To estimate species loss from habitat destruction, ecologists typically use species-area relationships, but this approach neglects the spatial pattern of habitat fragmentation. Here, we provide new, easily applied, analytical methods that place upper and lower bounds on immediate species loss at any spatial scale and for any spatial pattern of habitat loss. Our formulas are expressed in terms of what we name the 'Preston function', which describes triphasic species-area relationships for contiguous regions. We apply our method to case studies of deforestation and tropical tree species loss at three different scales: a 50 ha forest plot in Panama, the tropical city-state of Singapore and the Brazilian Amazon. Our results show that immediate species loss is somewhat insensitive to fragmentation pattern at small scales but highly sensitive at larger scales: predicted species loss in the Amazon varies by a factor of 16 across different spatial structures of habitat loss.

The unique plant communities of the freshwater swamp forests of southern Johor (Malaysia) and Singapore attracted the attention of E.J.H. Corner, but there have been no comprehensive follow-up studies to his seminal work. Meanwhile, freshwater swamp forests in the region have been mostly lost to logging and in-filling for plantations or urban development. The Nee Soon catchment contains the last substantial tract of this forest type in Singapore. We collated the rediscoveries of vascular plant species presumed Nationally Extinct in the 2 nd and latest edition of the Singapore Red Data Book, and new records for the Singapore vascular plant flora from the Nee Soon catchment, including those that we found and collected through the establishment and survey of 40 vegetation plots, each 20 × 20 m. We have identified 672 species from 117 families, of which 288 are trees from 60 families represented by at least one stem ≥ 5 cm DBH. The catchment is especially species rich and abundant in the Myristicaceae. In the last ten years, 53 rediscoveries, 11 new species records, and two new varietal records have been uncovered from (or can be found in) the Nee Soon catchment. The Nee Soon freshwater swamp forest is one of Singapore's most valuable botanical areas, and warrants sustained conservation effort and study.

Questions:How do abiotic conditions, forest structure, as well as taxonomic and functional diversities and composition recover after wind-generated treefalls? Do young and old-growth secondary forests differ in their responses?Location: Mandai region of the Central Catchment Nature Reserve, Singapore, where extensive treefalls occurred during an unusually powerful windstorm in 2011. Southeast Asia.Methods: Soil nitrogen, phosphorous, potassium, canopy cover, leaf litter depth, coarse woody debris, and woody stems ≥1-cm diameter were measured and identified in 10 × 10 m plots. Twenty-six plots were located in treefall areas and 14 plots were located in relatively unaffected areas, with equal numbers in young and old-growth secondary forest types. The first round of surveys took place within 3-6 months of the windstorm event and yearly re-surveys were conducted until 2015. Specific leaf area, leaf dry matter content, leaf thickness, woody density, maximum plant height, and seed dry mass were measured or derived from various sources. Results:There was a pulse of soil nutrient availability in both affected and unaffected areas 1 year after the wind event. Canopy cover and basal area in the affected areas recovered to similar levels as unaffected areas by the second year, and coarse woody debris by the fourth year. In affected plots, taxonomic and functional diversities increased and overshot that of-and taxonomic composition diverged from-unaffected plots after the second year. Young and old-growth secondary forest types mainly differed in the taxonomic composition of new recruits. However, there was no evidence of changes in functional composition towards resource-acquisitive strategies such as lower wood density or higher specific leaf area. Conclusions:Abiotic conditions and basal area recovered rapidly within 2-4 years after the windstorm. Taxonomic composition in young and old-growth affected forests both diverged from unaffected forests but also from each other over time. K E Y W O R D Sblowdown, community composition, edaphic conditions, extreme weather, longitudinal study, plant functional traits, regeneration trajectory, tropical forest, wind disturbance, windthrow | 721 N. (2014). Seven-year responses of trees to experimental hurricane effects in a tropical rainforest, Puerto Rico. Forest Ecology and Management, 332,[64][65][66][67][68][69][70][71][72][73][74]. https ://doi.

Singapore (1°21'07.6"N 103°49'11.3"E) is a tropical island-state situated south of Peninsular Malaysia, and north of the Riau Archipelago. Similar to tropical areas elsewhere, Singapore's climate is characterised by abundant rainfall (mean annual: 2165.9 mm), and generally high temperature (diurnal range: 23-33°C) and humidity (mean annual relative: 83.9%) throughout the year (Meteorological Service Singapore, 2018). Singapore's terrain is generally low-lying, with about three quarters of the island below 15 m. The highest point is the summit of Bukit Timah, which is at 163.63 m elevation (Wong, 2011). In 1963, the land area was 581.5 km 2 , and by 2018 had increased to 724.2 km 2 through land reclamation (Singapore Land Authority, 2019). There are 62 offshore islands-the two largest (Pulau Ubin and Pulau Tekong) are located northeast of the main island, and the rest are mostly found south of the main island. Before the arrival of the British in 1819, Singapore was likely covered mostly by lowland mixed dipterocarp forest (Fig. 1), similar to the original forest that was dominant in this part of Southeast Asia (Corlett, 1991, 1992). Mangrove forest likely occurred near river mouths with the vegetation transiting into freshwater swamp forest further inland. Stretches of sandy beach and rocky shore would have lined parts of the coast. Early human settlements (fourteenth to eighteenth centuries) have been recorded at the mouths or estuaries of the Singapore River, Kallang River, Seletar River and Punggol River. Singapore underwent tremendous landscape and ecological transformation after British colonisation (see Corlett (1992) and O'Dempsey (2014) for detailed accounts). Large tracts of lowland dipterocarp rain forest were cleared for timber, then converted to plantations of various crops, including black pepper, gambier, and pineapple. By the early 1900s, most lowland dipterocarp rain forest had been cleared and the remaining few patches were mostly gazetted as forest reserves. Extensive black pepper and gambier plantations had rendered the soil infertile in many areas. After H.N. Ridley's arrival in Singapore in 1888 and his experiments with the excision method to tap rubber more effectively and sustainably, large areas were converted into rubber plantations (Wycherley, 1959; Wee & Corlett, 1986). Kampungs (traditional villages) also increased in number as the island became more developed. Mangrove habitats were also affected by over-exploitation although later, in 1939, Pandan and Kranji mangrove areas were gazetted as forest reserves to allow regeneration (Wee & Corlett, 1986). After Singapore became independent from Malaysia in 1965, the new island nation began to focus on its industrial infrastructure resulting in the discontinuation or down-scaling of many agriculture-based activities. The growth of public housing estates to cater to the basic needs of a growing population saw most residents of the rural kampungs eventually resettled to high-rise public housing by the 1990s. Plantations and kampungs were grad...

Extinction is a key issue in the assessment of global biodiversity. However, many extinction rate measures do not account for species that went extinct before they could be discovered. The highly developed island city-state of Singapore has one of the best-documented tropical floras in the world. This allowed us to estimate the total rate of floristic extinctions in Singapore since 1822 after accounting for sampling effort and crypto extinctions by collating herbaria records. Our database comprised 34,224 specimens from 2076 native species, of which 464 species (22%) were considered nationally extinct. We assumed that undiscovered species had the same annual per-species extinction rates as discovered species and that no undiscovered species remained extant. With classical and Bayesian algorithms, we estimated that 304 (95% confidence interval, 213-414) and 412 (95% credible interval, 313-534) additional species went extinct before they could be discovered, respectively; corresponding total extinction rate estimates were 32% and 35% (range 30-38%). We detected violations of our 2 assumptions that could cause our extinction estimates, particularly the absolute numbers, to be biased downward. Thus, our estimates should be treated as lower bounds. Our results illustrate the possible magnitudes of plant extirpations that can be expected in the tropics as development continues.

The plant diversity of Bukit Timah Nature Reserve (BTNR) is relatively well studied due to concerted effort over several decades, particularly as part of the worldwide system of ecological plots set up by the Center for Tropical Forest Science (CTFS), now called the Forest Global Earth Observatory. Publications arising from previous works have set baseline data for the species diversity, suggested that the forest resilience was greater than would be expected in such a small forest fragment, but that there was low recruitment of primary forest tree species into the secondary forest. In order to assess the overall vascular plant diversity, and to compare the diversity of the various forest types within BTNR to each other, 52 plots were set up, each 20 × 5 m, along nine different transects that covered the full range of topography and forest types, primary, old secondary and maturing secondary forests, within the reserve. The vascular plant diversity within each plot was recorded. In total, 1250 species in 148 families were recorded, including an additional 167 species newly listed for BTNR. The primary forest had the highest number of species not found in the other forest types. It nevertheless had a very large overlap with species in the old secondary forest but not with the maturing secondary forest.

Several new records of plant species previously unknown in Singapore are reported, along with records of species presumed to be nationally extinct which have been rediscovered. These reports are based on specimens collected during our recent surveys of the Bukit Timah Nature Reserve and previously unreported older specimens, all deposited in SING. Three species are reported as new records for Singapore: Scindapsus lucens Bogner & P.C.Boyce, Passiflora quadriglandulosa Rodschied and Tectaria nayarii Mazumdar. Scindapsus lucens is likely to be native and previously overlooked, whereas Passiflora quadriglandulosa and Tectaria nayarii are exotic species which have escaped from cultivation and become naturalised. Another 10 species are rediscoveries of taxa previously considered to be nationally extinct:

Neonauclea kranjiensis K.M.Wong & W.W.Seah, a newly diagnosed species from Singapore, is described. It most resembles Neonauclea excelsa (Blume) Merr. from which it differs in its smaller, narrowly elliptic leaves as well as smaller mature flowering heads. The taxa known as Neonauclea excelsa and N. calycina (DC.) Merr. in Java, Peninsular Malaysia and parts of Borneo are just one species to which the name Neonauclea excelsa must be applied. Neonauclea calycina continues to be recognised as a species in the Philippines pending further study.