Current distribution of older and deciduous forests as legacies from historical use patterns in a Swedish boreal landscape (1725–2007)

We combine historical maps and satellite derived data to reconstruct the development of a Swedish boreal landscape over the past 300 years. The aim is to understand legacies from past use patterns in present-day forest composition and consequences for conservation objectives from a landscape perspective. We analyze landscape development in cross-tabulation matrixes, building change trajectories. These trajectories are tested in linear models to explain the distribution of present-day landscape composition of coniferous, mixed, and deciduous forests >110 years. Of 49 tested change trajectories, 11 showed a significant association. Associations for mixed and coniferous forests were similar and linked to characteristics such as forest continuity, which characterized the studied landscape. Deciduous older forests did not show any association to forest continuity but were more likely to occur on areas that specifically shifted from forests with grazing in the 1720s to open impediment (likely indicating low tree coverage) in the 1850s. There were large shifts and spatial redistribution in ownerships over time. Use patterns and legacies varied between small- and large-scale ownership categories as well as within small-scale categories. The legacies found in the study indicate a complex origin of heterogeneous landscape elements such as older deciduous forests. Additionally, the origin of the legacies indicates a potential need to diversify conservation management based on the influence of past use patterns. Despite large inconsistencies in historical and contemporary data we argue that this type of analysis could be used to further understand the distribution of landscape elements important for conservation objectives.     

Assessment of progesterone profiles and postpartum onset of luteal activity in spring calving Hereford beef suckler cattle

Background

Reproduction is the single greatest factor limiting beef cattle production. Previous research on beef suckler luteal activity has largely focused on the mechanisms, and duration, of postpartum anoestrus. However, the temporal pattern of luteal activity after resumption of post-partum ovarian activity, and the impact of pattern type on days open (DO) in purebred beef suckler cows, are unknown.

Methods

Progesterone concentration was measured in milk samples taken thrice weekly from 120 lactations, in 87 animals, on 3 farms, over two years. Onset of luteal activity (OLA) was defined as the first day milk progesterone concentration exceeded 3 ng/ml for two successive measurements, or exceeded 5 ng/ml once. It was defined as delayed if it occurred more than 61 days postpartum. A short initial luteal phase consisted of progesterone concentrations which exceeded 3 ng/ml for fewer than 4 sequential measurements. Temporal progesterone patterns were classified as: 1) Normal cyclicity; 2) Cessation of luteal activity; 3) Prolonged luteal activity; 4) Erratic phase: failure to conform to 1, 2 or 3. Data concerning parity, previous calving interval, breeding values, calf birth and 200-d weight were obtained from the Norwegian Beef Cattle Recording System database.

Results

The mean (SD) OLA was 41 d (20). Parity and calf birth weight were inversely correlated with OLA. Delayed OLA occurred in 14.4% of lactations. A short first luteal phase occurred in 61.5% of lactations, but this was unrelated to irregular luteal phase occurrence, pregnancy or DO. Irregular luteal phases occurred in 22% of lactations. The irregularities were: prolonged luteal phase (11%); cessation of luteal activity (5%); erratic luteal activity (6%). Early OLA was associated with prolonged luteal phases. DO was positively correlated with irregular luteal phases and negatively correlated with calf 200-d weight.

Conclusions

This study demonstrates that irregular luteal phases negatively affect reproductive performance in purebred beef suckler cattle. A moderate incidence of irregular luteal phases was seen in the study population. Whilst a positive relationship was seen between OLA and DO, unfavourable associations between early OLA and incidence of irregular luteal phases should be considered when developing breeding programmes.     

Manipulating behaviour with substrate‐borne vibrations – potential for insect pest control

This review presents an overview of the potential use of substrate‐borne vibrations for the purpose of achieving insect pest control in the context of integrated pest management. Although the importance of mechanical vibrations in the life of insects has been fairly well established, the effect of substrate‐borne vibrations has historically been understudied, in contrast to sound sensu stricto. Consequently, the idea of using substrate‐borne vibrations for pest control is still in its infancy. This review therefore focuses on the theoretical background, using it to highlight potential applications in a field environment, and lists the few preliminary studies that have been or are being performed. Conceptual similarities to the use of sound, as well as limitations inherent in this approach, are also noted. © 2014 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Nitrogen metabolism in dairy cows fed restricted amounts of grass–clover silage supplemented with seeds from narrow-leafed lupin or pea

Twelve dairy cows in mid to late lactation were fed iso-nitrogenous diets (161 g CP/kg DM, forage:concentrate ratio 65:35) where rolled barley and coarsely ground seeds from either narrow-leafed lupin or field pea supplemented grass–clover silage. Feed allowance was individually restricted and fixed (18.8 ± 0.6 kg dry matter/day) throughout the experiment to avoid refusals. The experiment was of 2 × 2 change-over design and utilized a previous change-over experiment with 3 periods as covariate. Nitrogen balance was assessed by quantitative urine sampling and fecal spot sampling in eight cows whereas rumen metabolism was studied in four cannulated cows. Production of energy corrected milk was 24.3 kg/day with the lupin diet and 23.2 kg/day with the pea diet (P < 0.05). Daily milk fat yield was also higher (P < 0.05) with the lupin diet. Proportion of feed N excreted in milk did not differ between diets. Milk urea concentration, as well as the amounts of total urinary N and urinary urea were higher (P < 0.05) for the lupin diet, while urinary N proportion of feed N only tended (P = 0.08) to be higher with the lupin diet. N balance was lower with the lupin diet. Digestibilities of organic matter, neutral detergent fiber and crude protein did not differ between diets and neither did ruminal pools of these constituents. In addition, there were no differences between the diets with respect to the ruminal concentrations of NH₃-N and total volatile fatty acids, and only minor differences in ruminal pH and ruminal concentrations of iso-acids and α-amino-N. It is concluded that the higher fat content in lupins compared to peas is an advantage in typical Scandinavian home-grown rations and probably explains the higher milk yield in this experiment. Differences in protein utilization between lupins and peas are of small magnitude when fed ground without thermal processing. In practical feeding, ad libitum forage allowance may create response differences between lupin seeds and peas not observed in this experiment.     

Hunting reduces recruitment of primate-dispersed trees in Amazonian Peru

Hunting with firearms decimates primates of large and medium body size (>2 kg) that disperse the seeds of large-seeded trees. In continuous, un-fragmented forests of southeastern Peru regularly hunted with firearms for 30-40 years, large primates are extirpated and medium-sized (medium) primates are reduced 61% compared with protected forests. At hunted sites seedlings and small juveniles (<1 m height) of trees dispersed by primates heavier than 2 kg are reduced 46%, a loss of one species m⁻², and abiotically-dispersed plants are 284% more common, adding eight individuals m⁻², compared with protected forests. Here we provide evidence consistent with the long-held prediction that commercial hunting changes plant communities. We show that the composition of seedling and small juvenile tree communities that ultimately regenerate future forests differs markedly in forests hunted with firearms compared with protected forests. This opens the possibility of shifts in tree species composition, even in hunted forests that are not logged or fragmented, towards forests dominated by trees dispersed by wind or non-game animals.     

Modelling Acidification Effects on Coniferous Forest Soils

Two submodels for simulating the leaching of forest soils are described. SOILORG is used for O, E, and top B layers where Al(OH)₃ is absent and organic matter is the major base cation storage. SOILMIN cares for the rest of the profile where Al(OH)₃ control of Al is assumed and goethite provides most of the sulphate storage, clay mineral surfaces providing base cation storage. Results are presented from a test run for the period 1911 to 2030, based on data from a 260 cm deep soil profile in the SW of Sweden investigated 1990 and on a likely deposition scenario. Considering that the deposition of base cations exceeded the removal by stemwood in 1911 when the simulation started, the biologic acidification of the soil profile had reached a steady state before 1911 so that no additional acidification took place before 1930 and very little before 1950. After 1950 it was strongly enhanced by the increased acid deposition. In the mineral soil a considerable resistance against acidification is offered both by base cation exchange and sulphate adsorption, creating an acidification front which moved slowly down the B-horizon then accelerated, reaching the bottom of the profile in 1990. A deposition reduction by 2/3 during 1990–2010 will cause a partial recovery of pH, particularly in the deeper parts of the profile.     

Management of sea cucumber stocks: patterns of vulnerability and recovery of sea cucumber stocks impacted by fishing

Identifying rates of change in the abundance of sea cucumbers under differing management regimes is fundamental to estimating commercial yields, identifying ecological interactions and facilitating management. Here, we review the status of sea cucumber stocks from a range of Pacific Island countries (Samoa, Tonga, Palau, Fiji and Papua New Guinea), some of which have had a moratorium on exports for up to a decade. We use a time‐series approach to look at variation in sea cucumber presence, coverage and density from survey and re‐survey data. Results give an appreciation of variation between ‘high’ status (less impacted) and depleted stocks. Survey data show marked declines in coverage and abundance as a result of artisanal fishing activity, and although species groups were not lost at a country level, local extirpation and range restriction was noted. Resilience and ‘recovery’ following cessation of fishing varied greatly, both among locations and among the species targeted. Worryingly, even after extended periods of moratorium, the density of some species was markedly low. In many cases, the densities were too low for commercial fishing, and may be at a level where the effective population size is constrained due to ‘Allee’ affects. From these results, we suggest that management regimes presently employed are generally not well aligned with the level of response to fishing mortality that can be expected from sea cucumber stocks. New adaptive, precautionary approaches to management are suggested, which would allow more timely interventions to be made, while refined information on stock dynamics is sought.     

Production of high yielding red raspberry long canes in a Northern climate

Techniques for the production of raspberry long canes with high yield potential were studied on a research station and in two commercial nurseries in South Norway. Potted ‘Glen Ample’ plants were grown in the open and in polyethylene greenhouses during two seasons in order to optimize cultural practices. Dates of propagation and transfer to the production sites were varied. Following cold storage from December to early June, the canes were tipped (cut) at 160 cm height and grown in open plastic tunnels in the fruiting season for the evaluation of growth and yield performance. Remarkable berry yields of 1.5–3.8 kg per plant (cane) were regularly achieved. When grown in the open, later starts than June 1 (June 15 and July 1) successively reduced yields. On the other hand, an earlier start involves risks of growth cessation due to low spring temperature. When grown in greenhouses, high yields were still possible when plants were transferred from propagation conditions as late as July 1, although optimal yields of nearly 4 kg per plant were obtained with transfer on June 15. In a year with unusually high summer temperatures, the yields of canes produced in the open and in greenhouses did not vary significantly, whereas in the second year with normal summer temperatures, canes produced in greenhouses consistently out-yielded those produced in the open by about 1 kg per cane. Regression analyses revealed that high yields were associated with fruiting cane architecture traits such as cane height, number and length of laterals, and a low proportion of dormant buds. The single most important component was lateral length which alone accounted for 82% of the yield variation. Since lateral lengths increased from the shoot tip towards the base, cane heights in excess of 2 m are required for the attainment of top yields as the uppermost nodes with short and low-yielding laterals then can be eliminated by tipping.     

Modeling the transport of acidity in soil profiles with front — A dynamic transport model

A dynamic transport model, FRONT, that describes the downwards transport of acidity in podzolized forest soils is presented. In this model the downward transport of acidity with the soil solution is counteracted by a production of alkalinity through the weathering of primary minerals and delayed by the adsorption of sulfate and hydrogen ions on iron- and aluminium oxides. The heart of the model is a massbalance equation that describes the transport of bulk acidity/alkalinity. The FRONT model was tested on 23 deep soil profiles situated along three transects in west-to-east direction across Sweden. Using a deposition scenario starting at 1910 the model was able to account for the large regional differences in the present depth of the acid front. Assuming a linearly decreasing deposition until 30% of present deposition is reached in 2010 the model was used to simulate a scenario for profiles in different parts of Sweden. The scenarios indicated that the upper parts of soil profiles that are severely acidified today will recover and assume a new steady-state in 2030. However, for soil profiles that have large stores of adsorbed sulfate in the B horizon the simulations indicate that one can expect an increased acidity in the deep soil layers several decades after the deposition has ceased due to downward transport of acidity.