Is magnesium deficiency the major cause of needle chlorosis of Pinus taeda in Brazil?

Needle chlorosis(NC)in Pinus taeda L.systems in Brazil becomes more frequent after second and third harvest rotation cycles.In a study to identify factors contributing to yellowing needle chorosis(YNC),trees were grown in soils originating from contrasting parent materials,and soils and needles(whole,green and chlorotic portions)from 1-and 2-year-old branches and the first and second needle flush release at four sites with YNC on P.taeda were analyzed for various elements and properties.All soils had very low base levels(Ca^(2+),Mg^(2+)and K^(+))and P,suggesting a possible lack of multiple elements.YNC symptoms started at needle tips,then extended toward the needle base with time.First flush needles had longer portions with YNC than second flush needles did.Needles from the lower crown also had more symptoms along their length than those higher in the canopy.Symptoms were similar to those reported for Mg.In chlorotic portions,Mg and Ca concentrations were well below critical values;in particular,Mg levels were only one third of the critical value of 0.3 g kg^(-1).Collectively,results suggest that Mg deficiency is the primary reason for NC of P.taeda in various parent soils in Brazil.

Genotype-environment interaction in Cordia trichotoma(Vell.)Arráb.Ex Steud.progenies in two different soil conditions

Investment in silvicultural techniques is noticeably lacking,especially in breeding programs for non-conventional wood species.Studying genotype×environment interaction(G×E)is essential to the development of breeding programs.Thus,this study aimed to estimate genetic diversity of and the effects of G×E interaction on two progeny tests of Cordia trichotoma,including the estimation of genetic gain and genetic diversity after selection.For the experiment,30 progenies of C.trichotoma were tested at two sites with differing soil textures.Diameter at breast height(1.30 m above soil surface,dbh-cm),total height,diameter at 30 cm from the soil,first branch height,and survival were all monitored for four years.Statistical deviance,best linear unbiased estimator,and harmonic mean of relative performance of genetic values(MHPRVG)were all calculated to predict breeding values,estimate genetic parameters,and analyze deviance.All quantified traits varied significantly among progenies by soil type,with greatest variation recorded for genetic variability.Heritability of the progenies led to predictions of genetic gain,ranging from 7.73 to 15.45%,for dbh at four years of age.The calculated decrease in genetic diversity after selection showed that this parameter should be monitored in subsequent breeding cycles.G×E was low for all tests.The best-performing progenies proved most stable and best adapted to the different environmental conditions tested.

Income Diversification through a Crop-Livestock-Forest Integration System in the Midwest Brazilian Region

Sustainability on farms is a challenge to competitiveness in the globalized market. In this scenario, due to the strong environmental, economic and social appeal, crop-livestock-forest integration systems have been considered as the future of agriculture. Regarding the economic approach, this system is based on the diversification of income generating activities, with revenue entry at different times, rationalization of resource use and reduction of risk of financial losses. Thus, the purpose of this work was to carry out the economic analysis of a crop-livestock-forest integration system, located at Boa Vereda＇s farm, in the municipality of Cachoeira Dourada in the state of Goi^is in the central-west region of Brazil. The system was composed of the following traditional crops of the region： soybean, corn, pasture, beef cattle and eucalyptus. The technical coefficients and the prices used for economic evaluation were obtained from the experimental unit and from the local market when crops were harvested in 2016/2017. The economic indicators used to assess economic viability were the net present value （NPV） and the equivalent annual uniform value （EAUV）. The results showed a return greater than the opportunity cost of the land, showing the attractiveness of the crop-livestock-forest integration system. Thus, this system represents an economically viable alternative that, among other benefits, allows the diversification of its sources of income, with a reduction of risk.

Soil Invertebrates in Different Land Use Systems： How Integrated Production Systems and Seasonality Affect Soil Mesofauna Communities

The soil mesofauna plays a role in organic matter comminution and decomposition, and can be used as bioindicators, since they are sensitive to soil management, vegetation and climate changes. Hence, this study aimed to evaluate mesofauna density and diversity in different land use systems to identify faunal relationships with soil properties, management and seasonality. The study area included five land use systems in Ponta Grossa municipality, Parana State： integrated crop-livestock （ICL）, integrated crop-livestock-forestry （ICLF）, grazed native pasture （NP）, Eucalyptus dunnii plantation （EU） and no-tillage （NT） cropping systems. In each system, eight soil samples for mesofauna were collected with Berlese funnels of 8 cm diameter along a transect in three replicate plots of 50 m × 100 m. For physical and chemical analysis, soil was sampled at five points per plot in two seasons： winter 2012 and autumn 2013. Data were statistically analyzed using ANOVA and Duncan＇s test （P 〈 0.05）, nonparametric statistics （when necessary） and redundancy analysis （RDA）. Diversity was calculated based on the group richness and Simpson index. The main mesofauna groups found were： Acarina, Collembola and Hymenoptera. Diplopoda, Enchytraeidae, Isopoda, Collembola, Hemiptera, Hymenoptera and Coleoptera larvae were more abundant in autumn than winter. Soil moisture was the main factor responsible for higher mesofauna abundance in autumn. Integrated production systems, especially ICLF had similar invertebrate community abundance and composition with EU, while NT favored Oribatid mites, although the use of insecticides, herbicides and fungicides reduced total mesofauna density. Most correlations between mesofauna and physical-chemical attributes in the winter were not observed in the autumn and vice versa, revealing that there are more factors involved in regulating soil mesofauna distribution.

Mixed-Species Allometric Equations to Quantify Stem Volume and Tree Biomass in Dry Afromontane Forest of Ethiopia

Volume and biomass equations are essential tools to determine forest productivity and enable forest managers to make informed decisions. However, volume and biomass estimation equations are scarce for Afromontane forests in Africa in general and Ethiopia in particular. This limits our knowledge of the standing volume of wood, biomass, and carbon stock of the forests therein. In this study, we developed a new mixed-species volume and biomass equations for Afromontane forests and compared them with generic pantropical and local models. A total of 193 sampled trees from seven dominant tree species were used to develop the equations. Various volume and biomass equations were fitted using robust linear and nonlinear regression. Model comparison indicated that the best model to estimate stem volume was ln(v)=-9.909+ 0.954*ln(d2h), whereas the best model to estimate biomass was ln(b)=-2.983+ 0.949*ln(ρd2h) . These equations explained over 85% of the variations in the stem volume and biomass measurements. The mean density and basal area of trees in the forest with d ≥ 2 cm was 631.5 stems·ha-1 and 24.4 m2·ha-1. Based on the newly developed equations, the forest has on average 303.0 m3·ha-1 standing volume of wood and 283.8 Mg·ha-1 biomass stock. The newly developed allometric equations derived from this study can be used to accurately determine the stem volume, biomass, and carbon storage in the Afromontane forests in Ethiopia and elsewhere with similar stand characteristics and ecological conditions. By contrast, the generic pan-tropical and other local models appear to provide biased estimates and are not suitable for dry Afromontane forests in Ethiopia. The estimated stem biomass and carbon stock in the Chilimo forest are comparable with the estimates from various tropical forests and woodlands elsewhere in Africa, indicating the importance of dry Afromontane forest for climate change mitigation.

Using dung beetles to evaluate the effects of urbanization on Atlantic Forest biodiversity

We used dung beetles to evaluate the impact of urbanization on insect biodi- versity in three Atlantic Forest fragments in Londrina, Parana, Brazil. This study provides the first empirical evidence of the impact of urbanization on richness, abundance, compo- sition and guild structure of dung beetle communities from the Brazilian Atlantic Forest. We evaluated the community aspects （abundance, richness, composition and food guilds） of dung beetles in fragments with different degrees of immersion in the urban matrix using pitfall traps with four alternative baits （rotten meat, rotten fish, pig dung and decaying ba- nana）. A total of 1 719 individuals were collected, belonging to 29 species from 11 genera and six Scarabaeinae tribes. The most urban-immersed fragment showed a higher species dominance and the beetle community captured on dung presented the greatest evenness. The beetle communities were distinct with respect to the fragments and feeding habits. Except for the dung beetle assemblage in the most urbanized forest fragment, all others exhibited contrasting differences in species composition attracted to each bait type. Our results clearly show that the degree of urbanization affects Atlantic Forest dung beetle communities and that the preservation of forest fragments inside the cities, even small ones, can provide refuges for Scarabaeinae.

Assessment of food supplementation and surveillance as techniques to reduce damage caused by black capuchin monkeys Sapajus nigritus to forest plantations

Black capuchin monkeys Sapajus nigritus are among several mammalian species that damage forest plantations, pri- marily plantations of pine trees （Pinus spp.） in South Brazil. Management practices to reduce these damages include supplemen- tary food offerings and plantation surveillance. To assess the efficiency of these techniques, four treatments were evaluated： feeding （F, with supplementary bananas and maize）, surveillance （S, in situ, wherein men patrolled the plantations, deterring the monkeys）, feeding ＋ surveillance （FS） and control （no procedures） （C）. The efficiency assessment of each treatment involved the number of recorded primate sightings in the treatments with the presence of guards （S and FS） and a damage inventory of the outskirts of the experimental points immediately before and after the experiment. These data were complemented by a simulta- neous study of the availability of fruit, the primary item in the diet of this primate species, in the remnant native forest in the study area. Most sightings of S. nigritus occurred early in the morning, and in general, sightings were inversely proportional to the availability of native fruits. This trend was most evident in treatment FS, most likely due to the presence of food. Treatments F and FS exhibited higher percentages of damage, indicating that these are inefficient management techniques. Treatment S exhi- bited the lowest damage rate, but at a high cost, making this technique difficult to apply over large expanses. The development of other management techniques, such as environmental enrichment and the use of deterrents, is recommended to minimize the damage caused by capuchins in forest plantations [Current Zoology 60 （5）： 581-590, 2014].