Alder Forest Research Articles

Impatiens noli‐tangere L.

<i>Impatiens noli‐tangere</i> L.

Malacocenoses of the nature reserve Buki nad Jeziorem Lutomskim

A 15-month study in a beech forest and alder forest in a nature reserve Buki nad Jeziorem Lutomskim revealed the presence of 36 land gastropod species of 14 families. Euryoecious species and forest species of European distribution dominated. The mean density of gastropods in the beech forest was 36 indiv./m 2 , in the alder forest 27 indiv./m 2 . The density in the beech and alder forest was the highest in winter, the lowest in summer. A highly significant correlation was found between the density and the number of spe- cies. In the beech forest malacocenosis, the superdominant was Discus rotundatus (O. F. Muller), the eudominant being Cochlodina laminata (Montagu). In the alder forest, no superdominant could be distin- guished, the eudominants being Discus rotundatus (O. F. Muller) and Cochlodina laminata (Montagu). Domi- nant species, as well as the number of species, species diversity, equitability and frequency varied between months. In the beech forest Discus rotundatus (O. F. Muller) - an accessory species - showed the highest fre- quency; in the alder forest all species were accidental. Juvenile individuals were more numerous than adults in spring samples from the beech forest and in autumn samples from the alder forest.

Energy efficiency of large cardamom grown under Himalayan alder and natural forest

Energy efficiency of agroforestry systems of large cardamom grown under N2-fixing Himalayan alder (alder-cardamom) and natural forest (forest-cardamom) was studied in the Sikkim Himalaya. Large cardamom (Amomum subulatum), the most important perennial cash crop of the region, is widely cultivated with Himalayan alder (Alnus nepalensis) as shade tree. Energy fixation, storage, net allocation in agronomic yield, and heat release and exit from the system were respectively 1.57, 1.44, 2.24 and 2.22 times higher in the alder-cardamom compared to the forest-cardamom system. Energy conversion efficiency and net ecosystem energy increment were also higher in the alder-cardamom than the forest-cardamom system. Energy fixation efficiency and energy conversion efficiency of large cardamom increased under the influence of Himalayan alder. Energy efficiency in N2-fixation of Himalayan alder was also high (67.5 g N2 fixed 104 kJ-1 energy). Quantum and flux of energy increased in the alder-cardamom compared to the forest-cardamom system that optimized the production potential of the cash crop under the influence of the Himalayan alder. Climatic sympatry of the large cardamom and Himalayan alder, and their synergetic energy efficiency makes this association ecologically and economically viable for the mountain regions.

Budgets of nitrogen fluxes in riparian grey alder forests.

Transects were established on two hillslopes and two study nitrogen budgets in two complex riparian buffer zones receiving different nitrogen loading. In the heavily loaded site the average total-N content decreased from 23 mg l -1 to 3.1 mg l -1 in a 40-years-old riparian grey alder forest (80 % removal). At the site with low loading the average removal of total-N was 48 %. In both transects the budget of N fluxes was established. In the older forest it was estimated as high as 321.1 kg ha -1 yr -1 , being 285.3 kg ha -1 yr -1 in the younger one. Considering all inputs and outputs, the N removal efficiency in grey alder stands slows down with increase of age. In the same time, immobilization in soil is increasing. This suggests that grey alder buffer communities should be managed by regeneration cutting and tending to keep their nitrogen removal rate high.

Field measurements of root respiration and total soil respiration in an alder forest

Summary • Variation in root respiration and total soil respiration measured in the field in an alder (Alnus glutinosa) forest is reported here, complementing previous studies of below‐ground carbon relations. • A novel technique, involving minimum disturbance to the roots, was used to measure tree fine‐root respiration, while soil respiration was measured in an open system using infrared gas analysis. Calculations by process models of both rhizomicrobial, and bulk soil, respiration were compared with measurements of total soil respiration. • The rhizomicrobial respiration rate was strongly temperature dependent, with the variation determined by fine root structural parameters. The data were used to calibrate a soil respiration model comprising mineralization and rhizomicrobial respiration submodels. The calculated annual rhizomicrobial respiration (1234 g m−2) matched the carbon balance of the alder trees calculated in earlier studies; however, the calculated total annual soil CO2 efflux (1754 g m−2) was very high compared with other European forest sites. • The modelled total soil respiration fitted well to measured values; a changing groundwater table and modified carbon partitioning of the alder trees might account for deviations during early summer.

El género Hypseocharis (Oxalidaceae) en la Argentina

Slanis A. C. & Grau A. 2001. The genus Hypseocharis (Oxalidaceae) in Argentina. Darwiniana 39(3-4): 343-352. A taxonomic revision of the genus Hypseocharis in Argentina is presented. Two species are considered: Hypseocharis tridentata and H. pimpinellifolia. H. corydalifolia is considered a synonym of H. pimpinellifolia. Flowers and fruits of H. tridentata are described for the first time. This species has a whorl of 5 alternate stamens and a schizocarpic fruit breaking away as five dehiscent mericarps with 1- few seeds per locule. These characters differ substantially from the original description of the genus, which indicated 15 stamens in two whorls and a capsule with loculicidal dehiscence containing many seeds. H. pimpinellifolia has a wide distribution in cloud grasslands, high Andean grasslands and Puna environments between 2000 and 4200 m in Jujuy, Salta, Tucuman, Catamarca and La Rioja provinces. H. tridentata is a relatively rare species, restricted to a narrow belt of cloud grasslands above the Andean alder forest between 2500 and 3200 m in Jujuy, Salta and Tucuman provinces.

Characteristics and energetic strategies of the rhizosphere in ecosystems of the Bornhöved Lake district

This paper reviews investigations on interactions between soil microbiota, and plants during the interdisciplinary program ‘Ecosystem research in the Bornhöved Lake district’; it deals with processes associated with the rhizosphere at four agricultural, and forest ecosystems. Emphasis was placed on a black alder forest representing the interface between terrestrial and aquatic ecosystems. In the alder forest, more than 96% of the alder roots were colonised by ectomycorrhizal fungi. The diversity and vitality of these mycorrhizal rootlets exhibited local differences being generally lower at a dystric-dry site compared to an eutric-wet site close to the lake. Bacterial populations typical of well-aerated arable soils and rhizosphere soils were detected in samples taken from the soil at the eutric-wet site although unfavourable anoxic conditions were assumed to occur near to the lake. The composition of the bacterial populations seems to be profoundly influenced by the plant. Furthermore, the Alnus– Frankia-symbiosis showed a high spatial variability and was also more extensively established at the lake shore indicating both higher nitrogen requirement of the trees and higher energy supply for N 2-fixing actinomycetes by the tree. The high energy supply by the trees at the eutric-wet site could be confirmed by the soil carbon availability index. The role of plants on in situ soil respiration was estimated for agricultural and forest sites. The aggregated and modelled data for arable soil indicated that the respiration of roots and rhizosphere organisms contributed up to 40% of the total soil respiration during summer. An even higher contribution to soil respiration may have been derived from rhizomicrobial respiration in the alder forest. In conclusion, the amount of carbon delivered below ground seemed to be adjusted dependent on ecosystem type and environmental conditions. In particular, alder trees seemed to have established a beneficial environment for the microbiota in the rhizosphere.

Hierarchical control on nitrous oxide emission in forest ecosystems

While much is known about process level control on N2O production by nitrification and denitrification, knowledge of the environmental controls responsible for site variation in annual N2O fluxes on ecosystem level is low. Our goal was to improve existing concepts of controls on N2O fluxes. We measured N2O emission weekly or biweekly during 1 year in 11 temperate forest ecosystems using closed chambers. We identified three types of forest with different temporal emission patterns: forest with seasonal, event‐based and background emission patterns. Comparison of annual data sets from literature showed that most temperate forests had low N2O emissions throughout the year (background emission pattern) with mean annual fluxes of 0.39 ±0.27 kg N ha−1 yr−1 (n = 21). Event‐based emission patterns were observed during frost/thaw periods and after rewetting. Highest fluxes up to 72 kg N ha−1 were emitted from a drained alder forest with organic soil in 46 weeks, followed by well drained tropical and temperate forests with seasonal emission patterns and fluxes between 2 − 6 (n = 3) and 1 − 5 kg N ha−1 yr−1 (n = 4), respectively. Seasonal emission patterns were explained by combined effect of high annual precipitations; broad leave trees; amount and structure of organic upper horizon; high mineral bulk densities; and plant community. These state variables reduce gas diffusivity so that oxygen demand by microorganism and roots exceeded oxygen supply during wet and warm periods (&gt;10° C). The resultant upper mean level was about 100 μg N2O−N m−2 h−1 in both temperate and tropical forests. Annual N2O losses of the seasonal emission type were controlled by both duration and upper mean level of the periods with high emissions. We conclude that “short‐term controls” of climate determine the duration of high emissions, whereas “long‐term controls” by state variables determine the difference between background and seasonal emission types.

Ecotechnological Measures to Control Nutrient Losses from Catchments

Ecotechnological measures allow to use different natural and seminatural ecosystems to control nutrient losses from intensively used watersheds. The most effective means are buffer strips, buffer zones and constructed wetlands. In southern Estonia a 31 m wide buffer zone of wet meadow and grey alder forest removed 50% nitrogen and 78% phosphorus, while in a 51 m buffer zone, also containing a grassland strip in addition to wet meadow and alder forest, 87 % N and 84 % P was retained. The outflow of total – N was 4.9% and outflow of total – P was 4.8% lower in well-buffered watershed in comparison to similar watershed with lower buffering ability. Three constructed wetlands in southern Estonia were studied. The removal efficiency was 76 – 84% for BOD5, 39 – 70% for total-N, 73 – 83% for total-P. All results show that compared to other seasons the winter performance was not reduced.

Leaf water relations of black alder [ Alnus glutinosa (L.) Gaertn.] growing at neighbouring sites with different water regimes

The tree species black alder [Alnus glutinosa (L.) Gaertn.] typically inhabits wet sites in central Europe but is also successful on well drained soils. To test the physiological adjustment of the species in situ, conductances, transpiration rates and water potentials (Scholander pressure chamber) of black alder leaves were investigated at two neighbouring sites with different water regimes: alder trees at an occasionally water logged alder forest and alder shrubs in a nearby, much drier hedgerow. Additional experiments with alder cuttings in nutrient culture showed that leaf conductances and gas exchange were both strongly influenced by the substrate water potential. In situ however, there was little spatial variability within the different parts of a crown and we found that physiological regulation at leaf level was hardly influenced by different site water regimes or different tree sizes. Diurnal courses of leaf water relations as well as their regulation at the leaf level (e.g. the hyperbolic relationship between conductances and ΔW) were strikingly similar at both sites. Leaf water potential in black alder was shown to be a consequence of immediate transpiration rates, which were high in comparison to other tree species (up to 4 mmol H2O m–2 s–1), rather than the water potentials being a factor that influenced conductance and, therefore, transpiration. The always high leaf conductances and consequent high transpiration rates are interpreted as a strategy to maximise productivity through low stomatal limitation at sites where water supply is usually not limited. However, at the same time this behaviour restricts black alder to sites where at least the deep-going roots can exploit water.

Ecotechnological measures to control nutrient losses from catchments

Ecotechnological measures allow to use different natural and seminatural ecosystems to control nutrient losses from intensively used watersheds. The most effective means are buffer strips, buffer zones and constructed wetlands. In southern Estonia a 31 m wide buffer zone of wet meadow and grey alder forest removed 50% nitrogen and 78% phosphorus, while in a 51 m buffer zone, also containing a grassland strip in addition to wet meadow and alder forest, 87 % N and 84 % P was retained. The outflow of total – N was 4.9% and outflow of total – P was 4.8% lower in well-buffered watershed in comparison to similar watershed with lower buffering ability. Three constructed wetlands in southern Estonia were studied. The removal efficiency was 76 – 84% for BOD 5 , 39 – 70% for total-N, 73 – 83% for total-P. All results show that compared to other seasons the winter performance was not reduced.

Nitrogen and phosphorus requirement of the microbiota in soils of the Bornhöved Lake district

Estimating in situ N and P status of the soil microbiota is complicated because microbiological features reflect potentials rather than field conditions. Complementary microbiological assays were, therefore, combined to evaluate the N and P requirement of the microbiota in seven agricultural, grassland and forest topsoils of the Bornhoved Lake district as follows: (i) the sensitivity of the substrate-induced respiration (SIR) to supplemental addition of N and P was monitored during microbial growth and (ii) soil protease and phosphatase activities were analysed and related to soil mass and microbial biomass content. Nitrogen addition increased the maximal SIR rate in all except one soil indicating that the growth of organisms is restricted by this element when easily degradable C source is present. Supplemental N (and in some cases also P) retarded the respiratory response within the first 24 h which suggests microbial sensitivity and/or greater anabolic efficiency. With additional N the maximal SIR rate was most strongly enhanced in topsoils of the beech forest and the dystric alder forest. Thus, the microbial growth in these soils that were below litter horizons seems to be mostly restricted by N. Supplemental P positively affected respiratory response of soils under monoculture, wet grassland and dystric alder forest. In the dystric alder forest soil, high rates of alkaline and unbuffered phosphatase activity were observed when activity was related to either soil mass or microbial biomass content. The data of proteolytic and phospholytic enzymes are discussed with reference to nutrient deficiency and microbial strategy for N and P adsorption.

Ratios between estimates of microbial biomass content and microbial activity in soils

The content levels and activities of the microbiota were estimated in topsoils and in one soil profile at agricultural and forest sites of the Bornhoved Lake district in northern Germany. Discrepancies between data achieved by fumigation-extraction (FE) and substrate-induced respiration (SIR), both used for the quantification of microbial biomass, were attributed to the composition of the microbial populations in the soils. In the topsoils, the active, glucose-responsive (SIR) versus the total, chloroform-sensitive microbial (FE) biomass decreased in the order; field maize monoculture (field-MM)>field crop rotation (field-CR) and dry grassland>beech forest. This ratio decreased within the soil profile of the beech forest from the litter horizon down to the topsoil. Differences between microbial biomass and activities suggested varying biomass-specific transformation intensities in the soils. The metabolic quotient (qCO2), defined as the respiration rate per unit of biomass, indicates the efficiency in acquiring organic C and the intensity of C mineralization, while biomass-specific arginine-ammonification (arginine-ammonification rate related to microbial biomass content) seems to be dependent on N availability. The qCO2, calculated on the basis of the total microbial biomass, decreased for the topsoils in the same order as did the ratio between the active, glucose-responsive microbial biomass to the total, chloroform-sensitive microbial biomass, in contrast to qCO2 values based on the glucose-responsive microbial biomass, which did not. There was no difference between the levels of biomass-specific arginine-ammonification in topsoils of the fertilized field-CR, fertilized field-MM, fertilized dry grassland and eutric alder forest, but levels were lower in the beech forest, dystric alder forest, and unfertilized wet grassland topsoils. Ratios between values of different microbiological features are suggested to be more useful than microbiological features related to soil weight when evaluating microbial populations and microbially mediated processes in soils.

Denitrification enzyme activity of Douglas-fir and Red Alder Forest soils of the Pacific Northwest

Nitrogen-fixing red alder ( Alnus rubra Bong.) increases soil organic matter and N content of forest soils. This study compared denitrification enzyme activity (DEA) to related N-cycling and microbial indicators in adjacent stands of alder and Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) in two Pacific Northwest U.S.A. research forests over 16 months. Laboratory denitrification rates were measured in non-amended soils and soils amended with combinations of water, NO 3 −, and glucose. The NO 3 −-and glucose-amended soils provided estimates of DEA. DEA in alder soils was greater than or equal to that in corresponding Douglas-fir soils. Denitrification in alder soils was occasionally limited by energy source (glucose) but not by NO 3 −, whereas in Douglas-fir soils, it was frequently limited by both NO 3 − and glucose. For a given soil, DEA was generally not well related to respiration potential, anaerobic mineralizable N, or exchangeable ammonium over time, but it was well related to nitrification potential across different soils and over time within two soils.

Nitrous oxide emissions and denitrificationN-losses from forest soils in the Bornhöved Lake region (Northern Germany).

In situ denitrification N-losses and nitrous oxide emissions were measured over 12 months from a beech and a drained black alder forest of Northern Germany. Annual N-losses from the alder forest soil were approximately 15 times greater than from the beech forest soil (denitrification: 7.0 vs 0.4 kg N ha −1 y −1; nitrous oxide: 4.9 vs 0.4 kg N ha −1 y −1, respectively). These results were attributed to the soil moisture content, and contents of nitrate and water-soluble organic C compounds in the alder forest soil being significantly greater than in the beech forest soil. The ratio denitrification N-losses-to-nitrous oxide emissions revealed high denitrifier activity in the alder forest soil while in the beech forest soil nitrification predominated. The time course of nitrous oxide emissions and denitrification N-losses on both sites were similar and underwent seasonal changes. The best predictor for the emissions of the alder forest soil was the soil temperature ( r 2=0.63 and 0.44 for nitrous oxide and denitrification, respectively).

Food Plants, Species Composition and Variability of the Moth Community in Undisturbed Forest

The present study is based on a 14-yr time series of light trap data of moths (Lepidoptera) species in an undisturbed alder swamp forest in Central Europe. Vegetation change was followed on five pennanent plots. The biomass of all plant species in the portion of the forest surrounding the light trap was determined. As the feeding specificity of all the moth species was known, we were not only able to categorize moth species according to their potential feeding specificity, but were also able to estimate total food supply and its diversity in the studied ecosystem. In monophagous species, moth population size, characterized by mean annual catch, was positively correlated with food supply, whereas in oligo- and polyphagous species the correlation was close to zero. Although the ability of plant species to support a monophagous moth is positively dependent on its biomass, there are some relatively rare plant species supporting monophagous moths, and some common species not supporting monophagous moths. Directional changes were found both in plant and moth species; directional changes in moth species are more pronounced than changes in plant cover. There is no evidence suggesting that directional changes in moth population sizes are caused by the changes in food supply. Pronounced directional changes were found mainly in species not confined to the closed alder forest and are related to changes in wider areas, in some cases with known changes in species distribution. Non-directional year-to-year variability, described by Lloyd's index, is best explained by the potential population growth rate of a moth species estimated on the basis of species fecundity. Correlation of Lloyd's index with number of food plant species is significantly positive, but low (r = 0.25); no significant differences were found between categories of feeding specificity. This shows that the dependence of population variability on species feeding specificity, both potential and expressed as number of food plants in the ecosystem, is weak.

Morphological and anatomical characterisation of black alder Alnus glutinosa (L.) Gaertn. ectomycorrhizas

Ectomycorrhizal types of black alder [Alnus glutinosa (L.) Gaertn.] collected over a 3-year period within an alder forest were characterised by morphological and anatomical features. Of the total of 16 types, 14 are described for the first time in this paper. Eight identified types belong to the genera Russula, Lactarius, Naucoria, and Cortinarius, while eight further types remained unidentified. In some cases, similarities of mantle features indicate relationships to identified mycorrhizas. Mycorrhizas of Naucoria escharoides and N. subconspersa were not distinguished. Two unidentified mycorrhizal types exhibited hyphal mantle structures very similar to these Naucoria species. Within the genus Cortinarius, mycorrhizas of C. cf. helvelloides were easily distinguished from all other Cortinarius-like mycorrhizas described on Alnus, which in general showed little anatomical variation. Two further unidentified mycorrhizas, "Alnirhiza lilacina" and "A. violacea", probably also belong to Cortinarius. The ectomycorrhiza of Russula pumila was the only identified type within the genus Russula, but the unidentified type "Alnirhiza cremicolor" also likely belongs to this genus. Three Lactarius species were present in the experimental plot. Two species (L. obscuratus and L. omphaliformis) had indistinguishable mycorrhizal types, but were easily differentiated from the mycorrhizas of L. lilacinus, which caused intracellular penetration of Hartig net hyphae into epidermal and cortical cells. All other mycorrhizal types of black alder exhibited a paraepidermal Hartig net without penetration of root cells. Two unidentified mycorrhizal types "Alnirhiza atroverrucosa" and "A. cystidiobrunnea", already described from North American Alnus rubra as unnamed morphotypes, showed no similarity to identified mycorrhizas. All 16 mycorrhizal types appeared to be specific or at least typical for alders, since they have not yet been reported from other tree species.

Field measurements of carbon leaching from leaves in beech and alder forests of northern Germany

Summary Carbon compounds were measured in solutes from crown drip and stem flow collected by rain gauges in a beech and an alder stand in northern Germany. The amount of leachate was calculated by using the concept of a canopy deposition model. Under this aspect leaching rate is the difference between canopy and bulk deposition. The calculations comprise direct leaching from leaves as well as carbon loss to honey-suckling insects and carbon loss used to compensate loss of inorganic substances. Leaching of organic carbon depends mainly on the amount of rainfall, the activity of phytophages and on the water repellance of the leaf cuticles. The annual loss of organic carbon by leaching was about 300 kg · ha −1 per year in the alder forest, that was 1,4% of the annual gross carbon production. The loss in the beech forest was lower with about 60 kg C · ha −1 year −1 , corresponding to 0,8%.

Key variables controlling the vegetation of a cool‐temperate mire in northern Japan

Abstract. In the cool‐temperate Bibi Mire, Hokkaido, Japan, valley fens and flood‐plain fens have quite different vegetation. The main variables controlling the vegetation were all hydrological: mean water level, water level fluctuation and surface water flow. Chemical factors such as electrical conductivity, dissolved oxygen and related peat decomposition were less important. The pH was about neutral and has little effect. The flood‐plain fen developed under fluctuating water table conditions. The dominant species are Calamagrostis langsdotffii and Carex pseudocuraica. When temporal inundation occurs in the rainy or typhoon seasons, the submergence stimulates bud germination of the stoloniferous C. pseudocuraica, which can rapidly elongate its stolons upward. Some large floating peat mats occurred in the flood‐plain fen zone. On these mats some Alnus japonica saplings establish and patches of alder forest can arise. Here the water level was higher than in the peripheral alder forest zone.The valley fen is dominated by Carex lasiocarpa var. occultans and/or C. limosa. It is formed under stable water table conditions in the inundated parts of the mire ‐where the non‐inundated wet areas are dominated by alder trees. In the area where the surface water is flowing, these two fen sedges grow in deeper water since the high oxygen content is considered to compensate the flooding stress.

Mechanisms of Negative Impacts of Three Forest Treatments on Nutrient Availability

AbstractMany forest management treatments are directly aimed at maintaining or enhancing forest productivity. There may also be secondary effects that detract from this goal. We discuss three case studies in Washington state in which several mechanisms may have led to adverse secondary impacts. In the first study, pulp and paper (PII) sludges were mixed into soil and growth of Douglas‐fir [Pseudotsuga menziesii (Mirb.) Franco], noble fir (Abies procera Rehder) and western white pine (Pinus monticola Douglas ex D. Don) was monitored. There was a significant negative correlation of height and diameter growth and C/N ratio for Douglas‐fir and western white pine (0.05 level). In a second study, effects of 50 yr of red alder (Alnus rubra Bong.) and Douglas‐fir growth on soil chemistry and stand productivity were compared. When the 50‐yr‐old stands were cut and red alder was established by planting into the soil of the former Douglas‐fir and red alder forests, lowered available P in the soil of the previous red alder stand was observed. In a third study, high rates of low C/N ratio organic matter (300 Mg ha−1) were added in municipal biosolids (N amount about 8000 kg ha−1) to Douglas‐fir and grand fir [Abies grandis (Dougl.) Forbes] plantations. Excess organic N in the biosolids apparently mineralized, nitrified, and contributed to soil acidification and accelerated cation leaching. Severe Mg deficiency (0.25 g kg−1 in biosolids‐treated vs. 0.93 g kg−1 in untreated area) might be the cause of observed foliar chlorosis and poor growth rates.