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Plants & Biodiversity

Why Trees Need the Right Soil pH

By RISC | 3 weeks ago

Soil isn’t just a solid foundation for trees but a source of essential nutrients that can help them thrive.Trees need 14 types of nutrients for growth:6 macronutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S). These are essential for growth and are required in large amounts. A deficiency can stunt growth and cause the plant to wilt or even die.8 micronutrients: iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), molybdenum (Mo), nickel (Ni), and chlorine (Cl). Although required in smaller quantities, these nutrients are just as vital for plant health.Soil typically has these nutrients but how well plants can absorb them depends on the soil’s pH level, which affects their solubility in a form that plants can absorb.The optimal pH for soil is about 6.0 to 6.5. If the pH is too high or too low, some nutrients become less soluble and unavailable for plants. With a pH below 6, phosphorus becomes less soluble. Highly acidic soil can reduce yields and cause short and swollen roots with damaged tips.We can fix these problems. With acidic soils, use lime-containing materials such as wood ash, crushed limestone, quicklime, or dolomite. With alkaline soils, apply aluminum sulfate or sulfur.Story by: Nakarin Phongphaew, Intern from Department of Botany, Faculty of Science, Chulalongkorn University and Thanawat Jinjarak, senior researcher Environmental Department Urban Environmental & Biodiversity Engineer, RISC

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Why Do City Trees Have Fewer Blooms?

By RISC | 3 weeks ago

Trees in nature often bloom beautifully, giving us wonderful blossoms to enjoy. But have you noticed that urban trees seem to flower less?So what factors affect how tree bloom? Flowering is governed by internal factors, such as shorter or longer days and the tree’s maturity, as well as external factors like water and pruning.City trees are often exposed to artificial lighting at night (read more: https://bit.ly/3rF7P5g). Research has found that some species flower less with limited or interrupted nighttime darkness, even if trees reach the right age. Trees shaded by buildings can also get less sunlight.Certain tree species bloom during dry seasons. Water stress triggers flowering as a survival mechanism. But urban trees are frequently watered year-round, reducing this response.To ensure city trees bloom seasonally, it’s essential to start with tree species suited to the local environment. Spaces should provide adequate exposure to both sunlight and artificial light. Care should mimic natural conditions and stimulate seasonal flowering. The result will be a beautiful city with charming urban spaces.Story by: Siriwan Sukngam, Intern from Department of Botany, Faculty of Science, Chulalongkorn University and Thanawat Jinjarak, senior researcher Environmental Department Urban Environmental & Biodiversity Engineer, RISC Reference by At gardare. (ม.ป.ป.). ปัจจัยที่มีผลต่อการเจริญเติบโตของไม้ประดับ. [ออนไลน์]. แหล่งที่มา:  https://researchex.mju.ac.th/agikl/index.php/knowledge/27-flowers/garden-tree/151-gardentree-4​มูลนิธิโครงการสารานุกรมไทยสำหรับเยาวชน. (ม.ป.ป.). การเกิดดอก. [ออนไลน์]. แหล่งที่มา: https://www.saranukromthai.or.th/sub/book/book.php?book=5&chap=2&page=t5-2-infodetail12.html​อมรธัช อุนจะนำ. การออกดอกและการติดผลของต้นไม้. พืชสวน. 5(1), 17-22​sd perspectives. (2562, 22 เมษายน). พื้นที่สีเขียว&ต้นไม้ในโครงการอสังหาฯ คืออีกสิ่งช่วยตัดสินใจซื้อ !. [ออนไลน์]. แหล่งที่มา: https://www.sdperspectives.com/next-gen/sansiri-tree-story-green-mission/​บ้านและสวน. (2563, 4 เมษายน). ตัดไม้ดอก อย่างไรให้ออกดอกสวย ลำต้นไม่โทรม?. [ออนไลน์]. แหล่งที่มา: https://www.baanlaesuan.com/185555/baanlaesuan-school/trim-flower​Park, Y.G., Jeong, B.R. Both the Quality and Positioning of the Night Interruption Light are Important for Flowering and Plant Extension Growth. J Plant Growth Regul 39, 583–593 (2020). https://doi.org/10.1007/s00344-019-10002-5​พจนีย์ แสงมณี. 2563. ผลของการตัดแต่งกิ่งและจัดการธาตุอาหารที่มีต่อการเจริญเติบโตและผลผลิตของมะม่วงหิมพานต์. วารสารเกษตร. 36(3), 313-319

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Trees Have Many More Types of Root than You Thought

By RISC | 1 month ago

You know that trees have taproots, lateral roots branching from them, and fibrous roots… But do you know about all the others, including some you mightn’t realize are roots?Taproots and lateral roots are among the best-known types of root. They anchor plants to the soil and absorb water and nutrients that go to trunks for growth. But trees also develop adventitious roots for challenging environments where survival can be tough. These specialized roots come in many fascinating forms:Prop roots develop from the trunk under stressful conditions, such as flooding or soft soil. They provide extra support so the tree stays upright. These roots often appear as woody structures growing from the stem. A classic example is in mangroves in coastal wetlands.Storage roots store nutrients within their structure and have diverse shapes, such as conical, fusiform, napiform (heart-shaped), and tuberous. Plants with storage roots include cassava, carrots, and beets, though we may not recognize them as roots at first glance.Aerial roots grow above the ground and serve as anchors on various surfaces, such as those in climbing plants. These roots can contain chloroplasts capable of photosynthesis, giving them a distinct green appearance, as seen in orchid aerial roots.Air roots play a role in gas exchange and oxygen transport to submerged roots in the soil. For example, pneumatophores of the white mangrove rise above the ground to access oxygen in waterlogged environments, where roots buried in soil lack adequate air.Parasitic roots penetrate the roots of other plants to extract nutrients, acting as their primary food source. These roots often harm the host plant, stunting its growth and, in severe cases, causing it to wither and die.Buttress roots are an adaptation of certain trees for environments such as near water bodies or in shallow soils. When taproots cannot penetrate deep into the ground, buttress roots spread out from the base of the trunk, forming large, flat structures to provide stability and support.Story by: Nakarin Phongphaew, Intern from Department of Botany, Faculty of Science, Chulalongkorn University and Thanawat Jinjarak, senior researcher Environmental Department Urban Environmental & Biodiversity Engineer, RISC

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Why Is Water a Danger for Plants?

By RISC | 1 month ago

Trees are easy to plant but much harder to grow! Keeping them healthy takes knowledge...The factors that affect plants include sunlight, soil, water, air, temperature, and fertilizers. Water is especially critical. Too little and they’ll wither and die. Too much and they can catch diseases and die.Rootzone soil has 3 key components: soil particles, air-filled pores, and water. Regular watering without considering environmental conditions can lead to waterlogged soil and pores. This situation can lead to root rot, lack of oxygen for roots, and moisture-linked diseases such as fungal infections. Once fungi penetrate roots, they can spread throughout the stem and propagate via air and water. These problems prevent roots absorbing water and nutrients effectively, halting the tree's growth.So the right amount of water is a vital for healthy plants. Regularly checking soil conditions and moisture levels, as well as adjusting the water quantity based on weather and plant needs, can minimize the risks of overwatering. Story by: Siriwan Sukngam, Intern from Department of Botany, Faculty of Science, Chulalongkorn University and Thanawat Jinjarak, senior researcher Environmental Department Urban Environmental & Biodiversity Engineer, RISCReference:กรมส่งเสริมการเษตร. 2558. การใช้น้ำอย่างรู้คุณค่าในการปลูกพืชผัก และพืชสมุนไพร. พิมพ์ครั้งที่ 1. https://esc.doae.go.th/vegetable/​กรมส่งเสริมการเษตร. หากพืชได้รับน้ำมากหรือน้อยเกินไป จะเกิดผลเสียอย่างไร. ​ยงยุทธ โอสถสภา. 2565. เข้าใจดิน ดูแลดิน หลังน้ำท่วม. [ออนไลน์]. แหล่งที่มา: [ออนไลน์]. แหล่งที่มา: https://www.doae.go.th/answers/หากพืชได้รับน้ำมากหรือ/​เนชั่นแนล จีโอกราฟฟิก ประเทศไทย. เชื้อราในพืช ความสัมพันธ์ของสิ่งมีชีวิตจากภาวะพึ่งพาอาศัย ไปจนถึงภาวะปรสิต. [ออนไลน์]. แหล่งที่มา: https://ngthai.com/science/48232/believe-in-plants/

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How Trees Can Forecast the Weather

By RISC | 1 month ago

We all know how a tree's rings reveal its age. But did you know how the color and width of these rings tell us about past weather?Trees respond to their environment through biological processes that are crucial to their survival. These responses include changes in growth due to moisture and temperature fluctuations, seasonal adaptations like leaf shedding, and alerts sent by roots or airborne chemicals when disturbed. Even the growth of trunks and branches adjusts to withstand wind forces.Weather patterns, such as consistent rainfall or extreme heat, affect flowering and growth. Some trees store energy to wait for optimal conditions before reproducing. A striking example is the Yangna (Dipterocarpus alatus).Yangna trees have a remarkable ability to forecast weather based on their flowering and fruiting patterns. These behaviors are influenced by environmental factors like humidity, temperature, and rainfall. A Yangna with abundant flowers and fruits often signals an impending rainy season with lots of rainfall. Prof. Nopphorn Nontapa studied the relationship between Yangna flowering and rainfall for over a decade to collect data for predicting rainfall in various locations. The patterns can even provide insight into the direction of approaching storms.Trees don’t forecast weather in the same way we do. But their evolutionary adaptations are highly effective for survival. The older a tree, the more accurate its record of local climate conditions becomes.​Story by: Kotchakorn Rattanama, Biodiversity Researcher, RISC​Reference by Forest Plantation School

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Why Don’t Spiders Get Stuck in Their Webs?​

By RISC | 4 months ago

What’s stronger than steel and more flexible than rubber? Spider silk!​Spider silk is incredibly tough. If a strand were as thick as a pencil, it could stop a Boeing 747 in mid-flight. Think about Spider-Man shooting his webs when fighting villains or swinging between buildings… Those webs are incredibly strong!But there’s more to spider silk than just its strength.​Spider silk has different types of threads – sticky and non-sticky. Each thread serves a unique purpose. Spiders have 7 silk-producing glands in their abdomen, and each gland produces a different type of silk:​• Glandula Aggregate: Produces sticky silk.​• Glandula Ampulleceae – major: Produces strong, durable silk for walking.​• Glandula Ampulleceae – minor: Produces temporary walking silk during web-making.​• Glandula Pyrifomes: Produces adhesive silk for attachment.​• Glandula Anciniformes: Produces flexible capture silk for catching prey.​• Glandula Tubiliformes: Produces silk for building nests or egg sacs.​• Glandula Corontae: Produces sticky, adhesive silk.​Since spiders create these fibers, they know exactly where to walk on their webs without getting stuck. Their legs also have tiny hairs and special hooks that allow them to walk confidently on the sticky strands.​Beyond catching insects or prey, spider silk has another intriguing function: it helps spiders sense their environment through vibrations. With such incredible properties, spider silk has inspired many innovations, including bulletproof vests, safety belts, and even surgical sutures.​Nature’s wonders surround us every day. Stay tuned for more on the world’s amazing creatures from RISC.​​Story by: Kotchakorn Rattanama, Biodiversity Researcher, RISC​​References:​Esme Mathis. (2022). Australian Geographic. "Unspinning the secrets of spider webs." From: https://www.australiangeographic.com.au/news/2024/07/cobra-bite-treatment/ (Accessed on 1 August 2024)​http://oservice.skru.ac.th/ebookft/601/chapter_7.pdf (Accessed on 1 August 2024)​

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Watch Out for Animal Visitors in the Rainy Season…

By RISC | 7 months ago

Rain in the rainy season can bring some wildlife into our homes and gardens that isn’t always welcome. But we can stay safe with some simple steps.​​Thailand’s rainy season is already underway. In addition to taking extra care when we travel, we should stay alert for various creatures. RISC has tips for dealing with 3 types of creature so both you and they can avoid harm. ​Snakes can be a concern. They typically live in bushes, trees, and damp undergrowth. But they can come out in search of rats. Keep your home clean to ensure there are no food sources or hiding spots. If you find a snake near your home that you fear might be dangerous, you can call 199 for immediate assistance.​Rove beetles are another worry. They need humidity to breed and prefer the night. They produce a toxin called paederin that can cause skin irritation, redness, and blisters. Keep all your windows and doors closed and check your bed or seating area often. If you meet one, blow or shake it away without touching it.​Tiny creatures like centipedes and scorpions can also be found in damp corners and leaf piles. Their toxins can harm humans and pets. An accidental touch can induce allergies. And, in extreme cases, severe allergies can result in death.​During the rainy season keep your home and garden tidy, eliminating corners like piles of materials, wood chips, and leaves. Repair cracks and soil subsidence to keep these creatures out.​Kotchakorn Rattanama, Biodiversity Researcher, RISC ​Reference:​Health Literacy and Communication Promotion Division, Department of Health, Ministry of Public Health​

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Trees Make the Best Fences

By RISC | 8 months ago

Many people experience privacy issues in their homes. But walls and fences can be costly. How can we solve this problem?​A low-cost option is to create a tree fence.​Fences make homes more comfortable. And planting trees benefits us in many ways, including physical, scenic, mental, and economic. Planting trees as a barrier stops people looking in. The plants can hide unattractive areas and reduce noise too.Trees with a lot of leaves and thick foliage in lines 15-30 meters wide and at the appropriate height for the sound source can absorb up to 5-10 dB. Their colors also enhance the view.​When choosing trees for a fence or along a fence, start with dense shrubs with many leaves that are easy to maintain. Plants can be put into 4 categories.​- Plants can be used to conceal undesirable views or use as a fence such as Ochna integerrima, Flacourtia indica, Uvaria siamensis, Dasymaschalon lomentaceum Finet & Gagnep, Wrightia religiosa Benth., Harrisonia perforata (Blanco) Merr., Murraya paniculata (L.) Jack., Streblus asper Lour., Carmona retusa (Vahl) Masam., Ficus Benjamina L., Bauhinia acuminata, Phyllodium elegans (Lour.) Desv., Melastoma malabathricum L., Olax scandens Roxb., Vietnamosasa pusilla, Rhodamnia dumetorum (DC.) Merr. & L.M.Perry, Memecylon edule Roxb., Holarrhena curtisii King et Gamble, Gardenia carinata Wall. ex. Roxb., Prismatomeris tetrandra (Rox.b.) K.Schum. var.malayana (Ridl.) Johans. and Chamaecyparis lawsoniana.​- Plant lower-level plants or ground cover in the foreground can create an open space and vista, such as Zingiber zerumbet (L.) Smith., Crinum amoenum Roxb., Alpinia conchigera Griff., Pavetta indica L., Rhinacanthus nasutus (Linn.) Kurz., and Tacca leontopetaloides. ​- Ornamental plants for home decoration tend to be flowering plants or small plants such as Curcuma sessilis Gage., Hegnera obcordata (Miq.) Schindl, Geodorum densiflorum (Lam.) Schltr., Barleria strigosa Willd., Ageratum conyzoides L., and Costus speciosus (Koen.) Sm.​- Unique plants and tree species with distinct traits include Phyllodium elegans (Lour.) Desv., Melastoma malabathricum L., Dasymaschalon lomentaceum Finet et Gagnep, Commelina diffusa, Gardenia carinata Wall. ex. Roxb., Antidesma acidum Retz., Uraria crinita (L.) Desv. ex DC., and Acalypha wikesiana Muell-Arg.​If you’re interested in creating tree walls, consider using these plants. You could end up with a magnificent fence and more privacy.​Story by Patcharin Pumjae, Intern form Department of Plant Biology, Faculty of Forestry, Kasetsart University and Thanawat Jinjaruk, Senior Researcher, Environment Division and Urban Environmental & Biodiversity Engineer, RISC​References:​http://forprod.forest.go.th/forprod/techtransfer/document/%E0%B8%84%E0%B8%B9%E0%B9%88%E0%B8%A1%E0%B8%B7%E0%B8%AD%E0%B8%9D%E0%B8%B6%E0%B8%81%E0%B8%AD%E0%B8%9A%E0%B8%A3%E0%B8%A1/%E0%B8%A3%E0%B8%B8%E0%B8%81%E0%B8%82%E0%B8%81%E0%B8%A3/%E0%B8%9B%E0%B9%88%E0%B8%B2%E0%B9%84%E0%B8%A1%E0%B9%89%E0%B9%83%E0%B8%99%E0%B9%80%E0%B8%82%E0%B8%95%E0%B9%80%E0%B8%A1%E0%B8%B7%E0%B8%AD%E0%B8%87%E0%B9%83%E0%B8%99%E0%B8%A1%E0%B8%B8%E0%B8%A1%E0%B8%A1%E0%B8%AD%E0%B8%87%E0%B8%82%E0%B8%AD%E0%B8%87%E0%B8%A0%E0%B8%B9%E0%B8%A1%E0%B8%B4%E0%B8%AA%E0%B8%96%E0%B8%B2%E0%B8%9B%E0%B8%B1%E0%B8%95%E0%B8%A2%E0%B9%8C.pdf ​http://old-book.ru.ac.th/e-book/a/AT459/at459-1.pdf ​https://medthai.com/ ​http://dspace.bu.ac.th/bitstream/123456789/4903/1/Saksorn_Chan.pdf ​https://readthecloud.co/best-plants-for-fence-line/ ​Tanaka, K., Ikeda, S., Kimura, R. & Simazawa, K. (1979). The function of forests in soundproofing. Bulletin Tottori University Foresta, 11, 77–102. ​Cook, D.I. and Van Haverbeke, D.F. (1972). Tree, shrub and landforms for noise control. Journal of soil and water conservation 27, 259-261.​

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Which Trees to Plant by Buildings?​

By RISC | 11 months ago

In the last article "Should We Grow Trees by Buildings?" (read more at https://bit.ly/3UpPWTH), we saw the positive and negative effects of having trees nearby. But we can boost the upside by choosing the right species.​A tall-short, thick-thin, and wild-shaped tree arrangement enhances both beauty and shade. Trees can influence how wind enters the structure. Planting shrubs outside can help control dust. Perennials with tall trunks allow air to flow in at ground level. Dense 2-meter-tall shrubs can block or moderate wind. Big trees to the west can reduce afternoon heat.​Trees with hairs on their leaf surfaces can protect allergy sufferers by trapping particulates. They’ll also help regulate the air quality around the structure. These trees will best trap particles if planted in rows and on many levels.​Perennials like Gardenia sootepensis Hutch. and Schoutenia glomerata, shrubs like Nyctanthes arbor-tristis and Holarrhena pubescens, and ivy plants like Afgekia mahidoliae, Thunbergia grandiflora, Combretum indicum, and Petrea volubilis are examples of trees that trap particles. This group of ivies can also be utilized as a door arch for decoration. Take care if you dislike strong-smelling plants and select perennial to avoid or lessen the risk of big trees collapsing. Trees like Fagraea fragrans and Fagraea racemosa Javanica  have deep roots and won't harm the building's construction.​The advantages of growing trees near buildings have already been covered. There are many reasons why buildings should have trees around them. RISC encourages everyone to plant trees. We can start small indoors or start from our homes.​Story by Chananya Kasempiyarom, Intern from Department of Plant Science, Faculty of Science, Mahidol University, and Thanawat Jinjaruk, Senior Researcher, Environment Division and Urban Environmental & Biodiversity Engineer, RISC​References: ​https://www.baanlaesuan.com/134892/plant-scoop/dust_prevent​https://www.banidea.com/shade-trees-with-non-invasive-root-systems/​The essential guide to Architecture and Interior designing from Instagram : 07sketches​

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Should We Grow Trees by Buildings?

By RISC | 1 year ago

Trees have both positive and negative aspects. They’re attractive, clean the air, reduce the temperature but can also cause problems.​Here are some views from students, engineers, architects, biologists, and officials about trees near buildings.​More than 80% said trees near buildings provide shade, visual comfort, air purification, look attractive, and cool indoor and outdoor temperatures. 40% said trees provide habitats for small animals. Others mentioned topics including fruits, gardening, privacy, and flood mitigation.​But trees can also have a negative impact. 70% mentioned poisonous plants. 60% cited fallen leaves and branches. 50% reported root problems with buildings. Other issues include excessive odor from flowers, blocked perspectives, and trees falling on properties.​There are ways to mitigate and prevent such problems. ​A key solution is to choose appropriate trees, avoiding deciduous trees like Albzia saman (Jacq.) Merr., Millingtonia hortensis L. F., and Alstonia scholaris to prevent fallen leaves, strong odor from flowers, and broken branches. Tabernaemontana divaricata (L.) R.Br. ex Roem. & Schult., Ficus annulata Blume., Ficus annulata Blume can be more suitable.​Understanding each type of tree and how to care for and prune it can help them last longer and cause fewer problems.​Stay tuned for more information on how and where to plant trees to best benefit.​Story by Chananya Kasempiyarom, Intern from Department of Plant Science, Faculty of Science, Mahidol University and Thanawat Jinjaruk, Senior Researcher, Environment Division and Urban Environmental & Biodiversity Engineer, RISC ​

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