Dry Forest Conditions Research Articles

Влияние рубок ухода на биологическую устойчивость сосняков защитного назначения Северного Казахстана

The article presents the results of thinnings in pineries of the Kazakh uplands in Northern Kazakhstan carried out for an over 70-year period and their influence on biosustainability (on the example of the state national natural park «Burabay»). The research objects are high-density mature pine forests growing in dry forest conditions. The results of research have shown that to the average values of the vital status indicator (VSI), the complex estimated indicator (CEI) and the tree slenderness coefficient (H/D), pine stands in most sections are characterized as «weakened». In forest stands after thinning of strong and very strong intensity of thinning in terms of tree slenderness coefficient (H/D) the pine forests is assessed as healthy. It is proved that the vital status maximum credible indicators of the pine forests and the implementation of forestry practices in them is the tree slenderness coefficient. The largest number of trees (up to 70 % of the total number of trees) with tree slenderness coefficient an H/D value of less than 100 in the pine forest after very high intensity thinning is evaluated. A large number of trees with H/D < 100 in the forests proves a weak competition between trees in the forests and higher resistance to natural and anthropogenic factors are proved. The data obtained show a positive effect of strong thinning on the increase in the radial growth of pine trees. For formation of sustainable pine forests in dry growing conditions in Northern Kazakhstan with thinning one-two steps with 26–35 % of the stock volumes destruction at the age of 25–30 years and 40–50 years, and with subsequent increment felling in them is recommended.

Effects of supplementation with tropical dry forest tree foliage on meat quality and fatty acid composition in Colombian creole lambs (ovis aries)

In tropical dry forest conditions, small ruminant production is an alternative for small farmers. Even so, the quality of the forages does not meet the nutritional requirements of the animals. However, the high biodiversity of trees that exist in the region offers a supplementation alternative especially during the dry season. The objective of this research work was to evaluate the quality and the profile effect of fatty acids in Colombian creole lamb meat supplemented with tree species from the tropical dry forest. A total of 35 lambs were used which were randomly distributed in 5 treatments as follows: T1: Botriochloa pertusa; T2: Botriochloa pertusa + 300 g/day of Leucaena leucocephala; T3: Botriochloa pertusa + 300 g/day of Gliricidia sepium; T4: Botriochloa pertusa + 300 g/day of Guazuma ulmifolia and T5 (BpSs): Botriochloa pertusa + 300 g/day of Senna spectabilis. The experimental units were brought to a final slaughter weight of ±32 kg and the pH, color, and fatty acid composition of the carcasses were evaluated at 24 hours. The meat quality parameters did not present significant differences (P>0.05) in the different supplements and obtained acceptable parameters for their consumption.It was evidenced that the proportions of saturated fatty acids (C 16: 0, C 18: 0, total SFA) in lambs supplemented with Senna spectabilis and Gliricidia sepium were lower (P<0.05). It is concluded that under the conditions of the study the supplementations with Senna spectabilis and Gliricidia sepium can induce a favorable change in the fatty acid content of lamb meat.

In situ assessment of Jatropha curcas germplasm under tropical dry forest conditions in Manabí-Ecuador

Jatropha germplasm accessions need an assessment of their traits to evaluate the nature and magnitude of the genetic variability among accessions. The objective of this research was to evaluate the phenotypic behavior of 130 Jatropha curcas L. (Jatropha) accessions and the genetic variability of selected Jatropha accessions. The selected variables were assessed between 2008-2014 based on the number of fruits per tree (FP), the number of seeds per fruit (SpF), weight of 100 dry seeds (100SW), seed length (SL), seed width (SW), smallest deviation standard as regular seed production (RP), highest deviation standard as irregular seed production (IP), seed oil content (Oil), seed production in g per tree (SP). Correspondence Analysis techniques were also applied in selected elite Jatropha accessions. The genotypic and phenotypic correlation coefficient between seed length, seed width, 100-seed weight and oil content for selected Jatropha accessions were applied. Variance, genotypic and phenotypic coefficients of variation, heritability (broad-sense) and genetic advance were calculated for several Jatropha phenotypic characteristics. CP041, CP052, CP037, CP054, CP060, CP122, CP118, CP120, CP121 INIAP Jatropha accessions were selected basically for SP and FP. A high statistically significant correlation (genotypic and phenotypic) between seed length – seed width was obtained from the chosen Jatropha accessions. Genetic association in the characteristics of growth and production highlighted the low phenotypic diversity in the Jatropha Portoviejo Research Station (EEP) of the National Institute for Agricultural and Cattle Ranching Research (INIAP) germplasm bank. There is an urgent need to improve the germplasm resource by obtaining new accessions, mainly from countries considered as centers of origin of the species.

Evaluation of the efficacy of neonicotinoid and pyrethroid insecticides in Diaphorina citri Kuwayama (Hemiptera: Liviidae) populations in Colombia

The Asian citrus psyllid Diaphorina citri is the insect vector of the disease known as huanglongbing (HLB), which is the most devastating disease of citrus crops in the world. The Asian citrus psyllid was officially reported in Colombia in 2007, and a national phytosanitary emergency was declared because of the presence of HLB in 2015. Two different experiments were carried out in two locations (Apulo and Jerusalén, Department of Cundinamarca) in Colombia to evaluate the effectiveness of neonicotinoid (clothianidin, imidacloprid and thiamethoxan) and pyrethroid applications (bifenthrin, deltamethrin and lambda cyhalothrin) on the control of D. citri populations (adults, nymphs and eggs) in ‘Tahiti’ lime trees established under tropical dry forest conditions. In the first experiment, trees were foliarly treated as follows: (1) untreated trees; (2) trees treated with 100 g ha-1 of imidacloprid; (3) trees treated with 60 g ha-1 of bifenthrin; (4) trees treated with 12.5 g ha-1 of deltamethrin and (5) trees treated with a co-formulation of 70 g ha-1 of a neonicotinoid (thiametoxan) and 53 g ha-1 of a pyrethroid (lambda cyhalothrin). In the second experiment, trees were treated with 100 g ha-1 of clothianidin. Foliar insecticide applications were carried out at 0 and 4 weeks after the initiation of treatments (WAT). In the first trial, the control presented a mean number of individuals per flush of ≈1.14, whereas the trees treated with neoinicotinoids and pyrethroids showed 50% fewer individuals (0.53-0.61). For the population of immatures, the number of nymphs was 2.25 nymphs per flush in the control, as compared to 0.82-1.22 individuals observed in the treatments with insecticides. The mean number of eggs was also between 80-100% higher in the control trees (2.37 individuals), as compared to the treated trees (1.14-1.78). In the second trial, the use of clothianidin showed a higher control of eggs. The results suggest that the rotation of neonicotinoids with pyrethroids can be a tool to reduce populations and delay resistance processes in D. citri in citrus trees established under tropical dry forest conditions in Colombia.

Морфо-анатомічні показники хвої Pinus pallasiana D. Don. у різних лісорослинних умовах протиерозійного насадження

<p>The paper studies morpho-anatomical parameters of the needles of <em>Pinus pallasiana</em> D. Don. in different forest growth conditions of the antierosion afforestation in the steppe Prydniprovya. The research objects are 25-27-year-old plants, which grow in cross-sectional rows on the northern slope of wooded ravine Viyskovyi. The test Plots differ in forest growth conditions especially in the extent of water supply.In spite of the relatively high drought tolerance of <em>P. pallasiana</em>, such morphometric indices of needles as length, width and thickness are reduced in dry forest conditions. Quantitative changes in a number of indicators of the structural elements of the anatomical structure of the needles indicate adaptive changes to the lack of moisture. The formation of needles in dry forest conditions causes the formation of a thicker cuticle, an increase in the thickness of the cells of the epidermis and the hypodermis (radially in the transverse section), which reduces the loss of moisture. However, reducing the size of the conducting beams limits both the flow of water into the needle and the outflow of assimilates. In arid growing conditions, the number of resin canals in needles is reduced compared to plants of thalweg, the layer of folded parenchyma, both the adaxial and abaxial parts of the needles, is thinned.</p>

Jumping the Break: Wildfires and the Logic of Separation

Jumping the Break:Wildfires and the Logic of Separation Eva-Lynn Jagoe (bio) The smoke from the fires in British Columbia and Alberta obscure our views out over the valley. Each day we grimace to each other as we gesture out the windows of Vistas Cafeteria. The vista is not of the usual snow-capped mountains. The snow melted on them weeks ago anyway. The grass is dead, and the forests are pale and yellow-tinged. When we peer through the hazy, orange-tinged, thick air, we can't even see the edge of the Banff Centre for the Arts and Creativity campus. I'm scared, but not because I think that the fires will force us to evacuate and jettison the five-week Banff Research in Culture residency program that I co-organize. I don't fear for my own personal safety, nor do I think that the fires will impinge upon daily life in tangible ways. It's more nebulous than that: it's about the smoke and its threat, the way the sun looks like a round orange ball hanging in the middle of an orange-brown haze, which smacks of so many postapocalypse films. The smoke is sharp in our nostrils and catches at the back of our throats, making our eyes water and causing us to look and feel as if we're crying. We're not crying, though. We're all a little excited by the smoke and discuss it constantly. It's a new version of chatting to acquaintances about the weather. The discussion functions as a barometer of political leanings as well. If someone connects the natural [End Page 231] disasters to the predicted outcomes of climate change, then I know that he or she is on my side. The foes are the ones who don't make the connections or don't care, such as that wealthy donor who came to the Banff Centre for the fund-raising gala. I heard her, in the same conversation, bemoan the dry forest conditions that had the park on high-danger fire alert and express the hope that it wouldn't rain over the weekend and wreck the women's ball gowns. Was her imagination not filled, like mine, with climate-fiction scenarios of the drought, fire, flooding, and extreme heat that global warming would cause in this century? Obviously there were two separate registers in her brain that kept the social separate from the environmental. It is one thing to argue in theory about how we have irrevocably changed the planet through human actions. It is another to experience the repercussions firsthand instead of reading about them as events that happen elsewhere. The psychological effects are uncanny, evoking contradictory emotions, memories, and apprehensions. For so many of the people I have talked to, their first instinct was to like the smell. It recalled backpacking adventures, cabins in the woods, and the camaraderie of bonfires. For me, the first pungent whiff took me back to the Catalan mountains of my childhood summers, where the view from the top floor of the old farmhouse sometimes contained plumes of smoke and helicopters filled with Mediterranean seawater to douse the flames. Fires weren't just in the neighboring mountains. They were also in the back of the house, where the gardener would burn all our trash once a week, never separating cardboard from plastics or from leaves and clippings. We children loved the smell of the black smoke that would gust into the playroom, not knowing the toxic fumes it contained. One afternoon when the sobremesa of adult gossip was going on too long, my cousin and I asked to be excused from the dining room. We stood there aimlessly in the oppressive heat, our fingers rubbing deep between the shoulder blades of the panting sheep-dogs. Suddenly my cousin gasped and pointed in the direction of the chicken coop. We ran closer and saw thick smoke coming from the grass on the other side of the wall. "¡Incendio! ¡Incendio!" (Fire! Fire!) we called out, and the adults, groggy from overeating and wine, came running. There in the midst of the burning fire was Jaume, the gardener...

Variation in seed production of Jatropha curcas L. accessions under tropical dry forest conditions in Ecuador

The Ecuadorian Government has, since the end of 2011, promoted an initiative for using pure jatropha oil, derived from the seeds of Jatropha curcas L., to generate electricity to supply Floreana Island (one of the Galapagos Islands). In the present study, nine elite accessions of J. curcas from tropical dry forests in Ecuador were cultivated for the purpose of evaluating seed production in relation to the propagation method used (seed, cutting). A split-plot design with three replicates was applied. Seed production, measured over a period of 7 years (2009–2015) showed a large year-to-year variation. However, seed production varied significantly among accessions and depended on the propagation method (seeds or cuttings). Propagation by stem cuttings stabilized the variability in the vegetative and seed production components measured, increasing the strength of their relationships with seed yield. The three highest yielding accessions produced 0.28–0.30 kg of seeds tree−1 year−1. As seed yield was not correlated with annual precipitation, the year-to-year variation in production of accessions indicates the effect of other factors not considered here, such as agronomic practices. The study findings suggest that agroforestry practices could be developed that would enable J. curcas to play a predominant role in a strategy for tropical dry forests aimed at reducing poverty (also known as pro-poor growth strategy).

Novelty and Its Ecological Implications to Dry Forest Functioning and Conservation

Tropical and subtropical dry forest life zones support forests with lower stature and species richness than do tropical and subtropical life zones with greater water availability. The number of naturalized species that can thrive and mix with native species to form novel forests in dry forest conditions in Puerto Rico and the US Virgin Islands is lower than in other insular life zones. These novel dry forests are young (<60 years) with low structural development, high species dominance, and variable species density. Species density is low during initial establishment and increases with age. At the 1-ha scale, novel forests can have greater species density than mature native forests. Species groups, such as nitrogen-fixing species, and other naturalized species that dominate novel dry forests, have a disproportional influence on forest element stoichiometry. Novel dry forests, compared to the mean of all forest species assemblages island-wide, tend to have fallen leaf litter with lower than average manganese and sodium concentrations and lower than average C/N and C/P ratios. After accounting for significant differences in stand age, geology, and or precipitation, novel dry forests compared to native dry forests have higher C anomalies, lower Ca and Na anomalies, and lower C/N ratio anomalies. Taken together, these characteristics may influence litter decomposition rates and the species composition, diversity, and food web dynamics in litter and soil. Novel dry forests also contribute to the conservation of native plant species on highly degraded lands.

Reproductive behavior of crossbred dairy cows grazing an intensive silvopastoral system under tropical dry forest conditions

ABSTRACT It is widely accepted that selection for high milk yield in dairy cows has negatively affected their reproductive performance. After calving, dairy cows experience a nutritional imbalance due to an asynchrony in the occurrence of the lactation and dry matter intake peaks. In the tropics, this situation is exacerbated due to poor quality and/ or availability of the diet. A study was carried out to describe the nutritional and reproductive behavior of two-to-four parturition crossbred cows (Gyr (Bos indicus) x Holstein (Bos taurus)) divided in two groups according to their calving to first service interval (CFSI): Group 1: ≤50 days CFSI, n=7; Group 2: ≥50 days CFSI, n=8. Animals were grazing in an intensive silvopastoral system (ISS) based on Leucaena leucocephala and Cynodon plectostachyus and also received protein, energy and mineral supplementation. Dry matter (DMI) and nutrient intake were individually estimated and correlations between reproductive and nutritional parameters were performed. Additionally, serum progesterone concentration was monitored. Group 2 had greater forage and total DMI and milk production than Group 1 (P<0.05). Hence, Group 2 had greater nutrient intake from forages than Group 1 (P<0.05). Group 1 had a positive nutritional balance and an optimum reproductive performance compared to Group 2, which had a negative energy balance and lengthier days with open intervals (P<0.05). It was corroborated that protein and energy are required in adequate levels, to ensure that uterus undergoes involution correctly and ovarian activity starts soon in the postpartum period.

CLIMATE-TREE GROWTH RELATIONSHIPS OF Mimosa tenuiflora IN SEASONALLY DRY TROPICAL FOREST, BRAZIL

Mimosa tenuiflora is a native pioneer tree from the Caatinga used commercially as firewood due to its high calorific value. It is deciduous, its trunk does not reach large diameters and it has good regrowth capacity. This study intended to determine the annual increment in diameter of M. tenuiflora and its correlation with rainfall, as basis for fuel wood management. Disks from the stem base of M. tenuiflora trees were collected in 2008 in Sertânia and Serra Talhada, Pernambuco State, from regrowth of trees coppiced in 2003 and in Limoeiro do Norte, Ceará State, from a plantation established in 2002. The trees have well-defined annual growth rings, highly correlated with annual precipitation and are well-suited for dendrochronological investigations. Forest managers must consider the influence of previous drier years in the wood production when predicting fuel wood harvesting. The high growth correlation with the previous year's rainfall in regions where the rains start after photoperiodic stimulation indicate the necessity of understanding the growth dynamics of the species under dry forest conditions through additional ecophysiology studies.

Влияние фитомелиорантов на лесорастительные свойства почв и рост культур сосны обыкновенной в боровых условиях

Biological reclamation by plants with nitrogen-fixing symbionts and enriching the soil with organic substances is an urgent problem for the Republic of Mari El, where sod -podzolic loam, sandy loam and sandy soils with low organic content, nitrogen and other important elements was expanded. The feasibility of establishing a pine culture with the introduction of soil-improving plants was noted by many researchers, but their impact on the effectiveness of silvicultural properties of the soil, physiological processes and growth are poorly understood. In this paper we evaluated the influence of soil reclamation plants on silvicultural properties of soils, the intensity of the basic physiological processes and growth index of Scots pine. According to research, the perspective and cost-effective measure for improving the fertility of poor sandy coniferous soil, improving resilience and productivity of pine plantations is the introduction of the common juniper and soil reclamation plants with nitrogen-fixing symbionts, such as Russian broom, perennial lupine. When choosing the plants we should recognize its water regime. At the conditions of sufficient moisture it is suitably administered to the cultures of Scots pine, common juniper and perennial lupine. In the dry forest conditions the most effective is an introduction the culture of Scots pine, Russian broom. At the same time, the porosity of the soil increases from 47 to 52% and the content of humus and nitrogen by rises to18-20%.

The Interior Northwest Landscape Analysis System: A step toward understanding integrated landscape analysis

The Interior Northwest Landscape Analysis System (INLAS) project demonstrated a method for assembling teams of scientists to conduct integrated landscape analyses at the mid- or subbasin scale in the interior Northwestern United States. A state and transition modeling system (STM) with transition probabilities calibrated by using a stand-level silvicultural model to estimate rates of vegetative change was used as a central vegetative “modeling engine.” It connected to a variety of resource-related models including: wildlife habitat quantity, insect activity, grazing by ungulates, timber management, and wood utilization potential. Where appropriate, the study team examined other vegetation modeling approaches including an optimization approach based on heuristic methods and modifications to an existing stand-level projection tool, which was integrated with existing fire and insect behavior models. The STM approach provided a relatively simple interface for most resource models. These were connected to examine the influence of vegetative succession, natural disturbances, and management over a 100–200-year horizon under three management scenarios: (1) background natural disturbance, (2) fire suppression only, and (3) active fuel management. Taken all together, the results suggest to us: (1) maintaining abundant large-tree multistoried structure in cool, moist forest conditions is likely to be difficult, (2) both active fuel treatment and passive management scenarios increased the proportion of large-tree single-story forests in dry forest conditions, and (3) fire suppression only was least effective in producing and maintaining these “legacy” structures in either dry or moist forest conditions.