1987, Sjoberg 1988). Young and Boag (1982) suggested that ducks may lose feeding opportunities as a result of secretive behavior. Douthwaite (1976) suggested that reserves accumulated before the molt make birds less vulnerable to food shortages where they would be exposed to predators. These hypotheses are not mutually exclusive, and Pehrsson (1987) suggested that limitation of foraging and use of body reserves minimalize exposure to predation and simultaneously shorten flightlessness. STUDY AREA AND METHODS This study was conducted in the floodplain of the River Warta at its confluence with the Odra River, western Poland (Majewski 1986). Flightless ducks concentrate in willow bushes (Salix spp.) surrounded by shallow water. The number of male Mallards that molt here reaches 25,000, many times greater than the number of local breeders. In 1981-1982 flightless Mallards were surrounded and driven into a net enclosure (Majewski 1981). Birds were banded (3,788 males and 341 females), weighed to the nearest 20 g (640 males and 169 females), and the ninth primary was measured to the nearest 1.0 mm (3,143 males and 278 females). The birds were then released. We recaptured 337 males and 13 females, typically after 3-9 days. Each was remeasured. Because most females were trapped late in the season, there were relatively few recaptures. We calculated the rate of remex growth from differences between lengths of the remiges divided by number of days between capture and recapture of each individual (n = 237). Birds with broken or pulled remiges were excluded, but some damage to remiges might have been overlooked. When caught for the first time, some birds shed their remiges, but regrowth was not yet visible. Recapture of these birds (n = 12) provided remex growth rates from the beginning of feather replacement. The remex length required to resume flight was established from the longest primaries among captured birds. We assumed that birds capable of flying could not be captured. We measured final length of the ninth primary in 18 males and 50 females caught or shot in other seasons. We estimated duration of flightlessness from the growth rate of remiges. Changes in body mass during molt were calculated 255 The Auk 107: 255-259. April 1990 This content downloaded from 207.46.13.101 on Sat, 08 Oct 2016 05:49:11 UTC All use subject to http://about.jstor.org/terms 256 PANEK AND MAJEWSKI [Auk, Vol. 107

The influence of nesting habitat on reproductive success of the lesser snow goose

The quality of nesting habitat and the influence of vegetation height on reproductive success of the lesser snow goose (Chen caerulescens caerulescens) were examined. In 1984, geese nesting in tall willow bushes (Salix ssp.) were more successful than individuals nesting in shorter willows, or in areas with no willows at all. In particular, individuals nesting in tall willows lost fewer eggs to depredation or abandonment, resulting in a greater number of goslings leaving the nest after hatch. The effect of willow height on reproductive success was independent of female age and relative nest initiation date, both of which are known to affect reproductive success. The degree of the habitat effect was not as great in 1986, but the geese nesting in willow bushes did tend to have greater reproductive success. Since spring environmental conditions influence both the availability and quality of nest sites, the potential importance of the effect of nesting habitat on reproductive success probably varies among years.