scholarly journals Analysis of the genetic structure of a model Scots pine (Pinus sylvestris) seed orchard for development of management strategies

2013 ◽  
Vol 59 (No. 10) ◽  
pp. 377-387 ◽  
Author(s):  
O. Vanek ◽  
Z. Procházková ◽  
MatějkaK
Keyword(s):  
Genetic Structure ◽  
Scots Pine ◽  
Management Strategies ◽  
Seed Orchard ◽  
Similar Proportion ◽  
Gene Markers ◽  
Cone Production ◽  
The North ◽  
Forest Regions ◽  
Clone Identity

Genetic structure, diversity and clonal homogeneity were determined on the basis of the isozyme gene markers in a model Scots pine seed orchard in the north-eastern part of the Czech Republic that originated from natural forest regions NFR 28 and 29 (Jesen&iacute;ky Mts.) and the 2<sup>nd</sup> and 3<sup>rd</sup> forest altitudinal zones (FAZ). Clone and ramet crop variation for the 2009&ndash;2011 period was assessed. Comparing the loci measured also in two pine orchards in central Slovakia, a similar proportion of homogeneous clones but considerably lower expected heterozygosity were found out for most of the measured isozyme loci. Heterozygosity of the investigated orchard did not change considerably after the exclusion of alien and wrongly placed ramets. No difference in average cone production between clones originating from different NFR was observed. Verification of the clone identity of seed orchards managed in a certain way can be suggested with the subsequent removal of alien ramets.

scholarly journals Estimation of Clonal Variation in Seed Cone Production Over Time in a Scots pine (Pinus sylvestris L.) Seed Orchard

2009 ◽  
Vol 58 (1-6) ◽  
pp. 53-62 ◽  
Author(s):  
Johan Kroon ◽  
Ulfstand Wennström ◽  
Finnvid Prescher ◽  
Dag Lindgren ◽  
Tim J. Mullin
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Genetic Correlations ◽  
Seed Orchard ◽  
Clonal Variation ◽  
Annual Data ◽  
Single Observation ◽  
Cone Production ◽  
Seed Cone ◽  
Selection Of

Abstract Possibilities for early selection of clones for future seed cone production were studied in a clonal seed orchard of Scots pine (Pinus sylvestris L.) in northern Sweden over the first 30 years following establishment. The annual data were modelled as series of bivariate analyses. The correlations between cone production of clones in any individual year and that of a previous year, and cumulative cone production over all years were studied. The corresponding multivariate analysis for a full data fit simultaneously was best estimated with a genetic distance-based power model (AR). The genetic (variation among clones) and environmental variation were of the same magnitude. The genetic correlations were larger than the phenotypic correlations and both increased with orchard age. Basing selection of clones on a single observation at an early age to improve future cone production was not effective, but efficiency increased if cumulative cone count over many years was used. Year-to-year genetic correlations indicated that early forecasts by clone of cone production at mature ages are highly uncertain. Reliable predictions (moderate correlations) could be achieved only if based on rather mature grafts, 14 or more years after establishment.

Addressing on-farm management to enhance pasture productivity and persistence

2013 ◽  
pp. 241-244
Author(s):  
W.N. Reynolds
Keyword(s):  
Management Strategies ◽  
Dairy Farm ◽  
Stocking Rate ◽  
Pasture Management ◽  
Pasture Production ◽  
Operating Profit ◽  
The North ◽  
The Cost ◽  
On Farm ◽  
Attention To Detail

Following the 2007/08 drought, we experienced poor pasture production and persistence on our dairy farm in north Waikato, leading to decreased milksolids production and a greater reliance on bought-in feed. It is estimated that the cost of this to our farming operation was about $1300 per hectare per year in lost operating profit. While climate and black beetle were factors, they did not explain everything, and other factors were also involved. In the last 3 years we have changed our management strategies to better withstand dry summers, the catalyst for which was becoming the DairyNZ Pasture Improvement Focus Farm for the north Waikato. The major changes we made were to reduce stocking rate, actively manage pastures in summer to reduce over-grazing, and pay more attention to detail in our pasture renewal programme. To date the result has been a reduced need for pasture renewal, a lift in whole farm performance and increased profitability. Keywords: Focus farm, over-grazing, pasture management, pasture persistence, profitability

scholarly journals Understanding the Impact of Different Landscape-Level Fuel Management Strategies on Wildfire Hazard in Central Portugal

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 522
Author(s):  
Akli Benali ◽  
Ana C. L. Sá ◽  
João Pinho ◽  
Paulo M. Fernandes ◽  
José M. C. Pereira
Keyword(s):  
Management Strategies ◽  
Treatment Strategies ◽  
Fire Season ◽  
Burned Area ◽  
Treatment Area ◽  
Fuel Treatment ◽  
The North ◽  
Wildfire Hazard ◽  
Central Portugal ◽  
The Impact

The extreme 2017 fire season in Portugal led to widespread recognition of the need for a paradigm shift in forest and wildfire management. We focused our study on Alvares, a parish in central Portugal located in a fire-prone area, which had 60% of its area burned in 2017. We evaluated how different fuel treatment strategies may reduce wildfire hazard in Alvares through (i) a fuel break network with different extents corresponding to different levels of priority and (ii) random fuel treatments resulting from a potential increase in stand-level management intensity. To assess this, we developed a stochastic wildfire simulation system (FUNC-SIM) that integrates uncertainties in fuel distribution over the landscape. If the landscape remains unchanged, Alvares will have large burn probabilities in the north, northeast and center-east areas of the parish that are very often associated with high fireline intensities. The different fuel treatment scenarios decreased burned area between 12.1–31.2%, resulting from 1–4.6% increases in the annual treatment area and reduced the likelihood of wildfires larger than 5000 ha by 10–40%. On average, simulated burned area decreased 0.22% per each ha treated, and cost-effectiveness decreased with increasing area treated. Overall, both fuel treatment strategies effectively reduced wildfire hazard and should be part of a larger, holistic and integrated plan to reduce the vulnerability of the Alvares parish to wildfires.

scholarly journals Farmers’ and Herders’ Perceptions on Rangeland Management in Two Agroecological Zones of Benin

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 425
Author(s):  
Rodrigue Vivien Cao Diogo ◽  
Luc Hippolyte Dossa ◽  
Sèyi Fridaïus Ulrich Vanvanhossou ◽  
Badirou Dine Abdoulaye ◽  
Kossi Hélliot Dosseh ◽  
...  
Keyword(s):  
Natural Resources ◽  
Management Strategies ◽  
Sustainable Use ◽  
Negative Attitude ◽  
Rangeland Management ◽  
Mineral Fertilization ◽  
The North ◽  
Unused Land ◽  
Agroecological Zones ◽  
Sound Management

The sustainable use of rangelands in pastoral areas requires the inclusion of all stakeholders to develop sound management strategies. However, the role of these actors in the sustainable management of natural resources is still poorly understood. The present study aims to (i) assess the perception of farmers and herders of the risks and opportunities of transhumance on rangeland resource use and management, and to (ii) generate useful knowledge for the design and implementation of policies that favor the coexistence of these actors and reduce competition over rangeland resources use in Benin. To this end, interviews were conducted with 240 crop farmers and herders using a semi-structured questionnaire in two contrasting agroecological zones in the northern (Kandi) and the southern (Kétou) part of the country. Among the respondents, 64% of farmers in the North were agro-pastoralists (owning 10.6 ha of land and 10.7 cattle) and 36% were herders (keeping 45.8 cattle and cultivating about 3.7 ha of land). They perceived that communal rangelands were entirely degraded. In the South, 36% of respondents were agro-pastoralists (with 0.3 cattle and farming 4 ha of land) and 64% cattle herders (raising 45.3 cattle and farming 0.9 ha of land only). Of the herders, 50% kept cattle for more than 20 years, while agro-pastoralists had no previous experience in cattle herding. Cultivation practices among crop farmers, such as high use of mineral fertilization (23.8%) and bush fires for land clearing (22.5%), were reported in Kandi (North) and Kétou (South) as factors that might contribute to land degradation. However, these farmers perceived transhumance as a threat to the sustainable use of natural resources. In contrast, herders perceived transhumance as an opportunity to valorize unused land and increase the availability of manure to cropland. The prevalent negative attitude of crop farmers regarding transhumant herders increases the vulnerability of cattle herding in both regions. There is an urgent need of raising awareness concerning the mutual benefits provided by the coexistence of crop farmers with herders to promote participative rangeland management strategies. This may contribute towards coping with the current challenges of food insecurity and increasing climate variability as well as to reducing recurrent conflicts in the region.

Survival and cause-specific mortality of the female eastern wild turkey at its northern range edge

2014 ◽  
Vol 41 (7) ◽  
pp. 545 ◽  
Author(s):  
Britney Niedzielski ◽  
Jeff Bowman
Keyword(s):  
Management Strategies ◽  
Meleagris Gallopavo ◽  
Limiting Factors ◽  
Wild Turkey ◽  
High Productivity ◽  
Supplemental Food ◽  
Range Edge ◽  
The North ◽  
Wild Turkeys ◽  
Peripheral Areas

Context In an era of rapid environmental change, many species are shifting their distributions. As temperate-zone species’ expand their ranges north, different and potentially severe limiting factors may begin to affect their ability to survive and reproduce. The wild turkey (Meleagris gallopavo) is one example of a species undergoing rapid northern expansion. Aims An improved understanding of wild turkey demography at the species’ northern range periphery would facilitate effective management of this important game species. Therefore, we undertook a study to evaluate survival, causes of mortality, and behavioural strategies that may govern survival of female wild turkeys. Methods We captured 53 female wild turkeys, and used backpack transmitters to monitor their individual fates during 2012–13. Key results The annual survival estimate was 0.37 (95% CI: 0.25–0.55), with the lowest seasonal survival in the winter. The most frequent cause of mortality was mammalian predation, predominately by coyotes (Canis latrans). Age, proximity to supplemental food, and habitat use did not affect risk of mortality. Conclusions Northern wild turkeys in our study exhibited lower survival and suffered higher predation than did populations in the species’ historic range. Despite our findings, the wild turkey has expanded its range northwards and continues to exist in these peripheral areas. This may be due to high productivity or a source–sink dynamic, whereby high mortality is offset by immigration from the south. Implications The low survival and high predation of wild turkeys in the north must be considered when developing management strategies, particularly if interest exists in translocating turkeys farther north. Further research is needed to better understand whether northern turkey populations persist as sinks.

Gibberellin A4/7 enhances seed-cone production in field-grown black spruce

1988 ◽  
Vol 18 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Rong H. Ho
Keyword(s):  
Vitamin E ◽  
Black Spruce ◽  
Seed Orchard ◽  
Shoot Elongation ◽  
Bud Burst ◽  
Lateral Shoot ◽  
Cone Production ◽  
Seed Cone ◽  
Vegetative Bud ◽  
Needle Primordia

Black spruce (Piceamariana (Mill.) B.S.P.) grafts growing in a seed orchard were sprayed with gibberellin A4/7, and grafts and trees in families growing in arboreta were sprayed with gibberellin A4/7 and (or) vitamin E from vegetative bud burst to the end of shoot elongation. Gibberellin A4/7 was very effective in promoting seed cones and 400 mg/L appeared optimal. Vitamin E at 1000 mg/L was not effective. Vegetative bud burst occurred in mid-May and shoot elongation ended in late June. Needle primordia were visible on the apices of newly formed buds at the end of June. Reproductive buds had fewer bud scales than vegetative buds. It appeared that potential reproductive buds terminated their bud scale initiation earlier. Gibberellin A4/7 application to promote seed-cone production should be carried out before bud-type differentiation. This coincides with the end of lateral shoot elongation.

scholarly journals Reproductive phenology of the American Bullfrog in subtropical Brazil: photoperiod as a main determinant of seasonal activity

2016 ◽  
Vol 88 (3 suppl) ◽  
pp. 1909-1921 ◽  
Author(s):  
CAMILA I. MEDEIROS ◽  
CAMILA BOTH ◽  
IGOR L. KAEFER ◽  
SONIA Z. CECHIN
Keyword(s):  
Life Histories ◽  
Management Strategies ◽  
Reproductive Activity ◽  
Ex Situ ◽  
Reproductive Phenology ◽  
High Fertility ◽  
Seasonal Activity ◽  
Population Declines ◽  
American Bullfrog ◽  
The North

ABSTRACT The North American bullfrog Lithobates catesbeianus continues to invade ecosystems worldwide, potentially causing population declines and even extinctions. Within its native distribution, bullfrogs show prolonged reproductive seasons and high fertility. However, data on breeding biology of bullfrogs ex-situ in invaded localities mainly comes from anecdotal reports. Understanding how invasive species are adjusting their life histories to new colonized environments is important for conservation purposes. Here we describe temporal and spatial abundance, calling activity, spawning and tadpole distribution of bullfrogs in southern Brazil. Eighteen samplings occurred during one year. The abundance of individuals was positively related to longer photoperiods and higher temperatures. Reproductive activity was also positively associated with longer photoperiods. Calling sites, spawning and tadpoles were associated with microhabitats presenting hydrophytes, which may provide shelter and thermal stability to bullfrogs. The reproductive seasonal activity of bullfrogs can be highly variable across its growing geographical range, but in subtropical Brazil it is associated with photoperiod, a highly predictable abiotic determinant. In our study area, bullfrogs presented a breeding season twice as long as that observed in some native localities. We suggest that management strategies directed to bullfrog populations must consider the habitat structures and seasonal regimes determined by each invaded environment.

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