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In 2007, REDD+ emerged as the leading option for early climate change mitigation. In 2010, after the failure of negotiations at the Copenhagen COP, observers cited REDD+ projects and other subnational initiatives as examples of the polycentric governance (based on multiple independent actors operating at multiple levels) necessary to move climate change mitigation forward in the absence of a binding international agreement. This paper examines the ways subnational initiatives can and cannot play this role, based on the experiences and opinions of 23 REDD+ proponent organizations in six countries. These proponents have tested various approaches to climate change mitigation, demonstrating the value of a polycentric approach for promoting innovation and learning. However, from our sample, six initiatives have closed, four no longer label themselves as REDD+, only four are selling carbon credits, and less than half view conditional incentives (initially the core innovation of REDD+) as their most important intervention. While polycentric governance in REDD+ has benefits, it will not enable implementation of REDD+ as originally conceived unless accompanied by a binding international agreement.En 2007, la REDD+ est apparue comme la solution prépondérante en matière d'atténuation précoce du changement climatique. En 2010, après l'échec des négociations à la COP de Copenhague, les observateurs ont mis en avant les projets et les autres initiatives infranationales de REDD+ en tant qu'exemples de la gouvernance polycentrique (reposant sur plusieurs acteurs indépendants intervenant à des niveaux différents) nécessaire pour faire avancer l'atténuation du changement climatique en l'absence d'accord international contraignant. Le présent article examine les cas dans lesquels les initiatives infranationales peuvent effectivement jouer ce rôle et ceux dans lesquels elles ne le peuvent pas, à partir de l'analyse d'expériences et d'opinions collectées auprès de 23 organisations promotrices d'initiatives REDD+ dans six pays. L'étude des diverses approches de l'atténuation du changement climatique testées par ces promoteurs de la REDD+ met en évidence l'intérêt d'une approche polycentrique de la promotion de l'innovation et de l'apprentissage. Cependant, parmi les initiatives de l'échantillon étudié, six n'existent plus, quatre ne se considèrent plus comme relevant du mécanisme REDD+, quatre seulement commercialisent des crédits carbone, et moins de la moitié considèrent les incitations conditionnelles (l'innovation centrale de la REDD+ au départ) comme leur intervention la plus importante. Si la gouvernance polycentrique de la REDD+ comporte des avantages, elle ne permettra pas de mettre en oeuvre le mécanisme comme il avait été conçu à l'origine si elle n'est pas accompagnée d'un accord international contraignant.

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Four browse legume foliages (leaves and pod fruits) from three species of Acacia (A. polyacantha, A. tortilis, A. nilotica) and Dichrostachys sp. native to Tanzania were evaluated for nutritive potential to establish levels and effect of normal phenolics and tannins antinutritive factors (ANFs) on in vitro feed digestibility (IVD). Total extractable phenolics (TP), tannins (TT) were estimated by Folin-Ciocalteu assay, and condensed tannins (CT) by butanol/HCl assay. In leaves, total proanthocyanidins were assayed into constituent anthocyanidins' flavonoids by high performance liquid chromatography (HPLC). Organic matter degradability (OMD) was estimated in vitro by gas production technique. Adverse effects of tannin's ANF on IVD were assessed by polyethylene glycol (PEG) tannin bioassay. Crude protein (CP) varied (P<0.05) between fodder species and foliages. Leaves had (P<0.05) higher CP (141-194 g/kg DM) in Dichrostachys sp. and A polyacantha, respectively, compared to pods (133-142 g/kg DM) in A. tortilis and Dichrostachys sp., respectively. Neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) va- . polyacantha), and 0.009 (A. nilotica) to 4.392 (Dichrostachys sp.) for delphinidins, cyanidins and pelargonidin, respectively. The browse foliages had relatively high tannin content greater than 5% DM, a beneficial level in animal feeding and nutrition, and thus could impair feed digestibility. OMD varied significantly (P<0.05) both between fodder species and foliage components. Pods had higher (P<0.05) gas production (GP) and OMD than leaves. Addition of PEG improved (P<0.05) gas production, IVD and metabolizable energy (ME) in leaves and pods by binding tannins. Leaves had higher response on gas production and IVD due to PEG treatment compared to pods except A. nilotica. Improved gas production and digestibility due to PEG treatment indicate nutritive potential in browse fodder previously depressed by tannin ANFs.Therefore, phenolics and tannins ANFs could limit utilization of browse fodder nutritive potential as supplements to ruminants consuming low quality roughages. Utilization of browse legume fodder could be optimized through reduction of tannin antinutritive activity. Under farmers' conditions, optimal utilization of browse could be achieved through feeding a mixture of tanniferous browse with other feeds especially high in nitrogen to dilute tannin antinutritive activity.

Information is lacking on the potential of leguminous fodder trees such as Leucaena leucocephala as a feed resource to supplement the native forages in traditional grazing management systems in the tropics. Two studies were conducted (1) to assess traditional fodder banks' forage nutritive potential on animal production, and (2) to investigate the effect of Leucaena leucocephala leaf meal (LLM) supplementation on growth of steers grazing standing hay basal forages in the dry season. The traditional forages had low nutritive values indicated by low mean crude protein (CP) of 23 g kg À1 dry matter (DM), and high fibre contents of 717, 546 and 153 g kg À1 DM for neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL), respectively. The forages were poorly degraded in sacco and had low metabolisable energy (ME) (4.2-4.6 MJ kg À1 DM). Mean washing losses A, slowly degradable DM fraction, B, potential degradability, (A+B) and mean 48 h DM degradability (DMD) of grazing land forages were 70, 471, 541 and 326 g kg À1 DM, respectively. In the supplementation study, 16 growing steers (160.8±0.24 kg) were randomly allocated into four groups, in a completely randomized design. Four LLM treatment diets (T1, T2, T3 and T4), with four levels: 0, 0.4, 0.6 and 0.8 kg DM for control, low, medium and high LLM levels, respectively, were randomly allocated to the animals in the four groups for 70 days (d). LLM supplementation ( p<0.05) improved mean weight gain from À0.30 to 0.26 kg steer À1 d À1 , for T1 and T4, respectively. Steers on T4 gained ( p<0.05) more weight compared to the animals in T1 and T2, though there was no ( p>0.05) difference in weight gains between animals on T3 and T4 (0.14 vs. 0.26 kg steer À1 d À1 , respectively). Standing hay basal forages alone could not sustain animal productivity during dry seasons unless corrected for protein. Higher levels of LLM supplementation prevented weight losses and improved the performance of grazing steers, a management practice thought appropriate to low income pastoralists in semiarid western Tanzania.