Growth Response to Weed Control and Fertilisation in Mid-Rotation Plantations of Eucalyptus pellita in South Sumatra, Indonesia

We report on a study of mid-rotation weed control and nutrient management in Eucalyptus pellita plantations in South Sumatra. The study was established at two contrasting sites (representing high and low productivity for the region) that had previously carried three rotations of Acacia mangium. A combination of weed control, nitrogen (N), and phosphorus (P) fertiliser were applied at 1 and 2 years after establishment. We found that the addition of up to 250 kg N ha−1 applied either at 1 year or 2 years after planting did not improve growth. The application of P (30 kg P ha−1) at age 1 year (in addition to 12 kg P ha−1 applied at planting) did not enhance tree growth either. Keeping the plantation free from weed competition throughout rotation (full weed control) enhanced wood volume up to age 4 years at the high-productivity site, while it improved wood volume up to the end of rotation at age 6 years at the low-productivity site. An additional experiment assessing the effect of weed control in the early phase of plantation establishment revealed that weed competition reduced young tree growth of E. pellita substantially. The results of the studies support the current practice of plantation management of E. pellita in the region that applied only P fertiliser at planting time and that kept trees free from weed competition before canopy closure. Full weed control throughout rotation is worth practicing at lower-productivity sites to achieve maximum productivity.

Individual Protective Covers (IPCs) for Young Tree Protection from the HLB Vector, the Asian Citrus Psyllid

Psyllid exclusion is the most effective strategy to keep citrus trees free from HLB. Individual protective covers (IPCs) are a novel strategy based on psyllid exclusion of individual trees using a protective mesh bag. This new 3-page publication summarizes the knowledge we have accrued from our 3-year-long field studies using the IPC system and provides recommendations that can help with effective use of this technology. By F. Alferez, U. Albrecht, S. Gaire, O. Batuman, J. Qureshi, and M. Zekri.https://edis.ifas.ufl.edu/hs1425

ESPACE BOISE DE LECOFERME DE LOKOLI (SINEMATIALI, NORD DE LA COTE DIVOIRE) : UN CAS DE COMPENSATION ECOLOGIQUE

When ecosystems are well managed, they are carbon sinks. The objective of this study is to know the state of the plant biodiversity of the wooded area of the Lokoli Ecofarm and its contribution to the regulation of the climatic regime, with a view to better conservation decision-making.A floristic inventory made it possible to determine the diversity and the floristic composition of the ligneous plants in the different Ecofarm habitats. Dendrometric measurements were carried out to determine the structural profile and the sequestered carbon stock of each habitat. The floristic study made it possible to identify 63 woody species divided into 251 classified into 22 families. The open forest has proven to be the richest in species and the most diverse. The structure in diameter classes reveals that the different biotopes are dominated by young tree stems, with a strong tendency to regenerate. The amount of carbon contained in the total biomass was found to be greater in the fallow (8.87 t / ha) than in the open forest (6.53 t / ha) and savannah (6.88 t / ha). The sequestered atmospheric carbon is estimated at 108.98 t / ha in total, for an economic value varying from 27,799.34 to 124,279.41 euros depending on the different carbon markets. In addition, this study showed that fallow significantly contributes to increasing the carbon sequestration potential of the Ecofarm.

The Relationship Between Social Support Of Coolers And The Self Adjustment Of Employees With The Deaf

This research was conducted because there is a phenomenon of adjustment problems for deaf employees in their workplace, PT. Young Tree Industry Sidoarjo. The purpose of this study was to determine the relationship between the social support of coworkers and the adjustment of deaf employees at PT. Young Tree Industry Sidoarjo. This research is a correlational quantitative research. The population of deaf employees is 23 people so that all of them are used as research samples. The data collection technique uses a psychological adjustment scale and social support which is arranged on a Likert scale. The data analysis technique for hypothesis testing was carried out with the Pearson Correlaton Product Moment. The results of this study indicate the correlation coefficient (rxy) = 0.834 (significance 0.000 <0.05). Thus the research hypothesis is accepted, that there is a positive relationship between co-workers' social support and adjustment to deaf employees at PT. Young Tree Sidoarjo. This means that the higher the social support, the higher the adjustment, and vice versa. The determination test shows the effect of social support on self-adjustment by 68%.

Tree diversity effects on forest productivity: disentangling the effects of tree species addition vs. substitution

Mixture effect on stand productivity is usually apprehended through a substitutive approach, whereby productivity in mixed stands is compared to productivity in monocultures, at equivalent stand density. This approach has proved that in many cases mixed stands perform better than monospecific forests, however, we do not yet have a solid theory about species behaviour in the mixture or even guidelines for combining species. The addition of a second tree species to an existing mono-specific stand has received much less consideration. Yet, this approach has the potential to separate the facilitation effect from the complementarity effect. We compared the effect of tree species substitution vs. addition on the productivity of maritime pine and silver birch in a young tree diversity experiment implemented in 2008 in SW France. Substituting pines with birches to create two-species mixtures resulted in an increase of tree productivity at stand level beyond what was expected from monocultures (i.e., overyielding). In contrast, creating mixture through the addition of birches to pine stands had no effect on the maritime pine stand productivity (transgressive mixture effect not significant). This absence of effect is produced by two distinct density-dependence responses at an individual level. Our results allow clarifying the cases in which a mixed stand can be considered as an alternative to a monoculture of a productive species. In particular, the addition of a pioneer and soil low-demanding species during young developmental stages is a possibility to diversify the stand and potentially to increase ecosystem services without altering the productivity of the target species.

KEANEKARAGAMAN JENIS VEGETASI PAKAN BADAK FASE SEMAI DI ZONA KHUSUS KONSERVASI TAMAN NASIONAL WAY KAMBAS

The Sumatran rhinos (Dicerorhinus sumatrensis) is the smallest of the five species of rhinoceros that still alive. Way Kambas National Park (TNWK) is captivity semi-insitu of Dicerorhinus sumatrensis. The Sumatran rhinos are herbivorous with a preference of young tree (seedling), leaves, fruits, and shoots.The importance of knowledge about study of feed sumatran rhinos for conservationof rhino in TNWK. The purpose of the study is to identifies rhino feed on seedling growth level in the conservation zones TNWK. The research used line transect method. The first line and plot determined randomly then the next line and plots was sistematically. The observation plots had measurement with amount 2m x 2m of seedling growth level in big plot with amount 20m x 20m with spacing between plot in line 500 m with total 98 plots. The results of this study concluded that there were 28 types of seedling rhino feed which was found to be the most abundant and evenly distributed based on the important value index, are Ixora sp. is 16.73 and then Antidesma neurocarpum Miq is 14.4 and Dillenia excelsa is 10.89. Biodiversity index is 3.57 and evennes index is 0.84.

Optimizing Irrigation and Young Tree Management

Young citrus trees require optimal irrigation management for vigorous vegetative growth, leaf flushing, and establishment of a dense canopy. Poor irrigation practices, such as infrequent irrigation or irrigating without using irrigation scheduling tools, could be costly. Besides excessive loss of water and nutrients, the growth of young trees might be impacted by an excess or deficit of water. Crop water stress in young trees directly affects yield and fruit quality. This new 2-page publication of the UF/IFAS Department of Soil and Water Sciences, written by Davie Kadyampakeni and Sandra Guzmán, covers some strategies for optimizing young tree care and irrigation management to in turn optimize grove efficiency and productivity.https://edis.ifas.ufl.edu/ss701

Long time risk assessment of soil water shortage in planting pits of young urban roadside trees in the city of Hamburg, Germany

&lt;p&gt;Urban trees as main part of urban green infrastructure provide manifold ecosystem services and contribute to the wellbeing of humans. Unfortunately, urban trees, especially roadside trees, are severely challenged by both, political conflicts of interests in terms of city development and a variety of physically stressors. Contrary to the known benefits of urban green, its proportion in most cities is still decreasing. Furthermore, climate change exacerbates the already challenging preconditions.&lt;/p&gt;&lt;p&gt;For northern Germany, climate change is predicted to shift temperature- and precipitation patterns. Simultaneously the frequency of &amp;#8220;summer days&amp;#8221; and &amp;#8220;hot days&amp;#8221; are likely to increase, leading to elevated risk of soil drying during the vegetation period.&lt;/p&gt;&lt;p&gt;The city of Hamburg is home to almost 220.000 roadside trees. Especially trees planted nowadays are exposed to harsh roadside conditions. In the event of drought, young-trees compared to well-established trees, are not in touch with deep- or distant water reservoirs and the risk of vitality loss or death increases.&lt;/p&gt;&lt;p&gt;Our research aims to characterize the soil hydrological conditions in the rooting zone of roadside young-trees during the first years after plantation. Further it aims to identify spatio-temporal dynamics of soil water response during phases of extreme meteorological drought. Our findings are based on a long-term soil water monitoring across the city of Hamburg, which was started in 2016. The monitoring covers 20 trees from 7 species, planted between 2007 and 2019 with large, medium and low soil sealing. Soil water tension and soil temperature were measured hourly with sensors in the root ball, in the tree pit filled with structural soil and the surrounding soil (16 sensors per site).&lt;/p&gt;&lt;p&gt;Our data provides a broad characterization of soil water conditions for young-tree sites in urban areas, and show that water supply in years of moderate meteorological drought is not only extremely heterogeneous on large scales, but can also vary greatly on a small scale. The water tension in the root ball, which should provide the highest amount of water per unit, was highly variable and exceeded thresholds even in the first year after plantation and in almost every vegetation period across all sites. In years of high meteorological drought like in 2018, the soil water tensions exceeded the thresholds in almost all compartments, which leads to a risk of vitality losses and mortality.&lt;/p&gt;&lt;p&gt;Our data show the need for adaption of general tree site concepts for future plantations. This unique dataset will be further completed with the aim to include future sites and plantation strategies e.g. the underground connection of planting pits, to increase the diversity of site characteristics and to develop reliable modelling and recommendations.&lt;/p&gt;