排序方式： 共有7条查询结果，搜索用时 46 毫秒
1
1.
Campera Marco Budiadi Budiadi Bušina Tomáš Fathoni Baladzuri Hafizh Dermody Janine Nijman Vincent Imron Muhammad Ali Nekaris K. A. I. 《Agroforestry Systems》2022,96(5-6):829-841
Agroforestry Systems - Complex agroforestry systems are suggested as a possible solution to reduce the effects of deforestation in the tropics while enhancing the livelihoods of local human... 相似文献
2.
Myanmar is home to Asiatic black bears and sun bears. We gained insight into illegal hunting and trade of these species in and out of Myanmar through conversations with 40 self-declared bear poachers. All respondents were males who typically killed or caught one to three bears a year, mostly by setting snares. There was a preference for Asiatic black bear. Perceptions were that bears were less abundant now than 5 years ago, but it was not more arduous to obtain one. Most poachers (75%) consumed less valuable parts and sold the remainder, whereas others trapped only to sell. Preferred tradable parts were gall bladder, meat, and paws. Chinese nationals or Burmese of Chinese descent were mentioned as playing key roles (ordering, buying, selling) in trade. Instead of focusing on poachers, we recommend that authorities focus on disrupting trade networks and markets. Cooperation with neighboring countries, especially China, is needed to stem the flow of bear parts. 相似文献
3.
Charles M. Nijman 《Irrigation and Drainage Systems》1992,6(2):85-112
This paper focuses on the performance evaluation of different decision-making processes that lead to overall irrigation system performance. First, the key decisions that contribute to the overall system performance in terms of water delivery are identified by means of an analytical framework for irrigation management. Consequently, these key decisions are described briefly and their potential performance indicators listed. The actual use of these performance indicators by two Sri Lankan agencies, government and donor are given in the same lists, which makes it possible to see what these organizations are actually aiming for with respect to water delivery. This approach makes it clear that at the time present the Sri Lankan agencies, government and donor do not care about the water delivery performance. Possibilities for improvement and the role of the different actors are discussed which suggests, at least in Sri Lanka, that initiation of successful performance improvement may have to come from the governments and donors, rather than from the managing agencies themselves. 相似文献
4.
In view of the continued decline in tropical forest cover around the globe, forest restoration has become a key tool in tropical rainforest conservation. One of the main - and least expensive - restoration strategies is natural forest regeneration. By aiding forest seed influx both into disturbed and undisturbed habitats, frugivorous birds facilitate forest regeneration. This study focuses on the tolerance of a frugivorous bird community to anthropogenic habitat disturbance within the broader context of natural forest regeneration with conservation purposes. It was carried out in the tropical cloud forest of Costa Rica’s Talamanca Mountains. Bird community response and tolerance to habitat disturbance was assessed by comparing bird presence and densities along a disturbance gradient, ranging from open pastures to closed mature forests. Birds were censused along nine transects applying the variable width line transect procedure. Forty relevant frugivorous bird species were observed during 102 h of survey time. Densities were calculated for 33 species; nine species responded negatively to increasing level of disturbance and nine others positively. Results indicate that large frugivores are generally moderately tolerant to intermediate, but intolerant to severe habitat disturbance, and that tolerance is often higher for medium and small frugivores. It appears that moderately disturbed habitats in tropical cloud forests are highly suitable for restoration through natural regeneration aided by frugivorous birds. Due to a lack of large forest seed dispersers, severely disturbed habitats appear less suitable. 相似文献
5.
Fitt B. D. L. Nijman D. J. 《European journal of plant pathology / European Foundation for Plant Pathology》1983,89(5):198-202
Splash dispersal ofPseudocercosporella herpotrichoides spores from infected wheat straw was investigated using simulated rainfall (rate 13.8l h–1 m–2, volume mean diameter 2.9 mm) and wind (2 m sec–1) in a raintower/wind tunnel complex. Spores were deposited on the floor of the wind tunnel up to 1 m upwind and 2.5 m downwind from the centre of the straw and impacted on vertical surfaces at heights up to 36 cm above it. Fewer spores were collected with increasing distance from the straw and with increasing height. Most spore-carrying splash droplets were in the size range 400–600 m and very few were less than 200 m.Our results show that these spores are generally dispersed over short distance, which is consistent with field observations.Samenvatting Spetterverspreiding vanPseudocercosporella herpotrichoides van besmet tarwestro werd onderzocht met behulp van nagebootste regen (13,8 l uur–1 m–2, gemiddelde druppel diameter 2,9 mm) en wind (snelheid 2 m sec–1) in een proefopstelling van een regentoren en een windtunnel. Sporen werden op de vloer van de windtunnel gedeponeerd tot 1 m afstand tegen de wind in, gerekend vanaf het centrum van het tarwestro, en met de wind mee tot 2,5 m afstand daarvan. Op verticale vlakken werden sporen op een hoogte van 0 tot 36 cm boven de vloer van de windtunnel opgevangen. Naarmate de afstand en de hoogte toenamen werden er minder sporen gevonden. De meeste spetters met sporen hadden een diameter van 400–600 m en slechts enkele waren kleiner dan 200 m.Onze resultaten tonen aan dat de sporen in het algemeen slechts over korte afstanden verspreid worden, hetgeen overeenkomt met veldwaarnemingen. 相似文献
6.
7.
Sjaak F. L. Klis Nic J. Nijman Henk P. M. Vijverberg Joep van den Bercken 《Pest management science》1991,33(2):213-222
Phenylpyrazoles constitute a newly developed class of chemicals with insecticidal and herbicidal properties. In acute toxicity experiments in rats, near-lethal doses of phenylpyrazoles produce neurotoxic symptoms with an unknown mode of action. We have investigated the effects of two phenylpyrazoles, SLA4722 and SLA4685, in the frog neuromuscular junction and in the clonal muscle cell line BC3H-1. In the frog neuromuscular junction SLA4722 at concentrations ? 10?5 M caused a pronounced increase in the frequency of miniature endplate potentials (MEPPs). SLA4685 caused a similar increase but was less potent. In the clonal muscle cell line BC3H-1, SLA4685 produced a concentration-dependent block of the acetylcholine (ACh) response (IC50 = 2.4(±0.3) × 10?5 M). At 10?6 M a slight potentiating effect of SLA4685 on the ACh response was observed. SLA4722 was less potent in this preparation. The increased transmitter release might, at least partly, be responsible for the excitatory effects of the phenylpyrazoles in intact animals. 相似文献
1