Bracken Rhizomes Research Articles

Planting in Paradise

The One Billion Trees project is an initiative led by the Ministry of Primary Industries where they aim to plant 1 billion trees by the year 2030 to transform New Zealand forests in a way that improves the productivity of the land, as well as helping the natural environment. Notably, a large proportion of the trees that have already been planted and established are Pinus radiata (exotic pine trees) which have a detrimental effect on the natural environment due to outcompeting native flora and compromising soil stability due to their shallow root systems. P. radiata are a fast establishing and cost effective option for landowners and farmers that are participating in the One Billion Trees project. Our project's aim was to understand what is required to support the establishment of native beech trees, using both on-campus and field trials, with a primary focus on assessing methods of delivering mycorrhizal inoculation to native beech seedlings. This would allow us to educate the Ministry of Primary Industries and to provide these landowners and farmers with information on how to regenerate their land using native trees instead of exotic. The field trial, located within the Motutapu Covenant at Mahu Whenua, incorporated various treatment options, such as planting beech with or without bracken rhizomes, Manuka seeds, Manuka duffpods, and beech duffpods. The on-campus trial was established in a controlled environment where beech and Manuka seeds were planted with or without their respective duffpods. Currently the results of these experiments are inconclusive, requiring additional time to observe the effects of different treatments on the planted seedlings and seeds which will in future contribute to sustainable and effective reforestation practices using native trees. Project Funded by: The Ministry for Primary Industries and The University of Otago

Natural Regeneration after Long-Term Bracken Fern Control with Balsa (Ochroma pyramidale) in the Neotropics

In many parts of the Neotropics, deforested areas are often colonized by the highly competitive invasive bracken fern (Pteridium aquilinum), which inhabits naturally regenerated forests and successional forests on abandoned farmland. Within the tropical forest region of Chiapas in southern Mexico, we implemented an experiment in 2005 to out-compete bracken fern infestation and reduce or eliminate live bracken rhizomes using several treatments: Direct sowing of balsa seeds (Ochroma pyramidale; Malvaceae), a traditional Lacandon treatment of scattering balsa seeds, transplanting balsa seedlings, and a control treatment (without balsa). For each treatment, we applied three different bracken weeding frequencies: No weeding, biweekly weeding, and monthly weeding. In this study, we present data gathered four years after establishing the experiment regarding: Bracken fern rhizome biomass, balsa density, basal area, height, density, species richness of naturally regenerating vegetation for all treatments, and bracken weeding frequencies. We also evaluated the importance of balsa and its regenerative attributes in controlling bracken fern by correlating it with remaining belowground live rhizome biomass. Living rhizome biomass was completely eradicated in all treatments with biweekly and monthly weeding. Density and species richness of a naturally regenerated species were negatively correlated with bracken fern rhizome biomass, and the density of this species was highest in areas with no rhizome biomass. Although balsa tree stands are effective short-term solutions for controlling rhizome biomass, the success of natural regeneration following balsa establishment can be critical to long-term elimination of bracken fern.

Fast‐growing pioneer tree stands as a rapid and effective strategy for bracken elimination in the Neotropics

Summary Large areas of agricultural land around the world are degraded as a consequence of dominance by bracken fern (Pteridium spp.). Tropical production systems based on shifting cultivation and cattle breeding are particularly vulnerable to invasion of this species. In spite of this, effective methods for tropical bracken control are limited. Fast‐growing tree species have been used successfully to out‐compete aggressively colonizing heliophytes and trigger natural succession. Drawing on a traditional Mayan management technique, we evaluate the potential of the pioneer tree balsa (Ochroma pyramidale) to control Pteridium caudatum in Chiapas, Mexico. We tested different bracken cutting frequencies and balsa propagation methods in a factorial randomized block experiment. Eighteen months later, we quantified bracken biomass under the young balsa canopy. Living bracken rhizome biomass correlated significantly with balsa basal area, leaf litter biomass and understorey light intensity. While bracken rhizomes persisted in control plots, it was completely eradicated in plots with a minimum balsa basal area of 11 m2 ha−1. This threshold value was reached in less than 18 months with any of the tested propagation methods (seed broadcasting, direct sowing or nursery seedlings), on the condition of at least monthly bracken cutting during the first six months. The ability of fast‐growing broad‐leaved pioneer trees like balsa to quickly out‐compete bracken fern offers opportunities for large‐scale application in tropical rural areas where economic and technical resources are scarce. Synthesis and applications. Mayan subsistence farmers traditionally use balsa to out‐compete invasive weeds, including bracken fern. Here, we highlight the usefulness of this method for quick and effective bracken control in southern Mexico. This approach, in combination with balsa's short rotation cycle, creates opportunities to rapidly convert bracken land into forest stands with commercial potential, thus providing local income and increasing the likelihood of adoption by rural people. We encourage further research to test the potential of balsa and other fast‐growing pioneer trees species for controlling bracken and similar weeds.

Control of bracken and restoration of heathland. VII. The response of bracken rhizomes to 18 years of continued bracken control or 6 years of control followed by recovery

1. The effects of six bracken control treatments applied in combination with a Calluna* seeding treatment on the rhizome system of bracken Pteridium aquilinum at Cavenham Heath in Breckland was assessed after 18 years. Bracken control included cutting once and twice yearly between 1978 and 1996; spraying the herbicide asulam at the recommended rate (4·4 kg a.i. ha−1) in two treatments (1978 and 1978 plus 1979), each followed by repeat doses in 1984 and 1990, and spraying asulam followed by cutting once yearly. After 6 years the experiment was split and bracken control was continued/reapplied on half the plots and stopped on the remainder. The effects of treatment on the numbers of active and dormant buds and the length and biomass on both frond‐bearing and storage rhizomes were measured. 2. When applied continuously over the 18 years, all treatments reduced all rhizome measures, but treatments that included cutting were more effective than ones that just used asulam. The best treatment after 10–12 years was cutting twice yearly, but after 18 years this treatment had apparently reached an equilibrium and the cutting‐once‐yearly treatment was superior. No treatment eradicated the bracken in 18 years of continuous treatment. 3. When bracken control treatments were stopped after 6 years rhizome recovery started within 4 years and there was significant recovery thereafter. After 12 years the least effective treatment, cut once yearly, although still showing a significant reduction in rhizome biomass, had recovered to 88% of the untreated plots. The most effective treatment was cutting twice yearly for 6 years, where most measures of rhizome performance remained at approximately 50% of untreated plots 12 years after cutting stopped. 4. Regression analysis was used to investigate the relationship between frond production and rhizome characteristics. Rhizome biomass, especially of the storage rhizome component, was consistently the most important variable; frond bud numbers were less important. 5. Simple models, developed making assumptions that the response of the rhizome to treatment is linear through time, have been shown to be invalid over the longer time period. This is because the impacts of the treatments reduce through time. 6. These results are discussed in relation to long‐term bracken control and the assessment of bracken stocks. If bracken is to be suppressed on a long‐term basis a continuous control strategy is needed. It is unlikely that complete eradication will be possible with current control technology. The long time scale found for the total recovery of the bracken from only 6 years of treatment (>12 years) means that the large areas of bracken that have been treated in the past will take some time to recover to pretreatment levels. This recovery is an unknown factor in bracken stock assessments.

Control of Bracken and the Restoration of Heathland. IV. Effects of Bracken Control and Heathland Restoration Treatments on Nutrient Distribution and Soil Chemistry

1. The effects of treatments to control bracken and to restore either Calluna heath or grassland on the amounts of bracken rhizomes, the distribution of nutrients in the vegetation, and selected aspects of soil chemistry, were studied. 2. The effects of the bracken control treatments on bracken rhizomes were similar to those reported earlier for midsummer bracken-frond yields. The most successful treatment was cutting bracken twice yearly for at least 10 years, which reduced frond-bearing rhizomes to 2-4% and storage rhizomes to 8-11% of untreated levels. 3. There were differences in the amounts of nutrients found in the bracken rhizomes and litter in the untreated plots at the two study sites. The maximum potential flux of nutrients to the soil was lower for some elements in plots with maximum heath development or bracken recovery, but for other elements no significant effects were found. 4. There were a few significant differences in soil chemical properties between the different management treatments, but they were difficult to interpret. There was no evidence of any reduction in soil chemical properties in these experiments where Calluna heath and grassland have re-established. If soil fertility is to be reduced during such restoration schemes this problem needs to be addressed further.

Nutrient status of bracken ( Pteridium aquilinum) following whole-tree harvesting in Upper Michigan

Mineral nutrient status and biomass production of bracken, Pteridium aquilinum (L.) Kuhn, fronds and rhizomes were quantified immediately following a whole-tree harvest in Upper Michigan. Multiple sampling occurred between full leaf expansion and senescence to monitor mineral translocation from the fronds to the rhizomes, as well as differences in bracken mineral content between harvested and unharvested control sites. Bracken rhizomes on the harvested site had significantly higher concentrations of phosphorus, potassium and magnesium than the control site. Frond biomass production was lower on the harvested site, while rhizome biomass production showed no differences between sites. Rhizome P contents were significantly higher on the harvested site. Translocation of mineral elements from the fronds to the rhizomes during senescence was monitored. Nitrogen, P, and K were readily translocated, while Mg and calcium were not. The larger amounts of nutrients present in the rhizomes on the harvested site suggest increased nutrient uptake and, therefore, nutrient conservation by bracken may occur on a harvested site.

Comparison of three methods of thiamine supplementation by measurement of urinary thiamine excretion in sheep

The relative efficacy of thiamine supplementation to sheep by injection, subcutaneous implant and orally administered protected thiamine bolus was compared in two experiments using a grass and hay ration and a ration containing bracken rhizomes to induce thiamine deficiency. In both experiments, urinary excretion of thiamine was significantly higher in supplemented sheep than in the controls, and in sheep supplemented by injection than in sheep supplemented by implant or protected boluses. Thiamine excretion was lower in sheep fed the ration containing bracken rhizomes than in sheep fed the grass ration.

Nucleotides and related compounds in bracken

The role of sugar nucleotides in polysaccharide synthesis is discussed. The presence of acid soluble nucleotides in bracken rhizomes was demonstrated (20 μmol/kg fresh weight) and the uridine series was shown to predominate accounting for some 80% of the total. The following were identified, UDP-glucose (60%), UDP-galactose (15%), UDP-xylose (9%), UDP-arabinose (3%), UDP-glucuronic acid (4%), GDP-mannose (6%) and GDP-fucose (3%). It is probable that these sugar nucleotides supply the full complement of sugars identified in the carbohydrate fractions of bracken.

Induction of thiamine deficiency in sheep, with lesions similar to those of cerebrocortical necrosis

Acute thiamine deficiency was induced in adult sheep by the inclusion of a potent source of thiaminase I in the form of low temperature dried, milled bracken rhizomes in the diet. Autoclaving the rhizome powder abolished its capacity to induce avitaminosis B 1 and also inactivated the enzyme. The rhizome powder destroyed about 80 μg. thiamine per minute per gram, and the minimum quantity required was 15 to 25 per cent. by weight of the pelleted diet. When the plant source of thiaminase I formed 25 to 33 per cent. of the ration, symptoms took from 25 to 40 days to develop—roughly the time required in simple-stomached animals. Decreasing the concentration to 15 per cent. prolonged this time to 3 months, whilst a 5 per cent. level did not produce the disease. Thiaminase I activity was present in the contents from all parts of the alimentary tract and faeces of sheep fed the rhizome diets. Even when the enzyme concentration was insufficient to cause the clinical syndrome, animals did not thrive as well as sheep fed on similar diets in which the thiaminase I had been inactivated. Sheep made thiamine deficient in this way exhibited all the biochemical and clinical features characteristic of thiamine deficiency in homogastric animals; the response to thiamine therapy was dramatic in the early stages. The clinical features and histopathology resembled those of field cases of cerebrocortical necrosis in sheep. The results support the view that cerebrocortical necrosis is a “thiaminase disease” of ruminants.

Studies on nucleotides and related compounds in plants. V. Isolation and identification of bracken nucleotides

AbstractThe presence of acid‐soluble nucleotides was demonstrated in bracken rhizomes. Cold trichloroacetic acid extracts of bracken had to be submitted to some eight purification steps prior to analysis. Of the nucleotide material held by an anion exchange resin uridine derivatives (UMP, UDP‐glucose, UDP‐galactose, UDP‐xylose, UDP‐arabinose, UDP‐glucuronic acid and a trace of UDP) accounted for some 80% of the total. The remainder comprised guanosine (12%; GMP, GDP‐mannose and GDP‐fucose) and adenosine (8%; mainly ATP) compounds.A comparison of the sugar composition of the nucleotide material with that of associated soluble carbohydrates present in the rhizome (mucilage, glycoside and sucrose) is also included.

Comparative study of carcinogenic activity in each part of bracken.

The carcinogenic activity of the curled tops and stalks of the young bracken fronds and also of the fronds and rhizomes was compared in inbred strain ACI rats. Rats received the pellets containing the curled tops or the stalks of bracken fronds for 2 months. In another experiment, rats were fed the pellets containing the bracken fronds or rhizomes for 4 months. A control group was fed a normal diet. Carcinogenic activity was observed in each part of the bracken, and tumors were most frequently induced in the ileum. In rats given the curled tops, the incidence and multiplicity of the intestinal tumors were higher than in those receiving the stalks. Furthermore, in rats fed the pellets containing the bracken rhizomes, the latent period of the tumor was shorter and the multiplicity was much higher than in those given the fronds. However, the starch from the bracken rhizomes was not carcinogenic. Conceivably the bracken carcinogen was water soluble and washed away in the preparation process. These results showed that the carcinogenic activity of the curled tops of the young bracken fronds was stronger than that of the stalks and that the carcinogenic activity of the bracken rhizomes was stronger than that of the young frond.

Experimental poisoning by bracken rhizomes in pigs.

Experimental poisoning by bracken rhizomes in pigs.

Effects of bracken rhizomes on the pig

Effects of bracken rhizomes on the pig