Conservation Plots Research Articles

The role of conservation agriculture in enhancing biodiversity and common beans productivity

Conservation of biodiversity in agricultural landscapes is vital for maintaining ecosystem stability and resilience. Conservation agriculture, a sustainable farming approach that involves minimum tillage and reduced use of synthetic pesticides, herbicides, and growth promoters, has gained attention as a potential strategy to enhance biodiversity and reduce production costs. This study investigated the role of conservation agriculture in enhancing biodiversity and common bean productivity in Tanzania. The study compared plots practicing conservation agriculture (minimum tillage and reduced agrochemical use) with those using conventional farming methods. Biodiversity metrics, that is, earthworm populations, bird species richness, bird nest abundance, bird species diversity, bee visitation rates, and bean yield were assessed. The results showed significant positive effects of conservation agriculture on biodiversity, emphasizing its potential role in promoting sustainable agriculture, biodiversity conservation, and household improvement due to reduced production costs and increased yield per unit area. Earthworms per meter square observed to increase from 12 in the non-conservation plots to 34 in the conservation plots, which is likely to improve nutrient cycling and productivity. Furthermore, conservation plots had a higher number of bird species flying around (36−76) compared with 14–32 in non-conservation plots (4000 m2) at 50 % bean flowering. The number of bird nests observed in the two plots during bean harvesting varied significantly (P<0.05), where the number of bird nests observed in 4000 m2 of non-conservation plots ranged from 14 to 36, compared to 12–62 in conservation plots. High bird nest numbers in conservation plots indicated higher bird habitat quality in conservation plots than in non-conservation plots. Bees as chief pollinators, bees visiting conservation plots during 50 % flowering per square meter ranged from 5 to 11, compared to 2–6 in non-conservation plots. Bee visitation to bean flowers has a significant influence on productivity, as it influences pollen transfer and fertilization. Common beans yield among plots ranged 0.9 tons/ha to 1.4 tons/ha in conservation plots compared to 0.35–1.01 tons/ha, in non-conservation plots. Land use conservation contributes considerably to economic growth through increased productivity and reduced production costs, where the production cost is reduced by 50 % in conservation plots compared with non-conservation plots. However, the present study was conducted in a single location with smallholder farmers; hence, further experiments over larger areas and longer time periods are needed for a more robust conclusion.

Population, morphological, and genetic characteristics of pelawan trees on Bangka Island, Indonesia: implications for conservation

Tristaniopsis spp. (pelawan) trees hold great significance in ensuring biodiversity sustainability and supporting the local species within Kepulauan Bangka Belitung Province. Moreover, it plays a crucial role in fostering the social and cultural aspects of the local community. However, the pelawan population has faced great threats due to land conversion, unmanaged forests, and mining. To address these challenges, the local government has shown a commitment to expanding the in-situ conservation areas beyond Namang Biodiversity Park. In order to enhance the conservation status of this species, it is essential to conduct a comprehensive study of the tree’s distribution, morphological characteristics, species delimitation, and genetic diversity. Therefore, this study aimed to obtain information on pelawan distribution, morphological characteristics, species confirmation, and genetic diversity. It was conducted at five natural populations, namely KK (Kota Kapur), BB (Berbura), LAP (Labuh Air Pandan), PN (Pangkal Niur), and LB (Limbung), and the genetic character was observed using ITS and RAPD markers. The first instance of establishing a nucleotide sequence database for pelawan on Bangka Island was also represented, showing the presence of two distinct taxa groups based on ITS sequence nucleotides. Based on morphological characters (bark color and leaves), the two groups were determined to be pelawan merah/orange (Tristaniopsis sp. 1) and pelawan air (Tristaniopsis sp. 2). Significantly, the genetic diversity analysis yielded a range of HE values, from 0.283 (KK) to 0.353 (PN). The PCoA and dendrogram analyses exhibited the formation of a cluster comprising populations from Bangka (KK, BB, LAP, and PN), while LB formed a separate cluster. The result showed significant genetic differentiation between regions and populations, without mixing seeds or seedlings. It was suggested that the conservation strategy for pelawan trees on Bangka Island should be developed with several considerations. In-situ conservation sites should be designated based on the presence of pelawan merah/orange and pelawan air taxa. Additionally, ex-situ conservation plots needed to be established, with at least one location dedicated to each taxonomic group. To preserve the remaining natural genetic resources, KK and LB populations, which had the lowest HE value and different genetic structures should be prioritized. Strategies for ex-situ conservation included KK, LB, and PN. The prioritization of PN for conservation was necessary, and further genetic study of the pelawan should involve larger populations representing the natural distribution of each species.

Genetic diversity of Pericopsis mooniana from South Kalimantan based on Random Amplified Polymorphism DNA (RAPD) Markers

The genetic diversity and relationship of Pericopsis mooniana collected from Pulau Laut, South Kalimantan, was analyzed using RAPD markers. Currently, the natural distribution of P. mooniana in Pulau Laut no longer exists. Instead, PT Inhutani II, as the concession holder in the area, had collected the remaining P.mooniana and planted it in the seed orchard, arboretum, or around PT Inhutani’s mess/office. Forty-two samples from four locations: mess/residential house (3), seed orchard (33), arboretum (3), and PT Inhutani II Unit Stagen (3) were analyzed using seven RAPD primers. Our study showed that the total genetic diversity of all populations was low (He = 0.191 ± 0.013). P. mooniana collected from seed orchards had the highest diversity (He = 0.289 ± 0.021), while the lowest was from mess/residential houses (He = 0.134 ± 0.025). The genetic relationship data indicated the possibility that P. mooniana from mess/residential house, arboretum, and seed orchard may come from the same origin. These results can be used to support the development of ex-situ conservation plots to avoid inbreeding depression. At the same time, the genetic diversity will be helpful in its conservation and further utilization, such as establishing the plantations to reduce the pressure of the species in nature and provide valuable timber production in Indonesia.

Pertumbuhan Ulin (Eusideroxylon zwageri Teijsm &amp; Binn.) dari Beberapa Provenans Di KHDTK Samboja, Kalimantan Timur

The high conservation status of ironwood (Eusideroxylon zwageri Teijsm &amp; Binn.) causes conservation efforts need to be carried out immediately. Balitek KSDA has carried out ulin conservation efforts by building ulin ex-situ conservation plots in the Samboja KHDTK with seeds from the Sungai Wain, Sangatta and Berau. This study was conducted to evaluate the variation of ironwood plant growth from these three provenances in the Samboja KHDTK. The results showed that the average survival rate of ironwood plant was 79.12% and there were no differences in the three provenances. Plants from Sangatta have the best height and diameter growth compared to the Sungai Wain and Berau, which is 83.48 cm and 0.61 cm.

Effect of tillage and irrigation on Southeastern U.S. soils under cellulosic sorghum feedstock production

ABSTRACT Sorghum may be a good cellulosic material for bioenergy production because it can be cultivated in current row-crop systems. However, the production of sorghum for bioenergy and its impacts on Southeastern U.S. soils should be investigated to determine the most environmentally sustainable system. The objective of this study was to evaluate tillage (conventional vs. conservation systems), and irrigation effect (irrigated vs. non-irrigated) on soil characteristics when producing cellulosic feedstock from three forage sorghums and one forage corn (control) in 2008 and 2009. Results showed that soil organic carbon (SOC) increased at a depth of 0.10–0.15 m, but decreased at a depth of 0.40–0.45 m with higher losses being found using conventional tillage as opposed to conservation tillage. Total nitrogen (TN) and bulk density (Bd) increased at all evaluated soil depths (0–0.50 m) after 2 years. Conventional tillage plots also showed higher Bd at 0.15–0.30 m. Higher Bd in conventional tillage plots might restrict water drainage which could explain higher volumetric soil water content (SWC) at 0.10, 0.20 and 0.40 m soil depths. Cone Index (CI) values also showed improved soil conditions at in-row positions for conservation plots.

Slug Monitoring and Impacts on the Ground Beetle Community in the Frame of Sustainable Pest Control in Conventional and Conservation Agroecosystems.

In conservation agriculture, slugs are considered significant pests and their monitoring is a key option in the integrated pest management framework. Together with molluscicide applications, predators such as ground beetles can offer a tool for slug control in the field. Through the evaluation of slug and ground beetle monitoring strategies, this work compared their presence in conventional and conservation agricultural plots. The invasive Deroceras invadens was the dominant slug species to occur in all sampling periods. Among Carabidae, Poecilus cupreus and Pterostichus melas were the most abundant species, and Bembidion spp., Brachinus spp., and Harpalus spp. were also common. Beer-baited pitfall traps, whatever their alcoholic content, caught more slugs and ground beetles than wooden boards used as shelters. Slugs were more abundant in conventional plots than in conservation plots, possibly due to the lower presence of natural enemies such as ground beetles. Despite possible impacts on Carabidae, beer-baited pitfall traps should be considered a useful tool for slug monitoring and for the planning of molluscicide applications. Soil management such as minimum- or no-tillage and the presence of cover crops are important elements influencing both slug and ground beetle presence, possibly playing a key role in the maintenance of natural enemy populations.

Genetic diversity of Shorea producing tengkawang populations in Kalimantan based on SSR markers

Shorea producing tengkawang grows naturally in Indonesia, however several species are now listed in the IUCN as endangered species. Their presences in natural forests arebecoming scarce so that it requires conservation efforts such as the construction of ex- situ conservation plots. This research aims to obtain data and information about the genetic diversity structure of several species of Shorea producing tengkawang. The material used was leaf samples from 11 (eleven) populations consisting of 4 (four) species of Shorea producing tengkawang. The method used 4 pairs of microsatellite DNA markers (SSR), and data analysis used POPGENE and GenAleX. The results show various genetic distances between populations, ranging from 0.028 to 1.510 with the value of genetic diversity in the population larger (72%) than among the populations (28%). Genetic diversity in the population ranges from 0.5269 - 0.8244. Cluster analysis shows that the existing Shorea producing Tengkawang population does not form a specific grouping. This genetic diversity information can be used as the basic data for the development of Shorea producing tengkawang ex-situ conservation plots.

Evaluation of five seeds of medicinal plants in the nursery level

Five plants i.e.Kemuning (Murrayapaniculata (L.) Jack), Temurui (Murrayakoenigii (L.) Spreng), Kuntobimo (Kigeliaafricana (Lam.) Benth. Syn. K. pinnata (Jacq.) DC.),Sala (CouroupitaguianensisAubl), and Salam (Syzygiumpolyanthum (Wight) Walp.) are regarded as types of plants that have the potential to be developed as raw materials for herbal medicine. Those five plants were planted in thespecies trial as well as ex-situ conservation plots in the Grand Forest Park Bunder, Gunungkidul at the end of 2018. This study aimsto find out more about research status of these plant types by literature review method, e.g. from books, proceedings, both print and online journals, and conducting seed evaluation in the Yogyakarta Center for Forest Biotechnology and Tree Improvement. Seed evaluation method in the nursery was conducted by measuring diameter, height and sturdiness of as many as 36 seedlings for each plant. The seed evaluation in the nursery showed the average diameter of 4.93 mm, theaverage height of 31.66 cm, and the average seedling sturdiness of 6.63. The evaluation results also show that the best seeds ready for field test planting in order are Sala, Salam, and Kemuning. As for Temurui and Kuntobimo seedlings, due to their limited height, an intensive maintenance is needed, especially fertilization, so that at the end of the year theywould also beready for field planting.

Blanket peat erosion: Theoretical considerations and observations from selected conservation sites in Slieveanorra Forest National Nature Reserve, County Antrim

Geomorphological investigation of blanket peat at three conservation plots in Slieveanorra Forest National Nature Reserve, County Antrim, suggests that various stages of peat erosion are concurrent. The proximity of undisturbed peat, gullies and haggs, peat flats, redistributed peat and regenerated peat is described. Morphological evidence may be interpreted in terms of a natural cycle or system of peat erosion but pollen analysis suggests a linkage between agricultural activity and the commencement of erosion. A C14 date of 2108 BP implies a much earlier date for peat erosion than generally considered. Erosion processes and origins are discussed and related to theories of upland blanket peat erosion.

Conservation Horticulture in Mango Orchards: Comparative Effects of Conventional and Conservation Management Practices on Soil Properties of an Alfisol under Seasonally Dry Tropical Savanna Climate

&lt;p&gt;Conservation horticulture is a new concept in management of soil health under perennial horticultural cropping systems. Experiments conducted reasonably over a long period on such soil management systems provide valuable information about sustainability of production systems. This paper reports the results of comprehensive investigations on soil chemical, physical, biochemical and biological properties of soils under conventional and conservation horticulture practices over a long period in drylnd mango orchards on Alfisols. Effects of conservation tillage, inter cropping and cover cropping on soil carbon fractions was measured by determination of loss on ignition, organic carbon (OC) and active carbon (AC). Soil biochemical properties were evaluated by measuring glomalin and extracellular enzymatic activities viz., dehydrogenase, urease, phosphomonoestrase and arylsulphatase and measurement of soil microbial biomass carbon (MBC) and carbon mineralization. Biological status was evaluated by estimating bacterial, actinobacterial and fungal populations, earthworms, micro arthropods and centipedes. Soil physical status was assessed by measuring bulk density, soil moisture status and infiltration rates.&lt;/p&gt;&lt;p&gt;Conservation horticultural practices improved the quality of soil, especially near the surface, by lowering the bulk density and enhancing infiltration rate. The soil aggregate formation and water stability have enhanced in plots with conservation practices because of higher production of glomalin compared with vegetable and orchard plots where conventional practices were followed. Relationship between measured infiltration and soil properties showed high average IRs in conservation plots due to high organic matter content, low bulk density values and enhanced exchangeable basic cations. Vegetable plots and conventional mango plots showed complete decline in earthworm and centipede population while plots with conservation practices showed a build-up of their population. Microbial and biochemical properties significantly improved in plots with conservation horticultural practices over orchard plots with conventional practices. Legumes as inter and cover crops were found to be superior in improving soil quality than sweet potato.&lt;/p&gt;

Plastic Responses Mediated by Identity Recognition in Below-Ground Competition in Cycas micronesica K.D. Hill

We studied the ability of Cycas micronesica roots to recognize the identity of competitor roots using pot culture. Pairs of seedlings were grown in single pots for 10.5 months, and morphological traits of the focal plant were determined when the non-focal plant was a half-sibling, a close relative from a mother 170 m away, a distant relative from a habitat 40 km away, or a different species ( Cycas edentata) from Mindanao, Philippines. Most of the measured response traits exhibited similar trends and confirmed that C. micronesica plant roots were able to recognize the identity of competitors. For example, focal plants grown in pots with C. edentata competitors exhibited 66% increase in fine root dry weight, 54% increase in coralloid root dry weight, and 49% increase in total plant dry weight, compared to focal plants grown in competition with half-siblings. Our methods have shown that plot design in ex situ conservation and botanic garden settings would improve by positioning C. micronesica plants adjacent to non-relatives. Recruitment may improve within in situ conservation plots if managers distribute seeds away from the maternal parent so that emerging seedlings are not forced into immediate competition with half-siblings. These findings may be useful for designing more complex experiments to quantify the influence of these plastic root responses on plant nutrient status and physiology.

Topographic Relief, Wind Direction, and Conservation Management Decisions Influence Cycas micronesica K.D. Hill Population Damage during Tropical Cyclone

Typhoon Dolphin damaged forest resources in northern Guam on 15 May 2015, and we assessed the responses of the native tree Cycas micronesica to the destructive winds. We compared the damage to that of previous typhoons, evaluated topographic traits that affected tree damage, and assessed the influence of prior management decisions for in situ conservation plots on damage. Snapping of stems near the ground was greater in this typhoon than in past typhoons, confirming predictions that chronic infestations of non-native insect herbivores compromised the biomechanical integrity of stem tissue. Tree failure as snapping of stems or uprooting/toppling increased from 1% to 23% along an elevation gradient that faced windward, indicating orographic lifting increased wind force and mediated the tree response. Two years of conservation management within in situ plots reduced tree damage and saved up to 16% of the population, depending on site. Case studies such as this one are needed to more fully understand future impacts of increased frequency of intense TCs that are predicted with climate change models.

Effectiveness of Conservation Measures in Reducing Runoff and Soil Loss Under Different Magnitude-Frequency Storms at Plot and Catchment Scales in the Semi-arid Agricultural Landscape.

In this study, multi-year stormflow data collected at both catchment and plot scales on an event basis were used to evaluate the efficiency of conservation. At the catchment scale, soil loss from YDG, an agricultural catchment with no conservation measures, was compared with that from CZG, an agricultural catchment with an implementation of a range of conservation measures. With an increase of storm recurrence intervals in the order of <1, 1-2, 2-5, 5-10, 10-20, and >20years, the mean event sediment yield was 639, 1721, 5779, 15191, 19627, and 47924 t/km(2) in YDG, and was 244, 767, 3077, 4679, 8388, and 15868 t/km(2) in CZG, which represented a reduction effectiveness of 61.8, 55.4, 46.7, 69.2, 57.2, and 66.8%, respectively. Storm events with recurrence intervals greater than 2years contributed about two-thirds of the total runoff and sediment in both YDG and CZG catchments. At the plot scale, soil loss from one cultivated slopeland was compared with that from five conservation plots. The mean event soil loss was 1622 t/km(2) on the cultivated slopeland, in comparison to 27.7 t/km(2) on the woodland plot, 213 t/km(2) on the grassland plot, 467 t/km(2) on the alfalfa plot, 236 t/km(2) on the terraceland plot, and 642 t/km(2) on the earthbank plot. Soil loss per unit area from all the plots was significantly less than that from the catchments for storms of all categories of recurrence intervals.

Diversity of Ethnomedicinal Plants in Boridand Forest of District Korea, Chhattisgarh, India

Present study deals with an extensive ecological assessment of natural forest areas under several in-situ conservation plots which have resulted from high rate of grazing and biotic pressure. Over-exploitation of forest and unwanted incidental fire cases decreased the diversity of several ethnomedicinally and economically valuable plants species from the Boridand forest region in Korea district, Chhattisgarh. The total number of plants reported in all three study sites, 41 plants species belonging to 26 families and 37 plant genera were identified. A field survey was conducted at three different study sites in Boridand forest, district Korea, Chhattisgarh as Plot A, Plot B and Plot C, during months March 2013 to February 2014 to identify the diversity of ethnomedicinal plants.

KARAKTERISASI KERAGAMAN GENETIK POPULASI JABON PUTIH MENGGUNAKAN PENANDA RANDOM AMPLIFIED POLYMORPHISM DNA

Anthocepalus cadamba (white jabon) has high economical value for furniture. White jabon forests severely degraded due to intensive exploitation and land conversion. Genetic diversity is one of important consideration to design conservation and improvement strategies. Aim of this study was to access the genetic diversity values within and among population of white jabon. Leaf samples of white jabon were collected from conservation plots originated from West Lombok, Sumbawa, South Sumatera and West Sumatera. Red jabon was included as an outgroup population. Based on 37 polymorphic RAPD loci, the results showed comparable value of genetic diversity between white jabon and red jabon. Number of detected and rare alleles was highest founded in Sumbawa population among the other three populations of white jabon. As consequence, value of expected heterozygosity in the population was highest (HE=0.315). Private allele was only detected in South Sumatera population. Principal coordinate analysis (PCA) showed that integrating between genetic and geographical distance was inconsistent; similar gene resources or human impact might be responsible for this result. The populations that have high value of genetic diversity and private allele are recommended to be selected for the conservation strategies, i.e. Sumbawa and South Sumatera.

Assessment of soil erosion and conservation on agricultural sloping lands using plot data in the semi-arid hilly loess region of China

Abstract Study region Semi-arid hilly loess region of China. Study focus The objectives of this study were to investigate soil and water loss on agricultural sloping lands and to evaluate the effectiveness of soil conservation practices in controlling erosion using plot data. Runoff and soil loss were measured from the short slope plots (SSP) (7 m long) and the long slope plots (LSP) (20 m long) at various slope angles as well as from cropland and soil conservation plots (SCP) under natural rainfalls. New hydrological insights for the region The results revealed that runoff per unit area slightly increased with slope angle on SSP, but reached a maximum at 15° and then decreased with slope angle on LSP. Soil loss per unit area increased with slope angle on both SSP and LSP. An average of 36.4% less runoff but only 3.6% less soil loss per unit area was produced on LSP than on SSP. The S factor calculated using the slope factor equations in USLE/RUSLE was significantly greater than that estimated from the measured soil loss on the plots. Rainstorms with recurrence intervals greater than 2 years were responsible for more than two thirds of the total soil and water loss. The effectiveness in reducing surface runoff by five types of conservation practices was mixed. However, all the conservation practices yielded much less soil loss than cropland.

Management of apple orchards to conserve generalist phytoseiid mites suppresses two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae)

To improve the success of integrated pest management (IPM) in apple orchards, we investigated whether generalist phytoseiid mites have suppressed the occurrence of Tetranychus urticae. In Akita Prefecture, northern Japan, in 2012 and 2013, two types of experimental plot were compared. Conservation plots had been managed for the conservation of generalist phytoseiid mites by selective chemical spraying without mowing since 2009. Conventional plots were managed by non-selective chemical spraying with regular mowing. The conservation plots had significantly fewer T. urticae adult females per tree in both years. Two species of generalist phytoseiid mites-Typhlodromus vulgaris and Amblyseius tsugawai-were continuously present in the conservation plots, with only a few T. urticae. The conservation plots had significantly more A. tsugawai adult females in the undergrowth in both years, and significantly more T. vulgaris adult females on apple leaves in 2012. Typhlodromus vulgaris was continuously present in the conservation plots but was scarce from late May to early August in the conventional plots. In the presence of T. vulgaris, low numbers of T. urticae did not increase on apple leaves. These results indicate that the generalist phytoseiid mites serve as important biological control agents in IPM in apple orchards.

ADAPTABILITAS, PERTUMBUHAN DAN REGENERASI PADA PLOT KONSERVASI EX SITU MERBAU

Merbau is one of threatened forest genetic resources. Based on IUCN Red List Categories. conservation status of merbau is vulnerable (VU A1cd). Conservation effort of merbau is urgently required to save this species from extinction. Center for Forest Biotechnology and Tree Improvement Yogyakarta had established ex situ conservation plots of merbau in Forest Research in Bondowoso, East Java and Gunung Kidul Yogyakarta. Genetic resources used in those ex situ conservation plots were from seven provenances namely Halmahera Timur, Waigo, Oransbari, Wasior, Nabire, Seram, dan Mandopi/Twanwawi. This research aims to evaluate adaptability, growth and regeneration of merbau plants grown in ex situ conservation plots in Bondowoso dan Gunung Kidul. The ex situ conservation plot in Bondowoso was designed as Randomized Complete Block Design with single factor of provenance. At the ex situ conservation plot in Gunung Kidul each provenance was planted in one block. The results showed that adaptability of merbau plants at ex situ conservation plots in Bondowoso dan Gunung Kidul was good. Growth of height and diameter of merbau plants from several provenances at ex situ conservation plot in Gunung Kidul were better than those in Bondowoso at all observation ages. Height and diameter average of merbau plants at ex situ conservation plots in Bondowoso and Gunung Kidul at one year old were 78.21 cm; 9.58 mm and 97.88 cm; 9.58 mm respectively. Height and diameter average of merbau plants at ex situ conservation plots in Bondowoso and Gunung Kidul at two years old were 95.36 cm; 12.95 mm and cm; 19.62 mm respectively . Regeneration of merbau has been successful at Gunung Kidul plot. Some of the fallen seeds were then grown to be wildlings. Whereas, regeneration of merbau at ex situ conservation plot in Bondowoso was regarded as not successful

ISSR markers for analysis of molecular diversity and genetic structure of Indian teak (Tectona grandis L.f.) populations

Inter simple sequence repeats (ISSR) constitute a powerful domi- nant DNA molecular marker system used for diversity analysis, which is indispensable for making estimates of genetic base and demarcation of pop- ulations for undertaking conservation and improvement program of forest tree species. Twenty nine populations of teak (Tectona grandis L.f.) were collected from central and peninsular India for analysis of genetic diver- sity and structure. Genomic DNA from ten randomly selected individuals of each population was extracted and amplified using five ISSR primers (UBC-801, 834, 880, 899 and 900). The primers showed 100% polymor- phism. UBC-900 recorded the highest Nei's genetic diversity (0.32 to 0.40) and UBC-899 had the highest Shannon's Information Index (0.49 to 0.59). AMOVA revealed a very high intra-population genetic diversity (91%), in comparison to inter-population genetic diversity among states (6.17%) and within states (2.77%) which were also indirectly confirmed by large stand- ard deviations associated with genetic diversity estimates for individual population, as well as poor bootstrapping values for most of the cluster nodes. However, UPGMA dendrogram revealed several clusters, with pop- ulations from central India being present almost in each cluster, making groups with populations of adjoining states and distant states. Neverthe- less, the cluster analysis distinguished the drier teak populations of cen- tral India from the moist teak populations of south India, which was also confirmed by Principle Coordinate Analysis. The findings advocates the need not only for enhancing selection intensity for large number of plus trees, but also for laying out more number of in situ conservation plots within natural populations of each cluster for germplasm conservation of teak aimed at improving the teak productivity and quality in future. Keywords Tectona grandis, teak, genetic diversity, population differentiation.

Effect of Tillage and Planting Date on Seasonal Abundance and Diversity of Predacious Ground Beetles in Cotton

A 2-year field study was conducted in the southern High Plains region of Texas to evaluate the effect of tillage system and cotton planting date window on seasonal abundance and activity patterns of predacious ground beetles. The experiment was deployed in a split-plot randomized block design with tillage as the main-plot factor and planting date as the subplot factor. There were two levels for each factor. The two tillage systems were conservation tillage (30% or more of the soil surface is covered with crop residue) and conventional tillage. The two cotton planting date window treatments were early May (normal planting) and early June (late planting). Five prevailing predacious ground beetles, Cicindela sexguttata F., Calosoma scrutator Drees, Pasimachus spp., Pterostichus spp., and Megacephala Carolina L. (Coleoptera: Carabidae), were monitored using pitfall traps at 2-week intervals from June 2002 to October 2003. The highest total number of ground beetles (6/trap) was observed on 9 July 2003. Cicindela sexguttata was the dominant ground dwelling predacious beetle among the five species. A significant difference between the two tillage systems was observed in the abundances of Pterostichus spp. and C. sexguttata. In 2002. significantly more Pterostichus spp. were recorded from conventional plots (0.27/trap) than were recorded from conservation tillage plots (0.05/trap). Significantly more C. sexguttata were recorded in 2003 from conservation plots (3.77/trap) than were recorded from conventional tillage plots (1.04/trap). There was a significant interaction between year and tillage treatments. However, there was no significant difference in the abundances of M. Carolina and Pasimachus spp. between the two tillage practices in either of the two years. M. Carolina numbers were significantly higher in late-planted cotton compared with those observed in normal-planted cotton. However, planting date window had no significant influence on the activity patterns of the other species. Ground beetle species abundance, diversity, and species richness were significantly higher in conservation tillage plots. This suggests that field conditions arising from the practice of conservation tillage may support higher predacious ground beetle activity than might be observed under field conditions arising from conventional tillage practices.